Document evzymzOQ0119pEkDNJaQqkZKy

, INTER-OFFICE CORRESPONDENCE TO: Gerry Lloyd DATE: January 6, 1982 COPIES: Jim Boyette M. R. Zavon R. J. Schuttler FROM: T. M. Bri SUBJ: VCM MONITORING Hooker Chemical Company J/0. A 33.01 The enclosed article from the Journal of the American Industrial Hygiene Association presents a comparison of 3M, DuPont and GASBADGE passive organic vapor monitors with charcoal tubes. The study appears well controlled and the correlations are impressive. I am assembling an extensive literature reference file on passive monitors so if I can be of technical support to you on this matter, please call me. Jim Boyette at Addis sent me information about their VCM monitors. They have purchased a number of REAL Mini Monitors. The Mini Monitor works on a permeation principle which is less accepted and not as well validated as the diffusion systems mentioned above for organic vapor sampling. High humidity decreases the adsorption efficiency of charcoal diffusion systems when sampling for light hydrocarbon such as vinyl chloride. This may be an advantage for a permeation system in an area such as Baton Rouge. Enclosed are two papers on the REAL Mini Monitors. Since performance characteristics of the Mini Monitor are not fully documented, I suggest that a quality assurance program for sampling and analytical procedures be instituted if this system is to be used. Method validation is a must to have confidence in the results. If I can be of assistance, please call. I will be at Addis on January 14-15 and I will discuss this with Jim Boyette at that time. TMB/mrbOllOA Enclosures OCC 8214 The use of passive organic vapor monitors has been suggested as an alternative to the use of charcoal tubes with a portable pump as a method to assess a worker's exposure to organic compounds. This study simultaneously compares DuPont's. Abcor's, and 3M's passive monitors to the charcoal tube method. The study used a well-characterized dynamic exposure system to closely duplicate actual environmental exposure conditions. The solvent vapor generation system provided accurate, stable, and reproducible atmospheres within the exposure chamber. This total system is recommended as a significant improvement over previously reported techniques. Temperature, relative humidity, barometric pressure and air velocity were monitored and held within a small range of variation. Desorption efficiencies were determined for each of the organic compounds on each of the sampling devices used. Statistical analysis determined monitor performance. All three manufacturer's monitors are demonstrated to be an acceptable alternative to the use of charcoal tubes. Several modifications are suggested concerning analysis of these devices. A problem in monitor performance is noted. A dynamic-flow chamber comparison of three passive organic vapor monitors with charcoal tubes under single and multiple solvent exposure conditions D.R. VOELTE and F.W, WEIR The University of Texas Health Science Center, School of Public Health. P.O. Box 20186, Houston, Texas 77025 introduction The Occupational Safety and Health Administration has required industry to monitor workers' exposures to various ^organic compounds and has established permissible levels to Rninimize possible ill-effects to workers exposed to these chemicals. These exposures are expressed as a time-weighted average (TWA). When these limits were first established, the National Institute for Occupational Safely and Health (NIOSH) recommended the collection of organic vapors on a charcoal tube using a calibrated pump. The charcoal in these tubes was then analyzed using gas chromatography. This tech nique has been extensively tested and reported in the litera ture, and has become the routine collection method for organic vapors/1'101 New methods of collection have been developed which employ passive organic vapor dosimeters. These monitors do not require a mechanical pump, but rather use the diffu sion principle as the driving force in sample collection. Abcor's Gasbadge, 3M's 3500 organic monitor, with draft shields, and DuPont's Pro-Tek, without any shield, use this principle. Previous studies to evaluate these dosimeters have been limited in scope because of one-to-one comparisons of char coal tubes to passive organic vapor monitors. The majority of studies have employed field monitoring*11,121 and have been of limited value because of many uncontrolled parame ters complicating interpretation. The few/ laboratory controlled studies have restricted themselves to the use of static*13,141 or quasi-dynamic<15) sys tems to expose these monitors. These exposure systems have several drawbacks which are minimized by the use of dynamic systems with larger exposure chambers and a flow through design which minimizes the "wall effects" found in many smaller static systems. A constant supply of organic vapors provides a stable concentration which is not reduced as the monitors collect the solvent. In static systems, this reduction can affect chamber concentration significantly at low concentrations. The study reported here compares the charcoal tube method to passive dosimeters of three major manufacturers: DuPont's Pro-Tek. Abcor's Gasbadge, and 3M's 3500 Organic Vapor Monitor; using a dynamic exposure system capable of generation of organic solvents over a wide range of concentrations. The resulting atmospheres are stable and reproducible. Other parameters known or suspected to interfere with these dosimeters, such as relative humidity, temperature, air velocity, and barometric pressure were monitored and remained within a small range of variation so as to minimize their effects. method.s and proced,ures OCC 8215 The conclusions and suggestions incorporated in this paper are solely hose of the above authors No part of this paper was edited or revised py any of the three corporations which participated in this study All three corporations were given a copy of the completed manu script and asked to present their opinions, if any, to be included in the "comments . . ". exposure chamber Exposures were performed in a 0.25M3 Rochester type dynamic flow inhalation chamber constructed of plexiglass. Units of this design are used almost universally for inhala tion toxicology studies. Characteristics of these chambers, in terms of uniformity of air flow and -contaminant concentra- Copwpbt 1961. Atnetictn Industrial Hygiene Association American Industrial Hygiene Association J0URNAI (42) 12/81 845 (ion throughout. are widely documented.'1 ' A vacuum em at the exhaust port created a negative pressure now cm. A Magnehelic gauge installed at this point measured the total flow rate in the chamber, which was controlled by a gate valve. The Magnehelic gauge was calibrated for flow using a 120 liter gas spirometer. A curve relating flow to gauge setting was prepared. This correlated significantly to the theoretical flows calculated for the various differential 3.05 m (10 ft) glass column, 2 mm ID, silane treated and packed with 10% FFAP on 80/100 mesh chromasorb W Any <'6,6 to.15) operating temperatures were set as fol lows: 160 C at the injection port. 220 C at the detector, and 100 C isothermal column operation. Chromatographic grade nitrogen was used as the carrier gas and the flow was set at 30 cc/min. A flame ionization detector was used. Maximum sensitivity of this detector was determined fol pressures. A chamber flow of 250 liters per minute (Lpm) lowing the manufacturer's recommended steady state w as chosen and the corresponding value was set and moni method. The settings determined were 16 pounds per square tored using the Magnehelic gauge. The chamber's relative inch (psi) for the hydrogen and 60 psi for the zero air. humidity and temperature were monitored with an Abbeon Samples were introduced into the instrument in two ways. Certified Hygrometer and temperature indicator. Liquid samples were injected following the method recom A 2.5 cm (I in) mesh wire was suspended 15.2 cm (6 in) mended by NIOSH.*1*101 A Glenco 10 pL syringe is flushed below the top of the chamber and the badges were suspended with carbon disulfide several times and 3 pL of carbon at eight selected positions 5.1 cm (2 in) below this screen. disulfide is drawn into the syringe. Then 0.2 pL of air is Thus, all badges to be tested were located on a cross- drawn into the syringe to be used as a marker. Finally, a 5 pL sectional plane approximately 10.2 cm (4 in) above the mid aliquot of sample is drawn into the syringe and the plunger is section of the chamber. Badges were placed a minimum of retracted further to prevent evaporation at the end of 15.2 cm (6 in) apart. In addition to the velocity of test the needle. atmosphere provided by the one change per minute (250 Air standards and chamber samples were collected with a Lpm) flow through the chamber, air movement within the Precision Sampling Pressure-Lok Series A-2 1.0 mL syringe. chamber was augmented using two 20.3 cm (8 in) fans installed in the upper dome of the chamber. Air velocities at Samples were collected with 30.5 cm (12 in) needles compat ible with this syringe. The plunger was slowly and com all badge positions were measured with a Kurtz air velocity pletely withdrawn and the syringe flushed. This step was meter and determined to be greater than 100 fpm at repeated, a sample taken, and the syringe valve was closed. each position. The needle was removed and a 5.1 cm (2 in) needle attached. A 30.5 cm (12 in) stainless steel needle was installed in the The valve was reopened, the volume was reduced to 1.0 mL, amber and, when attached to a series A-2 Precision Sam pling gas syringe, w'as capable of sampling the atmosphere at positions adjacent to the badges being exposed. the valve was closed and the plunger was depressed to 0.2 mL. The needle was then inserted through the septum of the gas chromatograph, the valve was opened and the plunger was simultaneously depressed. solvent generation system The solvent generation system employed the principle of a constant vapor concentration at a constant temperature and pressure. The constants for vapor pressure calculations were All determinations were made using the peak height as a direct indication of peak area due to the high resolution and narrow width of the peaks. obtained for the four solvents*181 and their saturated vapor validation of chamber atmosphere stability concentrations were determined at 0 Cand 760 mm Hg. By Exposures were conducted to test the temporal stability of knowing this, and setting the total exposure chamber flow at the exposure conditions. These exposures were monitored 250 Lpm. one may calculate the flow necessary for generat by discrete grab samples which were analyzed by gas chro ing 10 and 100 parts per million (ppm). This system was matography. The variability of chamber concentration for similar to that employed to make the NIOSH Proficiency each solvent at both low and high concentrations over six Analytical Testing Program samples.*191 These flows were hour intervals was determined. Mean concentrations and acheived using cylinders of purified nitrogen equipped with standard deviations were determined and are presented in 2-stage regulators to reduce the pressure to a moderate level. Table 1. The final flows were individually regulated with a blunt needle valve for each solvent and these flows were monitored by differential pressure manometers equipped with variable orifices and standard manometer fluid. The nitrogen was then directed into gas washing bottles containing each sol vent and the saturated vapor was directed into the intake port of the exposure chamber. The solvents in the gas wash ing bottles were maintained at a constant temperature with an ice-water bath at equilibrium. Figure J depicts the expo- Jre chamber and solvent generation system. Two preliminary studies were conducted to verify unifor mity of chamber concentrations and reconfirm that no sig nificant concentration gradients existed in the plane of exposure. For one of the solvents used in this study (trichlo roethylene), mean values were determined for 10 positions across a plane in the chamber, each position sampled 3 to 5 times. Relative results of these 10 values gave a mean of2650 ppm with a standard deviation of 2.9%. Using trichloroethy lene for a second series, four points (sampling each position 4 to 5 limes) gave a mean value of 3400 ppm with a standard analytical conditions deviation of 0.5%. This degree of uniformity has been a All analytic determinations were performed on a Perkin common experience of this laboratory with these chambers Elmer 3920 gas chromatograph equipped with a Supelco in past studies. OCC 8216 146 Am Ind Hf[ tooc J (4?) - December 1981 EXPOSURE SYSTEM Figure 1 -- Exposure system. OCC 8 2 1 7 Ifcrm/nif/on of desorption efficiencies Desorption efficiencies for the charcoal lubes and all three manufacturer's dosimeters followed the same basic steps outlined in NIOSH P and CAM 127 (subjecl to the modifi cations by each manufacturer). Placing the charcoal or collection element in a septum capped vial, the analyst injected the solvent(s) of interest onto the collection medium. The sample was allowed to stand overnight. The following day the appropriate amount of carbon disulfide solution was added, the sample gently agitated for 30 minutes and.an aliquot injected into a gas chromatograph. Standards and blanks were treated sim ilarly. Desorption efficiencies were determined using the equation: . area sample -- area blank desorption efficiency -- - ------- --------------7--------- area standard AH corrected sample values were divided by each of the standard values and these were averaged to give the most representative desorption efficiency for each solvent. Desorption of all solvents on all collection mediums was accomplished using a solution of 3% n-butanol in carbon disulfide. This is recommended by NIOSH and Abcor to improve the recovery of isopropanol.<2) All standards and samples w'ere run a minimum of five times each and averaged to accurately reflect the actual value. Desorption efficiencies for the charcoal tubes were per formed first. A 100 mg sample of charcoal from the charcoal tubes was placed into a 1.0 mL mini-vial and capped using microsep F-138 teflon'lined septa, the solvent was then injected into the charcoal. The amount used was determined "to represent that present in a 10-liter sample at a concentra tion equal to the federal standard."<)) Four samples and tw'o blanks were prepared for each solvent and allowed to stand overnight. These samples were desorbed by injecting 1.0 mL of the carbon disulfide solution into each sample. Duplicate standards were made for each solvent by injecting 10 times the amount used on the samples into 10 mL of car bon disulfide. The desorption efficiencies for each of the four solvents on the charcoal tubes were determined separately twice. A mix ture of these four solvents, in the same vdlume to volume proportions, was prepared and the amount used for the multiple solvent samples was equal to the sum of the volumes used for each of the previous single solvent samples. A statistical analysis of the desorption efficiencies deter mined by this method showed no difference between those determined one at a time.<6) Therefore, to conserve time and collection elements this later method was adopted for the rest of the determinations. Desorption efficiencies for Abcor were determined sim ilarly. The collection elements were placed in the vials pro vided by Abcor. These elements become overloaded at 15 mg of solvent so ] 3 ph of the solvent mix was used (11.4 mg) to prepare each sample. Private correspondence with Abcor recommended using 3.0 mL of the CSz solution for desorp tion.<21) Standards were prepared by injecting 43.3 pl_ of mix (13 X 10/3) inio 1(1 mL of CS2. Two standards and four samples were run. Desorption efficiencies for the DuPont badges were determined by placing the collection elements into 2.0 mL mini-vials. 26 pL of the solvent mix was used to prepare each sample. Three standards and four samples were run. 3M recommends that the CS2 solution be placed into their badges and samples be withdrawn directly. This method w'as difficult to reproduce and the desorption efficiencies deter mined were much higher than I00%due to the large amount of air space within the badge. To determine the desorption efficiencies for the 3M badge, the collection dement was removed and placed into a 2.0 mL mini-vial. 3M recom mends the amount of solvent used be determined by the amount of solvent present in a 7-liter sample at one-half the TLV. This was determined to be equivalent 10 9.1 pL of the solvent mixture. The lowest overload value reported was 8.5 mg for hexane and the total for the 9.1 pL was 7.9 mg. Standards were prepared by injecting 60.7 pL of the solvent mix into 10 mL CS2. A 1.5 mL aliquot of the CS2 solution was used to desorb the elements, as recommended by 3M. Three standards and three samples were run. For all analyses, the attenuation was adjusted for each compound to provide for a reasonable peak height. The desorption efficiencies w'hich were determined are presented in Table 11. exposure procedures This study consisted of sixteen exposures, each run included duplicate sampling using both charcoal tubes and each of the three brands of passive monitors. Eight positions were selected within the chamber at the cross-sectional plane described above. Constraints were imposed that badges should be separated from each other and the walls by 15.2 cm (6 in.) and air velocity should equal or exceed 0.508 m/s (100 fpm). This specific velocity was recommended in NIOSH's protocol for the evaluation of Compound Hexane Isopropanol Trichloroet hyle ne Toluene TABLE 1 Chamber Stability OCC 8218 Concentration (ppm) 17.0 i 0.5 (n=27) 13,6 0.6 |n=19) 14.3 04 (n=34) 13.9 0.7 <n=35) 91 2<n=35| 76 i 2 (n=35) 89 2<n=23) 102 2 (n=23) TABLE II Desorption Efficiencies for Various Organic Vapor Monitors Compound Charcoal Tube Passive Monitors DuPont Abcor 3M Hexane Isopropanol Trichloroethylene Toluene 1 02 0.98 1.03 1.01 1.02 0.71 0.96 0.94 1.01 0.93 1.02 1.01 0.96 085 095 0.96 ATM inA Uuo Accnr 1(4?) December. 1981 TABLE III Summary of Statistical Analysis Comparing Charcoal Tube vs. Passive Monitors* Intercept Estimated Standard Intercept (a) Deviation *It) Slope t1 Eitimated Standard Corrected Slope (b) Deviation t,r DuPont Hexane Isopropanol Trichloroethylene Toluene -0.136 -01179 0.1168 0.0159 O 137 00902 0.0412 0.0405 -1.00 -1.31 2.84n 0.39 1.0568 1.1292 0.9478 0.9610 0 0791 0.0584 0.0276 0.0262 0.72 2-21" -1.89 -1,49 0.903 0.952 0.984 0.986 Abcor Hexane Isopropanol Trichloroethylene Toluene -0.215 0.396 0.1474 0.0191 0.100 0.130 0.0520 0.0328 --2.14d 3.05e 2.83d 0.58 1.1210 08429 0.9140 0.9644 0.0602 0.0848 0.0357 0.0208 2.01 -1.85 -2.41D -1.71 0.953 0.852 0.976 0.992 3M Hexa ne Isopropanol Trichloroethylene Toluene -0.1514 -0.0437 0.0560 -0.0096 00900 0.0613 0.0303 0.0293 -1.68 -0.71 1.85 -0.33 1.0772 1.0009 0.9318 0.9811 0.0527 0.0367 0.0191 0.0190 t.46 0.02 --3.57e -0.99 0.956 0.975 0.992 0.993 20 20 20 20 18 18 18 18 20 20 20 20 *Data were analysed using the model log y = a + b log x c ti S O. a b- 1 S.D. b "Statistically significant at p < .05 ^Statistically significant at p < .01 OCC 8219 passive dosimeters.TM Manufacturers'criteria establishes a minimum velocity exposure well below the velocity used in this study.TM At two of the locations in the chamber, charcoal tubes were placed in a vertical position and tubing was run to the outside of the chamber to a vacuum pump. Critical orifices were made, calibrated, and installed in these lines to accu rately control the sampling rates of the charcoal tubes at 0.294 and 0.286 Lpm. A single charcoal tube was used at each position for the single solvent low concentration expo sures, two for the single solvent high concentration (three for isopropanol), and four for the mixed exposures. These char coal tubes were changed at regular intervals to prevent over loading and loss of sample. To ensure complete collection, four charcoal tubes were joined in series to sample during each of the two spiked exposures. Placement of the passive monitors at the other six posi tions was randomly determined prior to the first exposure and then held constant for subsequent exposures. The ratio nale for this was based on the previously determined uni formity of solvent concentration across the plane of exposure. The first four exposures were low concentration (approx imately 10 ppm), and of six hours duration; each exposure utilizing one of the four solvents from this study. To deter mine the required flows of organic solvents to the chamber necessary to achieve the desired concentrations, a series of standards was prepared. A curve was established which related concentration to peak height and the appropriate peak height representing a 10 ppm concentration was deter mined. Flows to the chamber were adjusted until the sample obtained duplicated this peak. The standards used for this series of exposures were made at 5, 10, and 15 ppm. These standards were prepared by injecting solvents into cali brated, sealed 20 L pyrex bottles. This container was fitted with a 30.5 cm (12 in) stainless steel needle. A 1.0 mL Series A-2 Precision gas sampling syringe was used to sample these standards. The second four exposures were high concentration (approximately 100 ppm), and of six hours duration; each exposure utilizing one of the four solvents from this study. The procedure was the same as above, using standards of 50 and 100 ppm. The third series consisted of six exposures. Each exposure was six hours in duration, with two solvents at the low' concentration and two solvents at the high concentration. All six possible combinations were used. Flows were set using the volume which best reflected the above single sol vent exposures on the differential orifice manometers. Standards were made at 10 and 100 ppm for this series. Two final exposures were conducted to evaluate the effect of a short interval, high solvent concentration on a generally low background concentration exposure sequence since it was considered that the time of the spike might influence the apparent performance of the passive monitors relative to the performance of the charcoal tubes. These exposures involved subjecting the monitors for six hours to all four solvents at a low background level on which a spiked concentration was imposed for 36 minutes. The first of these exposures Ameriran Industrial Hvpipnp Association JOURNAL M2) 12/81 149 involved spiking onr hour after the start of the run while the (second exposure involved spiking just prior to the last hour of the run. Solvent concentrations for both the background and spike were established solely by consideration of total monitor loading to preclude saturation. These concentra tions were in the range of 10 and 100 ppm, respectively. calculations Exposures were conducted in the four groups as mentioned in the exposure procedures section. The exposed charcoal tubes and monitors were removed immediately from the chamber after the six-hour exposure, sealed according to the appropriate manufacturer's instructions, and refrigerated at 2-4 C for up to two weeks prior to analysis. After each group of exposures had been completed, the samples were analyzed using the procedures previously described. Samples were analyzed three to five times each and averaged to reduce possible error, A series of standards was prepared in concentrations spanning the range of load ings for each monitor and analyzed each day with the samples. For each day of analysis, a curve relating chromato graphic peak height to concentration of the standards was determined by linear regression with the restriction the line must pass through the origin. There were several reasons for this restriction. Theoretically, the curve should pass through this point and the higher the concentration of the standards the more accurately the standard could be made. Also, when certain combinations of two solvents at high concentration and two at low concentration occurred, attenuation could not be adjusted to give a large peak for all four compounds because of dramatic shifting in the baseline. Peaks smaller in size but with a stable baseline were preferred. For smaller peaks, a small change in the y-intercept could cause a large change in the calculated value for the monitor. This limita tion was most pronounced for Abcor's and 3M's monitors because of the lower loadings and larger amounts of carbon disulfide used to desorb the samples. Calculations to deter mine average exposures in ppm were carried out using the equations supplied by each manufacturer. TABLE IV Comparison of Results by Chamber Position Compound Charcoal Tube DuPont Monitor 4>2a n p Value1' 6>3r n p Value " Hexane 6 10 .754 isopropanol 4 10 .754 Trichloroethylene 4 10 ,754 Toluene 6 10 .754 O 9 0.004 O 9 0 004 0 9 0.004 1 9 0.039 Number of exposures where the value at position 4 was greater tha n the value at position 2. BTwo-tailed sign test. Number of exposures where the value at position 6 was greater than the value at position 3 statistical analysts Separate comparison was made between the average of the charcoal tube values and each of the values from both of the passive monitors. Linear regression was used to compare the data. The model: log y = a+b log x was chosen, with y reflecting data from the charcoal tubes and x reflecting data from the passive monitors. As the concentration of a solvent increased the absolute variation also increased. By the use of logarithms, this phenomenon became more pronounced. Zero values were omitted for this analysis. The results of these calculations are shown in Table III. Separate compari sons were made between the average of the charcoal tube values and the higher value in each pair of values for the passive monitors and then repeated using the lower value of each pair. These sets of analyses gave results similar to the analysis encompassing all the data. Values for the charcoal tubes and DuPont's monitors were tested to determine if chamber position affected sampler performance. This determination was made using the sign test. The results of this are presented in Table IV, results Table 1 shows the results of testing the stability of the solvent atmospheres generated for the exposure chamber. Temperature, relative humidity and barometric pressure were monitored for the sixteen exposures in this study. Mean values for these chamber parameters were: tempera ture 23.2 C (with a standard deviation of I.l CJ, 46% relative humidity (with a standard deviation of 7%), and 752 mm Hg barometric pressure (with a standard deviation of 3 mm Hg). The results of determining desorption efficiencies are presented in Table II. Comparison of individual passive monitor performance to charcoal tube performance is pre sented in Table 111. Comparison of results by chamber posi tion are presented in Table IV. Data for the series of the sixteen exposures which were used in the statistical analysis of this paper can be found in Appendix "A" of the unpub lished master's thesis/21' discussion OCC 8220 Chamber atmospheres were monitored for six hours for each solvent at both low and high concentrations to deter mine the temporal stability of the system. The results arc presented in Table 1. Absolute variability increased as the concentration increased while relaiive variability remained within 5%. Results of the preliminary studies on the pla nar uniformity of atmospheres are indicative of the performance of these chambers, the design of which has been used rou tinely in toxicology investigations for over 30 years. The results demonstrated by this investigation show the feasibil ity and desirability of generating organic solvent atmo spheres for exposure chambers by the system described in this study. Desorption efficiencies were determined for each solvent for each monitoring device and are presented in Table 11. Desorption efficiencies determined on charcoal lubes were Am M Hyi teoc J (A3) December 1981 individually compared against those determined in a matrix and no significant difference was found. This finding had been reported earlier.161 The desorption efficiencies for all the passive monitors were determined for all sol vents simultaneoush. Desorption efficiencies for DuPont w'ere run twice to confirm the low desorption efficiency determined for iso propanol. Seventy-one percent was determined each time and was accepted because of its reproducibility. Determination of desorption efficiencies for the 3 M moni tors was attempted twice using the 3M recommended method. Results were consistently above 100% recovery. No problems were experienced when the charcoal pads were removed from the badges and analyzed in 2 mL vials. In cases where there are solvents at both high and low concentrations, it is difficult to change attenuation on the gas chromatograph to give a large peak due to dramatic shifting in the baseline. This limitation was most pro nounced for Abcor's and 3M's monitors due to the lower loadings and larger amounts of carbon disulfide used. Load ings, because of higher concentrations of other solvents, could not be increased without overloading the monitors. Since the peaks for some of the compounds were small, a change in the y-intercept could cause a large change in the value calculated for the monitor. Therefore, the standard curves were calculated with the restriction that the curve pass through the origin. Theoretically, the line should pass through this point. In addition, standards prepared at low concentrations could not be made with as much accuracy as those at higher concentrations. This made it difficult to determine where the curve should pass at the lower end of these curves. Because of the problems encountered with solvents at these lower concentrations it is suggested that smaller amounts of carbon disulfide be used for desorption. The slight increase in desorption efficiency does not appear to outweigh the disadvantage of smaller peaks. Difficulties were also encountered at lower concentrations with the quantification of isopropanol due to a severe inter ference by carbon disulfide which made baseline determina tions difficult. If this problem is expected, analysis by a different chromatographic column, which will give better resolution, is recommended. Exposures within the chamber were all conducted with air velocities in excess of 0.508 m/s (100 fpm) as is recom mended by NIOSH. DuPont stated that for the testing of their Pro-Tek organic vapor monitors, their badges were more sensitive to inadequate face velocities than Abcor's or 3M's monitors.*221 For this reason, DuPont's badges were placed at the two positions with the highest velocity. One position averaged 0.762 m/s (150 fpm) and the other posi tion averaged 0.635 m/s (125 fpm). No difference was expected since DuPont stated these monitors were cali brated to accurately measure between 0.169 m/s and 2.032 m/s (35 to 400 fpm). After analysis of the first four expo sures, a noticable difference in values was observed. Posi tions of the DuPont monitors were recorded for the last Amencan Industrial Hygiene Association JOURNAL (42) 12/81 twelve exposures. Results by position were compared for charcoal tuhes and the DuPont monitors. These results are presented in Table IV. It is clear that there is no significant difference in positions for the charcoal tubes while there is a significant difference in position demonstrated for the DuPont monitors. It appears that these monitors are sensi tive to differences in velocities of the surrounding air since all other variables w'ere kept constant at both positions. These monitors, unlike Abcor's and 3M's monitors, do not have a draft shield. This could explain the difference in monitor performance. It is also possible that chamber concentration at these locations varied since they were not monitored during actual exposures. Data previously presented on uni formity of solvent concentration within the chamber mini mize this as a possible explanation. It should be emphasized that positions were not recorded for the Abcor and 3M monitors and therfore similar comparisons could not be made. Comparison of monitor performance to charcoal tube performance is the most widely recognized method for vali dation of passive monitors. Comparison was made using the model: log y = a+b log x w'here the y value was the average value for the charcoal tubes w'hich was paired against each of the values calculated from the passive monitors for the same exposure. This series is summarized in Table III. Compari son was repeated using the average value for the charcoal tubes and the higher value in each pair for each organic monitor. Comparison was made substituting the lower values for the higher. Little difference was noted for these three series of analysis which demonstrated both organic vapor monitors and charcoal tubes would give a good representation of the exposure. Table III shows that all three brands of passive monitors should be considered an accept able alternative to the recognized charcoal tube method. All three companies' monitors had y-intercepts close to the origin. For the determination of higher concentrations closer to the TWA's of these compounds, the slope of the regression line becomes increasingly important. While all three companies' monitors have fairly good correlations with the results from the charcoal tubes, 3M's monitor gave the best slope in two out of four cases and showed the smallest variation every time as is demonstrated by examina tion of the standard deviation. 3M's monitor did not per form as well as DuPont's monitor for trichloroethylene and hexane. A poor correlation between charcoal tubes and Abcor's monitors pertaining to isopropanol could be due to problems with baseline determination discussed earlier. conclusions occ g221 1. Under conditions similar to those of this study, DuPont's, Abcor's, and 3M's passive organic vapor monitors are an acceptable alternate to the charcoal tube method for assessment of a worker's exposure to organic solvents, as is demonstrated by the good correlation between each monitor with the results obtained by the charcoal tubes. 2. Significant differences between monitor perfor mance were noted for DuPont's monitors. Sensitiv- 851 ity to velocities surrounding the monitor is suspected . as the reason. When isopropanol is monitored at low concentra tions. especially in the presence of high concentra tions of other compounds, selection of chromato graphic columns becomes important if one wishes to minimize interference by carbon disulfide. 4. Analysis of 3M's monitors is improved by removing the charcoal pad and placing it into a 2 mL septum capped vial. 5. Desorption efficiencies can be determined for sev eral solvents simultaneously with no significant dif ference over determination of each solvent individu ally, provided the charcoal device is not over-loaded with solvents. 6. The exposure system, including the organic solvent generation system described in this paper, is recom mended as a significant improvement over pre viously reported exposure techniques for the deter mination of monitor performance. It should be emphasized that this study was a laboratory controlled experiment which, while examining several important parameters, kept several other equally important parameters constant. The conclusions drawn in this paper should only be considered valid when the conditions of exposure have been met. This is the first of what should series of studies which need to be conducted to ^Hfy whether these conclusions can be extended to conditions such as elevated relative humidity and extremes in temperature. references 1. NIOSH: Manual of Analytical Methods, 2nd Ed.: P and CAM 127, Organic Solvents in Air, DHEW (NIOSH) Publication No. 77-157, Cincinnati, OH (1977). 2. NIOSH: Manual of Analytical Methods, 2nd Ed : Method S65, Isopropyl Alcohol. DHEW (NIOSH) Publication No. 77157, Cincinnati, OH (1977). 3. NIOSH: Manual of Analytical Methods, 2nd Ed.: Method S90, Hexane. DHEW (NIOSH) Publication No. 77-157, Cincinnati, OH (1977). 4. NIOSH: Manual of Analytical Methods. 2nd Ed.. Method S336, Trichloroethylene. DHEW (NIOSH) Publication No. 77157. Cincinnati. OH (1977). 5. NIOSH: Manual of Analytical Methods, 2nd Ed.: Method S343, Toluene. DHEW (NIOSH) Publication No. 77-157, Cincinnati, OH (1977). 6. White, L.D.. D.G. Taylor, P.A. Mauer and R.E. Kupel: A Convenient Optimized Method tor the Analysis of Selected Solvent Vapors in the Industrial Atmosphere. Am. Ind. Hyg. Assoc. J. 3 7:225-232 (1970). 7. Mueller, F.X. and J.A. Miller: Determination of Airborne Organic Vapor Mixtures using Charcoal Tubes. Am. Ind. Hyg. Assoc. J 40 380-386 (1979). 8. Saalweechter, A.T., C.S. McCammon. Jr.. C.P. Roper and K.S. Carlberg: Performance Testing of the NIOSH Char coal Tube Technique for the Determination of Air Concentra tions of Organic Vapors. Am. Ind. Hyg. Assoc. J. 33:476- 486(1977). 9. Larkin. R.L., J.V. Crable, L.R. Catlett and M.J. Seymour: Collaborative Testing of a Gas Chromatographic Charcoal Tube Method for Seven Organic Solvents. Am. Ind. Hyg. Assoc. J 33:543-553 (1977). 10. Mindrup, R.F.: Determination of Organic Vapors in the Industrial Atmosphere. Bulletin 769A, Supelco, Inc. Bellefonte, PA (1977) 11. Boeniger, M.F., D.D. Zaebst, H.R. Ludwig, M.S. Crandall and P. Vongrongsemon: A Field Comparison of Two Passive Organic Vapor Monitors with Charcoal Tubes Under Singular and Multiple Exposure Conditions. Presented at the 19th Annual American Industrial Hygiene Conference - Chicago (May, 1979). 12. Mazur, J.F., G.E. Podolsk, G.G. Esposito, D.S. Rinehart and R.E. Glenn: Evaluation of a Passive Dosimeter for Col lection of 2-bromo-2-chloro-1,1,1-trifluoroethane and 2chlor - 1,1,2-trifluoroethyl difluoromethyl ether in Hospital Operating Rooms. Presented at the 19th Annual American Industrial Hygiene Conference - Chicago (May. 1979). 13. Tompkins, F.C., Jr. and R.L. Goldsmith: A New Personal Dosimeter for the Monitoring of Industrial Pollutants. Am. Ind. Hyg. Assoc. J. 38:371-377 (1977). 14. Bamberger, R.L.. G.G. Esposito. B.W. Jacobs. G.E. Podolak and J.F, Mazur: A New Personal Sampler for Organic Vapors. Am. Ind. Hyg. Assoc. J. 39:701-708(1978). 15. Calvo, D.J.: Laboratory Performance of Passive Personal Samplers for Organic Vapors in the Presence of AdsorptivelyCompeting Solvents. Presented at the 19th Annual American Industrial Hygiene Conference - Chicago (May, 1979). 1E. National Academy of Sciences: Principles and Procedures for Evaluating the Toxicity of Household Substances, pp. 61-69. Washington, D C (1977) 17. Silver. S.D.: Constant Flow Gassing Chambers: Principles Influencing Design and Operation. J. Lab. Clin. Med. 31:1153-1161 (1946) 18. Nelson, G.O.: Controlled Test Atmospheres Principles and Techniques, pp. 147, 217-219, Ann Arbor Science Publish ers. Ann Arbor (1971), 19. HagmBnn, E.L.: Generation of Standard Reference Organic Solvent Samples by the Vapor Saturation Method. Presented at the 19th Annual American Industrial Hygiene Conference - Chicago (May, 1979). 20. NIOSH: Contract 210-78-0115. 21. Voelte, D.R.: A Dynamic-flow Chamber Comparison of Three Passive Organic Vapor Monitors with Charcoal Tubes under Single and Multiple Solvent Exposure Conditions. Unpublished Master's Thesis, The University of Texas School of Public Health, Houston. Texas (1980). 22. E.l. DuPont de Nemours and Company. Inc.: Technical Bulletin No. 1; Laboratory and Field Testing of the Organic Vapor G-AA Badge. Wilmington, Delaware (1979). OCC 8222 is: Am. Ind Hyg Assoc. J (42) December, 1981 ^mments . . . A dynamic flow chamber comparison of three passive organic vapor monitors with charcoal tubes under single and multiple solvent exposure conditions Thank you for the opportunity to review and comment on "A dynamic flow chamber comparison of three passive organic vapor monitors with charcoal tubes under single and multiple solvent exposure conditions," by D.R. Voelte and F.W. Weir. We find it, in general, technically sound, and offer the following comments: 1. In calibrating their gas chromatograph, the authors chose to draw all standard curves as linear and through the origin. In our experience, solvent or baseline interferences often have yielded non-zero intercepts for multipoint linear calibration curves, especially at low analyte levels when a flame ioniza tion detector is used. Such interferences are sus pected in the low level calibration for isopropanol; it is our belief that the standard curves should not have been forced through the origin. 2. The authors reported severe baseline jumps when making large attenuation changes during a run. This problem, if not associated with detector or injector contamination, can often be minimized by employ ing dual column differential compensation. 3. The authors concluded, based on statistical argu ments (Table 111), that the 3M monitor was some what superior in performance to the Gasbadge" dosimeter. As evidenced by the slope data for mate rials other than isopropanol, the 3M monitor showed an average relative standard deviation (RSD) of 2,99) while the Gasbadge averaged 3,89) RSD. Since the RSD for repeat injections of identical GC standard is approximately 2.09) under idea) con ditions. we feel that the deviations for the two dosimeters agree within the systematic error of the analytical procedure. Because of baseline problems, the isopropanol data should not be considered in a side-by-side comparison of the two draftshield type dosimeters. 4. We agree with the authors that based on their data, all 3 dosimeters tested showed acceptable accuracy. Again, we thank you for the opportunity to present our comments on this work, Michael S. Young Project Chemist Jamie P. Monat, Ph.D. Manager, Environmental Engineering Department Walden Division of Abcor Inc. We have reviewed the final draft of "A Dynamic Flow Chamber Comparison of Three Passive Organic Vapor Monitors with Charcoal Tubes Under Single and Multiple Exposure Conditions," by D.R. Voelte and F.W. Weir and have prepared the following comments for concur rent publication. Du Pont is pleased to see another report on the overall good performance of passive dosimeters and appreciates the opportunity to comment on the results obtained by Prof. Weir and Mr. D.R. Voelte. The points we feel are important for the reader to consider are. I. Du Pont has thoroughly tested the GAA Organic Vapor Monitoring Badges under various conditions prior to commercialization in chambers specifically designed to minimize concentration and flow gra dients as well as insidious wall effects. Our experi mental data presented below show no face velocity effects over the range of 32.5 to 325 feet/minute verifying the theoretical concepts used in initial badge design. The data is presented in sampling rate (DA/L) (cm3/minute) versus face velocity over the concentration range of3.2 to 35.8 ppm benzene in air. Test No. 1 2 3 A 5 6 ppm CfHr, 35 8 35,8 6.7 67 32 3.2 Face Vel. (ft/min) 32.5 32.5 162.5 162 5 325 0 325.0 Sampling Time (DA/L) (cm'Vmin) 93 4 B3.4 88.6 85.5 97.3 , 92 8 X = 90.2 S.D = 5.25 CV.= 0.0582 2. We agree with other statements made by the authors, especially concerning the apparent face velocity observed with Du Pont badges. They did not moni tor chamber concentrations at these locations as diligently as at the 3M and Abcor locations. Addi tional experiments in which badges were randomly distributed among the test positions would be helpful. 3. A recent article in the A1HA Journal [Koizumi. A. and M. lkeda, American Industrial Hygiene Associ ation Journal 42:417-425 (1981)] emphasizes the need for more elaborate controls, as well as the use of inert chamber construction, to minimize concen tration gradients in the chamber type used by Voelte and Weir. Clairbourne D. Smith Manager, Applied Technology Division Du Pont Company OCC 8223 farember. 3981 The conclusions of "A Dynamic Flow Chamber Com parison of Three Passive Organic Vapor Monitors with Charcoal Tubes Under Single and Multiple Exposure Conditions." by D.R. Voelte and F.W. Weir, appear to establish the validity of passive dosimetry as an alterna tive to the charcoal tube method. The possible problems mentioned in the study as they pertain to the GASBADGE are currently under investigation. In addition, the appli cation of the GASBADGE to a wider range of solvents is under consideration. Ford Stoll, Jr. National Mine Service Company author's reply . . . The following are the responses to comments of Abcor and DuPont regarding the Voelte-Weir Study: Abcor: It is possible that the results of isopropanol on the Abcor badge may have been improved if we had not used the restriction that the calibration curve should go through the origin. Improvements in determinations of monitor perfor mance could also be improved by: A. Increasing the amount of isopropanol collected, when possible, but avoid overloading the collec tion element. B. Decreasing the amount of carbon disulfide used to desorb the collection element. C. Decrease gas chromatograph interferences as dis cussed below. These three steps would improve the analytical results and shift the determinations further from the origin, thus min imizing its effect. We agree that the suggested use of dual column dif ferential compensation would have reduced the problems encountered when analyzing foT low concentrations of isopropanol and is probably preferrable to the use of an alter nate packed column. Our paper states all three monitors are acceptable as an alternative to the use of charcoal tubes. Each company's monitor has its particular performance characteristics such as rate of collection and amount of solvent used to desorb badges. The major problem with the Abcor badge was due to the small amount of isopropanol collected and the high dilution due to the large amount of carbon disulfide used to desorb the collection element. Under the conditions of this study, the Abcor badge was the most difficult to use to determine low level concentrations of isopropanol when other solvents are present at higher levels. Dupont: A major purpose in conducting our investigation was to demonstrate the relative utility of passive dosimeters as compared to charcoal tubes using conventional inhalation toxicology methodology that should reflect probable use conditions. Our exposure chambers, used in the manner described in our paper, are well characterized regarding uniformity of concentrations throughout the exposure zone. They represent a design that has been widely accepted for use in this field. The Koizumi and Ikeda Study(AIHA 42:417-425 (1981)) referred to in the DuPont comments utilized a chamber similar to the one used in our study. Although they used stainless steel for construction they did not discount the utility of plexiglass as suggested by the DuPont comments. Further, Koizumi and Ikeda modified their inlet port to create laminar flow through their chamber for the special purposes of their study. Our chamber inlet was similar to the original widely accepted "New York University type". This inlet design provides very uniform mixing of influent gas streams before entry into the exposure zone of the chamber. Fans were added in our chamber solely for the purpose of increasing general air velocity in an effort to more closely simulate conditions expected during industrial use of the monitors. Unpublished observations from our laboratory on per formance of these passive dosimeters utilizing equipment and conditions similar to those reported above by DuPont concur with their results. We have no argument regarding DuPont's results. However, we continue to think that the exposure chambers and circumstances reported in our study reflect probable industrial use conditions more reliably than does the very specialized equipment, providing precisely defined laminar flow velocities presented in a uniform direc tion to the face of the subject badges, used as described by DuPont in their investigation. It should be noted that these DuPont data represent the first publicly presented to support their claim that face veloc ity does not affect badge performance. While our paper suggests that face velocity may affect badge performance, wx do recommend that further work is needed to explore the problem. We hope that independent sources will be able to resolve this issue. In any event, our basic position remains that, even if sampling rates vary somewhat with face velocity as sug gested by our data, the DuPont badge should be considered to be an acceptable alternative to sampling with charcoal tubes, at least over the range of conditions used in this study. We appreciate comments from the suppliers of these mon itors as well as their participation in this study. It is note worthy that all parties have indicated general agreement concerning our results. Francis W. Weir David R. Voelte OCC 8224 A passive dosimeter-type personal monitor tor vinyl chloride has undergone extensive field testing. Collaborative studies by a number of laboratories confirm the accuracy, reliability, convenience and general acceptability of personal monitors utilizing gas permeation for sample collection and quantification. Data are generated as timeweighted averages and response is linear from 5 ppb to 50 ppm. The monitors which weigh only 35 g are unaffected by variations in environmental conditions. Field tests of a permeation-type personal monitor for vinyl chloride PHILIP W. WEST, Ph D, D.Sc. and KENNETH D. REISZNER, Ph D Environmental Sciences Institute, Department of Chemistry, Louisiana Slate University, Baton Rouge, LA 70803 introduction The analytic process begins with a need, whether real or imagined. The analysis itself may involve a number of steps including sampling, sample stabilization, preparation, concentration, separations and finally, the desired determina tion or measurement. The analytic process also involves data processing and, very possibly, validation. Unfortunately, measurement is often considered to be synonymous with analysis and much of the emphasis in the past has been on the measurement step under the assumption that this was the most critical part of the analysis. In reality, however, sampling is often the most difficult and subject to the most error. For industrial hygiene studies the sampling of the workplace atmosphere is of utmost importance. It is especially important that a convenient, reliable method for personal monitoring be used so that valid information be provided for the protection of the individual and for the extension of factual knowledge required in the evaluation of hazards. In a general sense, sampling can be classified as either active or passive. The sampling of atmospheres has most generally been accomplished by means of some mechanical or active process, such as the use of a pump for pulling the sample through some metering device and a collection medium such as an adsorber or absorber. Although such active sampling techniques are standard, they do present certain difficulties. The use of motors, pumps, power sources and collectors when incorporated into personal monitoring devices tend to present a cumbersome and often unreliable sampling mechanism. Such mechanical devices tend to break down or wear out and they are relatively expensive. The recent introduction of passive sampling by means of permeation offers a simple, reliable, convenient and low-cost alternative. OSHA regulations are based primarily on NIOSH recommendations. For gaseous hazards such as vinyl chloride, the collection and stabilization by charcoal tubes has been specified. No specifications have been promulgated regarding motors, pumps, metering devices or other components that would normally be considered integral parts of personal monitors. Thus the collection of samples by means of permeation should be considered valid provided the quantification is accurate and falls within specified confidence limits. The device for the personal monitoring of vinyl chloride employs charcoal as recom mended by N10SH. The measurement step, likewise, is the same as that already in use whereby the collected sample on charcoal can be eluted using carbon disulfide and the amount determined by conventional gas chromato graphy. Also, the personal monitor meets requirements because laboratory and field tests show accuracies achieved with permeation are well within specified limits. Because the unique and critical feature of the permeation device for vinyl chloride is the permeation process itself, a brief summary describing the process is presented. The terms permeation and diffusion are familiar. Although there are similarities between American Industrial Hygiene Association JOURNAL (39) 8/78 645 OCC 8225 permeation and diffusion, there are subtle but at times important differences. Basically, diffusion represents the passage of molecules through holes in a discrete barrier whereby turbulence is minimized. Beyond the barrier or drafi shield a stagnant air layer prorides a means for mass transfer to a collecting medium with quantification of the transport following Pick's Law of Diffusion. N = --DA(dc dx) where. N = rate of diffusive transport, moles, sec D = diffusivity of contaminant. cm` sec A = area of diffusion path, cm* x = length of diffusion path, cm c = concentration of contaminant, moles/cm3 The Walden "GasBadge" utilizes the diffusion principle."1 For permeation, a barrier to ambient atmospheres is also involved but its function is to serve in the direct quantification of contaminant species. In this case there are no holes in the barrier. Instead, a polymeric membrane is utilized and gaseous contaminants contact the membrane and dissolve, permeate and thus are transported through the membrane to a collection and stabilization medium such as charcoal. The permeation constant, k, for the membrane used and for a given contaminant permits the determination of the time-weightedaverage concentration for the contaminants, C = wk/t Consideration of malhematic expressions relating to diffusion and permeation fails to disclose effects that might result from non-ideal parameters. For personal monitors, for example, what is the effect of movement relating the atmosphere being sampled to the collecting interface? What is the effect of humidity? Of temperature? Do particulates or various coexisting gases have effects? In our studies, both in the laboratory and in the field, the permeation approach has proven to be the method of choice. Air movement, or lack of it, was of no significance nor were changes in humidity nor was the coexistance of various gaseous or particulate species. Permeation rates were known to vary according to temperature but this problem was negated by use of special membranes having properties that were altered but little by varying temperatures. For example, the vinyl chloride monitor exhibited essentially no temperature dependence over the range of zero to 40 C. experimental permeation device The permeation-type personal monitor used for the evaluation studies was the same as that described previously'3' with only minor modifications (Figure 1). It consisted of a hollowed out aluminum plate which served as a reservoir for activated charcoal, a silicone permeable membrane for quantification of gas collection, and a front grid which protected the membrane from physical abuse. where, C = concentration, ppm w = weight of contaminant, pg t = exposure time, hrs The permeation constant is first determined by calibration using appropriate contaminant concentrations in an exposure chamber. The first use of permeation for sample collection was for the determination of sulfur dioxide in ambient air.'2' Us use in personal monitoring for vinyl chloride exposures has been described recently'3' and a commercially produced dosimeter, the MINIMONITOR, is now available (REAL Inc., Box 3341, Baton Rouge, LA 70821). Figure 1 -- Permeation personal monitor. 646 4m Ini Hyg Assoc J f39) August 197 occ 8226 TABLE Preliminary Field Evaluation (4hr TWA) Vinyl Chloride, ppm Sample 1 2 3 4 s 6 7 Conventional Monitor (ppm VCI) 1.00 010 0.12 0.12 034 0,04 <002 ASTM Monitor (ppm VCI) 1.00 012 0,14 0.13 037 0 05 < 0.02 Permeation Monitor (ppm VCI) MS 019 0 10 0.17 051 0 07 <0.02 TABLE II Contributed Field Data. USA Vimyl Chloride, ppm Temp C (6F| % Humidity Permeation Device Mo 2 Mo 4 Sipin Pump Sampler 29 I84J/80 26 (781/87 24 (76|/91 29 (85|/74 31 (87|/67 24 (761/71 * . 24 (761/71 23 (731/73* Oil 0.09 0 44 0.32 0.29 1.28 0.11 0.32 0.08 0,15 0 12 0.47 0.35 033 0 36 1.80 *7 hr exposure in fined local ion (VCM Lab) PD adjacent to sampler carbon lube Calibration of the monitors was done by the cooperating laboratories in accordance with their respective preferences. Permeation tubes and standard gas mixtures were used, the choice being a matter of company practice. The activated charcoal used for the sample adsorption in each case was similar to that used in the pump-charcoal tube monitors used for comparison. The analytic finish in all cases was by means of standard gas chromatography following sample desorption using carbon disulfide. Calibration, therefore, consisted of exposing the monitors in a standard gas atmosphere containing vinyl chloride and determining the weight of material collected over the exposure period, k = ct/w where, k = device permeation constant c = known concentration of vinyl chloride t = time of exposure w = weight of vinyl chloride adsorbed validation A test program was organized to determine the characteristics of a badge-type persona! monitor for vinyl chloride. The original laboratory studies were backed up with field studies. Both the laboratory and field work have now been extended by independent investigations carried out in a number of plants and laboratories in the United Kingdom, as well as in Canada and the United States. The findings are presented here without identifying the cooperating individuals and laboratories. The data presented were contributed as a means of furthering the protection of colleagues throughout the world who might be exposed to potentially hazardous concentrations of toxic materials such as vinyl chloride. A local manufacturer of vinyl chloride contributed data from a preliminary field evaluation (Table I) in which ASTM and conventional pump monitors were compared with permeation-type monitors. The results were obviously good. Further studies were made under differing conditions of temperature and humidity. As shown in Table II, values obtained on days with temperatures ranging from 22.8 to 30.6 C and humidities of 67 to 91% gave excellent agreement and confirmed laboratory findings that there was essentially no temperature effect over a range of zero to 40C nor any due to humidity over the range of 100% to less than 10%. An additional set of data presented in Table 111 simply confirms those given in Table 1. The two studies were made at different times and under somewhat different conditions. A second company located in the Gulf Coast area submitted the data shown in Table IV. Again, the results confirm the reliability of the permeation approach for sample collection. It is of interest to note that all data presented in the four tables were generated in a very complex industrial region where a wide variety of organic and inorganic manufacturing ot processing operations were always in progress. Collaborative studies conducted in the United Kingdom were initiated by the committee on vinyl chloride and were performed in a number American Industrial Hygiene Association JOURNAL (39) 8/78 6A7 OCC 8227 TABLE III Vinyl Chloride Personal Monitor Data Vmyl Chlotide (ppm] Sample Conventional Monitor Permeation Monitor Monitor Number 2 0 83 0 96 2 3 0 10 0 17 3 5 0 05 0 16 2 6 0 10 0 15 3 7 0 07 0 12. 0 11 2: 5 B 0 07 0 05; 0 08 3. A 9 0 50 0.51; 049 2: 5 10 041 0 42. 0 48 3. 4 11 0 02 < 0 OS; < 0 05 2; 3 12 0.88 0.92. 0.97 4: 5 Note Sample 1 gave the following results' 6.9 ppm by conventional end 8 9 ppm by permeation -monitor (monitor no. 1) and Sample 4 gave 3.6 ppm by conventional and 6.1 ppm by permeation monitor (monitor no. 1). Due to the difference in the results, they are not included m the Table (difference maybe due to a calibralon error) Date 6/16/76'1' 6/1 6/17 6/21 6/21 6/24 6/25 6/28 6/28 6/29 6/29 6/30 6/30 7/1 7/1 7/2" 7/2 7/6 7/6 7/7 7/7 7/8 7/8 7/9 7/12 7/12 7/13 7/14 7/14 7/15 7/15 7/16 7/16 TABLE IV Contributed Data, USA - No. 2 Ambient Temp CC (F) 28 (83) 28 (83) 32 (90) 32 (90) 29 (85) 31 (88) 27 (80) 30 (86) - 29 (84) 29 (84) 26 (78) 26 (78) 24 (76) 28 (83) 29 (85) 29 (85) 31 (87) 31 (87) - Relative Humidity, % 86 86 73 82 82 70 60 73 61 - 80 80 87 87 91 72 74 74 67 67 Vinyl Chloride, ppm Permeation1*' Device No 2 No 4 Pump Sampler 1.31 0 12 0 12 0.59 0 97 0 40 0 95 0 84 0.18 0,27 1,40 041 063 0 10 0,11 0 16 0 90 017 1 18 0 11 Oil oil 0 15 0 09 0 09 025 023 047 0 44 0 99 032 0.36 0 09 1.01 1.07 0.12 0.23 0.34 0.50 0.49 0.38 0.82 0.16 0.30 1.75 0.33 0.65 0 05 0.06 Oil 0 90 0 08 0.23 0.08 0.08 0 16 0 19 0 12 0.25 048 0 53 047 0 86 035 0.35 010 0 86 648 Am fad Hyg Asm J (39) August. 1978 OCC 8228 7/19 7/20* 7/20* 7/26* 7/26* 7/27* - - 24 (76) 24 (76) 23 (73) 0 35 0 69 - on 0.12 - 0 13 0 12 71 0.32 0.33 71 0.29 0,36 73 1.28 1.80 n'P0 placed on one side of collar, pump on other. UlPD placed adjacent to pump on same side of collar '''Monitors were calibrated at LSU *7 hr exposure in fixed location (VMC Lab.). PD adjacent to sampler carbon tube. TABLE V Contributed Data, United Kingdom VCM present, ppm v/v 1.5 1.9 3.7 3.9 39 4.0 5.7 7.6 13 9 VCM concentration found--ppm v/v ABco 1.4 21 3.4 3.9 4.0 39 5.7 7.9 14.3 14 2.2 3.2 4,0 3.9 3.8 5.8 78 14.1 1.3 2.1 3.6 4.1 40 3.7 5.9 7.6 13.2 1.5 2.1 3.3 38 3.7 3.9 5.3 7.6 13 1 {laboratories. The results presented in Table V give replicate values obtained using four permeation devices. As a matter of interest, a sample calibration graph submitted by the U. K. committee is shown in Figure 2, (also see Table VI), Of special significance are the conclusions and recommendations which are quoted as follows: conclusions "Convention would require the laboratory work recorded here to precede plant trials. The results from the plant trials have already been acknowledged to be encouraging; the calibration series now completed further justifies the faith inspired by the badges from the outset. A fair spread of time/concentration combinations has been covered, without revealing any weakness likely to arise in the conditions met in personal monitoring. We feel curiosity, rather than concern, that the permeation constant, K, found here may differ from those established elsewhere. recommendations The Louisiana badge and the Century Systems programed thermal desorber have undergone independent evaluation, with favourable results. There is no reason to be apprehensive about using the two together, but a limited series of laboratory trials should be run when the Automatic Injection valve becomes available for the P-D. This system promises to be the best and most economic for future persona) and similar monitoring." discussions and conclusions The validation studies contributed by impartial industrial laboratories have confirmed the accuracy and reliability of the permeation approach for personal monitoring. The permeation-type monitors showed a small positive bias in the field studies which did not TABLE VI Plant Trials, United Kingdom Date 5/4/76 5/6 5/7 5/8 5/9 5/10 5/10 5/11 5/11 5/12 5/12 5/13 5/13 5/14 5/14 5/17 5/18 5/18 5/18 6/22 6/22 6/23 6/23 6/25 6/25 6. 28 Pump VCM. ppm 2 96 2 16 2 32 2 44 pump broke 2 72 8 36 8 21 2.11 3 48 5,85 4 92 1 48 16 7 163 5 97 8 74 6.99 4 54 14 4 41 164 pump broke 62 12 4 85 Permeation VCM, ppm 3 78 2 25 2.33 2 90 8 40 3 11 1091 10 11 2 59 3.77 11.00 5 14 2 27 21 0 15 8 7.54 9 84 7.36 4 76 12,1 39 194 7.50 65 14 5 91 American Industrial Hygiene Association JOURNAL (39) 8/78 649 OCC 8229 B' LOUISIANA BUTTON CALIBRATION GRAPH Microliters vc/Bulton Figure 2 -- Louisiana button calibration graph. appear in laboratory evaluations. The only explanation proposed for the lower results obtained in the field with pump-type monitors was the possibility that battery driven motors were used and battery fatigue might have caused smaller than expected samples to result. There were no failures nor malfunctions reported in the use of the permeation-type monitors. This was in contrast to the experiences reported with the conventional monitors. The latter were beset with pump failures as well as occasional motor and battery problems. In addition to the low cost and reliability of the permeation approach, the great advantage of convenience made the permeation-type monitors completely acceptable to the wearers as contrasted to the objectionable discomfort reported by personnel forced to wear conventional equipment. A final matter of interest is that of cost. The permeation approach makes it possible to provide monitors which are essentially indestructible and which cost less than $50 each. acknowledgements We wish to acknowledge the partial support of the National Institute for Occupational Safety and Health, USPH Grant R10H-00666A. We are indebted, also, to the many individuals and industrial companies that advised and collaborated in the test program. references 1. Tompkins, F. C. and R. C. Goldsmith: A New Personal Dosimeter for the Monitoring of Industrial Pollutants. Am, Ind. Hyg. Assoc. J. 38:371 (1977). 2. Reiszner, K. D. and P. W. West: Collection and Determination of Sulfur Dioxide Incorporating Permeation and West-Gaeke Procedure. Env Sci, Tech 7 526(1973). 3 Nelms. L. H.. K. D. Reiszner Bnd P. W. West: Personal Vinyl Chloride Monitoring Device with Permeation Technique for Sampling. Anal. Chem. 49:994 (1977). Accepted Jan 5. 1978 6 SO Am. Ind Hyg. Assoc. J139] Aujusl. 1978 OCC 8230 Reprinted from American Laboratory, July 1980 By Philip W. West Passive monitoring of personal exposures to gaseous toxins he benefits the chemical age has brought to tionally valuable. Thumanity would not have been imagined Some criteria for ideal monitors are obvious. even fifty years ago. However, we have come Reliability and convenience head the list, but be to recognize that certain hazards are inherent in thecause of the low concentration that must be moni widespread production and use of chemicals, many tored, or at least averaged during the lengthy of which are known or at least suspected to be toxic. periods of study required, the sensitivity of detec The acute toxins, whose effects are often spectacu tion and determination must be high. Cost may lar and final, are known even to the general public. pose a limitation. However, many acute toxins such as hydrogen sul The only present type of monitor that meets the fide, sulfur dioxide, and chlorine can be tolerated criteria is some form of passive device. Active for years at sublethal concentrations without any monitors requiring power sources and mechanical apparent harm. For example, most of the profes components such as motors, pumps, and metering sors exposed to high daily concentrations of devices impose too many restrictions for their pro hydrogen sulfide in the qualitative analysis labora jected applications in the long-range personal tories years ago seem to have lived to healthy old monitoring of low concentrations of toxic gases. age. Cumulative and additive toxins, on the other hand, are more insidious in their impact and it ap pears that exposure to even minute amounts of such materials over long periods may have lasting effects on the individual. Metabolic changes occur and car cinogenic manifestations develop. Many exposure hazards from toxins in the work place have been recognized and evaluated by various monitoring methods. In general, the evalua tions have been limited to the sampling and analysis of the general atmosphere in the workplace, al though it is obvious that the appraisal of risk should be based on the content of the air actually breathed by the individuals rather than on the composition of the surrounding ambient air. Because cumulative and additive toxins are long-term hazards, it is the time-weighted-average exposure that should be monitored through exposure studies extending for weeks, months, and even years. Personal monitoring in the community also is needed. Because of the transient nature of many of the exposures encountered in the ambient atmos phere, background information on individual expo sures could be very informative. Away from the place of employment individuals are more mobile, and thus data on the total exposure of persons Active devices The initial approach to personal monitoring has been based on the use of devices consisting of a bat tery-pack to power a motor-driven pump that pulls ambient samples through a metering unit. The sam ple itself is usually collected on a tube of activated charcoal, although in some modifications the sample is absorbed in an appropriate buffered or complexing solution or is simply pumped into a col lection bag. Active sampling monitors have provid ed most of the data for the pioneer studies that have been done thus far. Such monitors have serious limitations, however; they are quite expensive, the pumps have relatively short service periods before repair or replacement is necessary, use is limited to the length of time that a charge can be maintained on the batteries, and the monitors have tended to be a nuisance to the wearer because of their bulk, weight, and the noise generated by the pump. These problems contribute to a lack of cooperation by wearers who resent the device and may in some cases lead to deliberate distortion of the samples and consequent invalidation of the results obtained. living in high-risk or suspect areas would be excep- Dr. H'esl is Boyd Professor of Chemistry, Environmental Sci ences Institute. Chemistry Department, Louisiana Stale Univer sity. Passive devices Personal monitors for determining toxic expo sures in residential areas as well as in the workplace OCC 8231 must be convenient and low in cost. The monitors must provide the necessary sensitivity, accuracy, and reliability for obtaining sufficient usable data. Passive monitors are ideally suited for such applica tions because of their convenience, simplicity, and relatively low cost. Gas permeation through poly mer membranes is an attractive approach for quan tifying the collection of gaseous samples in passive monitors. Monitors using this technique are unique because environmental variations induce little, if any, error. The devices also can be adapted to a variety of analytic systems, including sample ad sorption on solid substrates such as activated char coal or silica gel, and samples can be collected in solutions containing reactive species for the fixation and stabilization of the toxins of interest. Permea tion-type monitors correspond in size, weight, and convenience to the familiar radiation dosimeters. Although this paper will emphasize permeationtype monitors, some discussion of other passive de vices is appropriate. In a sense, effects measure ments, such as those obtained with corrosion cou pons, lead peroxide candles, or sulfation plates, present the simplest approach to passive monitor ing. However, these provide no means for quantify ing the results in terms of concentration and there fore must be considered only as qualitative indica tors of the presence of corrosive agents or sulfur di oxide. Evacuated vessels have been used for the collection of air samples. Although this approach has no power and mechanical requirements, it is limited by the small size of the sample that can be collected. The most widely used approach for pas sive monitoring is based on the collection of sam ples by means of diffusion which can be quantified by application of Fick's Law. Permeation and diffusion are similar in many re spects, yet involve certain important differences, principally in the mode of action. Whereby diffu sion represents an application of Graham's Law in which gas molecules pass through tubes or holes, permeation is essentially a solution process in which gas or liquid molecules come in contact with a solid or liquid barrier, where they dissolve and penetrate and ultimately saturate the barrier. In diffusion, the holes serve to minimize turbu lence as the gas molecules pass through the exposed orifice. Beyond the orifice, mass transfer takes place across a stagnant space to a collecting surface. The quantification of the collection process is pro vided by Fick's Law of diffusion: N = ~DA (dc/dx) where N = rate of diffusive transport (mol/sec), D - diffusivity of the species (cm'/sec), A = area of diffusion path (cm1),* = path length (cm), and c = concentration of species (mol/cm1). Collection of diffused molecules usually is achieved by adsorption on the surface of an activat ed charcoal fabric, as advocated by the 3M Corpo ration as well as by the British Defense Ministry at Porton Down. Palmes1*1 has developed a monitor for nitrogen dioxide that eliminates the dependence on charcoal fabrics, an approach that shows promise for other applications. Commercial diffu sion-type monitors are convenient, require no cali bration, and are quite versatile, although they are generally limited to the monitoring of those organic gases that adsorb strongly on charcoal surfaces. The monitors are discarded after a single use be cause the units can be mass-produced and cost only a few dollars each. Although such costs may be modest they may be a significant factor if longrange studies are contemplated involving a large number of subjects. Monitor evaluations per formed in the United Kingdom1 have indicated that relative air movement and humidity variations each introduced some error. Permeation devices Permeation was introduced by O'Keeffe and Ortman4 as a means of preparing standard gas mix tures. The reverse of this process was introduced by Reiszner and West5 for quantitatively collecting sul fur dioxide from the ambient atmosphere. This application was based on the fact that the rate at which a given gas permeates a given membrane is a fixed value, and that the total mass of the gas that is transported through the membrane becomes a func tion of the concentration of that gas in the ambient atmosphere and the time of exposure. The collect ing mechanism for transported gases can be an ad sorption medium, such as activated charcoal or sili ca gel, or it can be an absorption system involving a sofution that captures and stabilizes the permeated species. In the case of S02 the capture and stabiliza tion was achieved by absorption in a solution of tetrachloromercurate (11) to form the very stable sulfitodichloromercurate (II) complex. The amount of SO2 in the collected sample was measured by the color that developed upon addition of acidbleached pararosaniline and formaldahyde, as used in the original West-Gaeke procedure. Knowing the amount of gas collected and the exposure time per mits the calculation of the time-weighted-average concentration, C; thus C = wk/t OCC 8232 U " KJ (3 4fin / membrane VJL 41 mm- Figure 1 Design of permeation-type personal monitor. "PLATE where w is the weight of collected gas (pg), t is the time of exposure, and k is the permeation constant. The permeation constant, or more properly the cali bration constant, is characteristic of each mem brane and gas and is determined simply by exposing the device or membrane to a standard atmosphere of the gas of interest for an appropriate time. From the weight of gas collected, the constant is calculat ed: k = Ct/w Once calibrated, a permeation device can be used indefinitely without recalibration or servicing other than to remove the collected samples and recharge with the appropriate sorbing material. Permeation-type monitors are durable, versatile, convenient, accurate, and reliable. Nothing wears out or degrades, so long-term service can be expect ed. Its versatility is evident in the wide choice of sorbing systems that can be incorporated--solids such as activated charcoal, silica gel, ion exchange granules, or their mixtures can be used, and also sol vent or solution absorbers. Samples are contacted rather than drawn through the sorbing media, elim inating any breakthrough problems. Sloshing or spilling problems are avoided by close containment of liquids. It is the author's opinion, based on theory and experience, that sample collection of gases by means of permeation is as accurate, or more so, as any sampling technique now in use. Primary gas standards provided in the form of per meation tubes contribute to the accuracy of the method. The reverse process utilizing permeation for gas sampling is also accurate. There are no known interferences with the sam pling process itself due to copollutants. The analytic finish of the collected samples includes any defi ciencies inherent in the particular process used, whether it be gas chromatography, spectrophoto metry, or any other applicable technique. Permea tion-type sampling is essentially free from environ mental stresses. Neither relative air movement nor humidity has an effect and temperature effects can be minimized or eliminated by use of membranes made of silicone polymers. The principal deficiency of personal monitors based on permeation is the need to calibrate each device for the toxin to be sampled. Once calibrated, however, the device can be used for months or even years without recalibration. A second drawback may be cost. A calibrated monitor costs about ten for vinyl chloride. times as much as a diffusion-type unit, but this is quickly offset because it can be repeatedly reused. Thus, even for a two-week study, it has cost advan tages. Charcoal and pump devices may cost ten times as much and have relatively high repair and replacement costs. The first personal monitor using permeation was the vinyl chloride monitor,* which was widely evaluated in field studies in the United States as well as abroad.7 The essential details of construction of a permeation-type personal monitor are shown in Figure 1, and Figure 2 is a photograph of a manu factured monitor (Real Inc., West-Paine Labora tories). To date, monitors fo eight different toxins have been developed. Design and performance details are given in Table 1. Typical results of field tests are listed in Table 2. Studies are being performed on the development of monitors for hydrogen fluoride and for formaldehyde. Potentially, permeation-type monitors should be possible for all gaseous toxins, both organic and inorganic. Highly sensitive and high-capacity long-range units and permeation applications for high concentration alarm devices are foreseeable in the future. References OCC 8233 1. PALMES, E D. and GUNNISON, A.F., J. Am. Ind. Hyg. Assoc. 34. 78-81 (1973). 2. PALMES, E.D., GUNNISON, A.F., D1MATTO, J., and TOMCZYK. C..J. Am. Ind. Hyg. Assoc. 37, 570-7(1976). 3. LAWES, H., personal communication. 4. O'KEEFFE, A.E. and ORTMAN, G.C., Anal. Chem. 30, 760 (1966). 5. RE1SZNER. K.D. and WEST, P.W., Environ. Sci. Technot. 1, 526(1973). 6. NELMS, L.H.. REISZNER, K.D., and WEST, P.W., Anal. Chem. 49, 994-8 (1977). 7. WEST, P.W. and REISZNER, K.D., J. Am. Ind. Hyg. 39, 645 (1978). 8. HARDY. J.K.. DASGUPTA. P.K., REISZNER, K.D., and WEST, P.W., Environ, Sci. Technoi. 13, 1090-92(1979). 9. PITTS. W.D., REISZNER, K.D.. WOLCOTT, J,, DASGUPTA, P.K., and WEST, P.w., Interim progress report on personal monitoring of alkyl lead compounds, unpublished com munication (1978). 10. REISZNER, K.D. and WEST, P.W., unpublished material. 11. FOLKES. L.A., REISZNER, K.D., and WEST, P.W., Environ. Sci. Technoi., in press. 12. HARDY. J.K., SAVAR1AR. C.P., and WEST, P.W., un published material. 13. HARDY, J.K. and WEST, P.W., unpublished material. Table 1 Permeation-type personal monitors (or selected toxins Toxin Chlorine* Membrane Dimethyl silicone (DMS) (single-backed) Sorber Buffered (pH 7) Fluorescein 0.0057(m> NaBr(0.31%) Sulfur DMS Tetrachloro- dioxide* (single-backed) mercurate(ll) Vinyl DMS Act. charcoal chloride* (single-backed) (CSj desorption) Alkyl lead' DMS (unbacked) Silica gel (IC1 desorption) Benzene'* Silicone polycarbonate Ammonia" Vinyl silicone Act. charcoal (CSj desorption) 0.6% Boric acid Hydrogen DMS 0.2N NaOH, sulfide" (single-backed) 0.003M EDTA Hydrogen DMS 0.1N NaOH cyanide" (single-backed) Analytic finish Spectrophotometric (eosin produced) Sensitivity 0.013 ppm (8-hr exposure) Remarks Environ, effects: none On the spot colorimetry inherent West-Gaeke (spectro photometric) Gas chromatograph Spect rophot ometric (dithizone) or AAS Gas chromatograph Spectrophoto metric (Nessler's reagent) Spectrophoto metric (methylene blue method) Spectrophoto metric (pyridinebarbiturate acid reagent) 0.01 ppm (B-hr exposure) 0,02 ppm (linear to 50 ppm +) 0-2 pg 0.02 ppm (8-hr exposure) 0.4 ppm (8-hr exposure) Temp, effect: - 0.05% per *C Other environ, effects: none 1-4 weeks sampling possible Environ, effects: none Thoroughly field tested Temp, effect: - 0.66% *C/ TEL +0.11% per *C/TML Other environ, effects: none Temp, effect: - 1.2% ppm *C Other environ, effects: none Temp, effect: + 0.57%/'C Other environ, effects: none 0.01 ppm Environ, effects: none 0.01 ppm Temp, effects: - 0.2% per *C (8-hr exposure) Other environ, effects: none Table 2 Results of typical field tests Sulfur dioxide (area monitoring), pg/m* Permeation device <5 156 West-Gaeke <2 -- Coulometric <25 144 156 158 132 128 17 386 382 <25 Permeation device 0.47 1.10 0.80 0.90 0.93 Chlorine,-ppm Cb Impinger 0.52 0.67 0.56 1.10 1.20 0.80 0.90 0.90 0.40 0.20 0.30 0.97 1.10 1.10 Permeation device 0.98 0.12 0.11 0.05 0.08 0.92 0.97 Vinyl chloride, ppm Pump -- charcoal tube 0.63 0.07 0.07 0.88 OXY Occidental Ch mical Corporation Environment, Health & Safety z4, 5 & 0 MEMO Tn pr m Subj Ct W. E. Driscoll ^ R. L. Comboy 0^ Date April 15, 1986 Industrial Hygiene Assessment Action Plan Dates - On January 28, 1986 I visited Pottstown to assist G. D. Lloyd in locating sampling points for monitoring the ventilation systems. At that time I reviewed the status of recommendations submitted as a result of our last industrial hygiene assessment which was conducted May 7-9, 1985. At that time I asked G. D. Lloyd to send me new action plan dates as several of the action dates had passed with no progress on the recommendation. Since January 28, I have asked G. D. Lloyd several times by telephone to give me new action dates on the outstanding recommendations. I made a formal request in writing on April 2, 1986. OCC 8235 OXY Oriental Chemical Corporation Environment, Health & Safety To From Subject K. H. Garner/R. M. Zelley R. L. Comboy '&>y Industrial Hygiene Assessmentt //1i99a85 cc: D. L. Lull J. M. Coburn W. E. Driscoll J. W. Swanson G. D. Lloyd tfe . <2.3f. I MEMO Date -May 14, 1985 Attached please find the industrial hygiene assessment which was recently conducted in your facility. The action dates in the recommendation section of the report were agreed upon during the closing conference. If you have any questions, please do not hesitate to contact me. RLC/blp 5842E-28 Attachment OCC 8236 Industrial Hygiene Assessment Pottstown Plant Armand Hammer Boulevard Pottstown, PA 19464 May 7-9, 1985 Conducted by R. L. Comboy - Corporate Industrial Hygiene On the above dates, an industrial hygiene assessment was conducted in the Pottstown facility. The purpose of the assessment was to review the effectiveness of industrial hygiene activities and program elements including management structure, workplace hazard recognition, the monitoring program and the adequacy of control for potential health hazards. This report is based on extensive discussions with Gerry Lloyd, Manager Safety, observation of all plant operations, and review of industrial hygiene sampling records. Recommendations, discussion and the pre-assessment questionnaire will be found on the attached pages. RLC/6291E-1 OCC 8237 Status of Previous Industrial Hygiene Recommendations December 1982 Pottstown Facility 1. All locations in the plant with noise levels in excess of 90 dBA should be posted as hearing protection areas. (Complete) 2. In accordance with OCC Procedure #04:01:02:032, all employees must be notified of their industrial hygiene sample results even though the result is below the allowable exposure limit. (Complete but needs to be reinstituted.) 3. The respirator program should be changed to reflect the following: a. Scott canister seals will not be removed unless the respirator is to be used. (Complete) b. Canisters will be dated as to when they are put into service and will be disgarded 12 months later even though the seal has not been removed. (Complete) 4. The written respirator program for the Calender Plant needs to be formally updated to reflect the current usage of disposable respirators. (Complete) 5. The written respirator programs need to be updated to reflect the currently used fit testing procedures. (Complete) 6. A formal program to document an employee's medical ability to wear a respirator must be instituted. (Incomplete - see current recommendations.) 7. Laboratory hoods in the RAD area should be operated with the sashes lowered as much as possible to maximize the inflow air velocities. Current inflow air velocity are substandard and consideration should be given to upgrading this system, (Incomplete - see current recommendations.) 8. A formal program to periodically evaluate all ventilation systems to determine performance, needs to be instituted. (Incomplete - see current recommendations.) 9. A formal laboratory quality control program with an outside laboratory needs to be implemented. (Complete) RLC/6291E-2 OCC 8238 RECOMMENDATIONS 1. A formal program to document an employee's medical ability to wear a respirator must be instituted. 2. In order to obtain a proper respirator fit, facial hair must not interfere with the respirator seal. A policy must be developed and implemented pro hibiting the growth of facial hair which interferes with the respirator seal for those employees who may have to wear a negative pressure respirator. 3. The welding shop in the Resins Plant must be provided with adequate local exhaust ventilation. 4. A formal program to periodically evaluate the efficiency of ventilation systems must be implemented. Corporate will assist. 5. The industrial hygiene database for VCM monitoring must be brought up-to-date so that the procedure for notifying employees of sample results below 1 ppm can be reinstituted. Corporate will assist. 6. The Job Code Dictionary in the industrial hygiene database must be updated to accurately reflect employee activities during the sampling period. 7. Housekeeping on the blender level in the Calender Plant must be improved. 8. Proper storage must be provided for respirators used by employees on the blender and banbury decks in the Calender Plant. 9. Since inflow air velocities in the R&D laboratories are substandard, a procedure must be Implemented to insure that hood sashes are lowered as far as feasible at all times to minimize potential employee exposures. Agreed Action Date August 1, 1985 (Implemented) January 1, 1986 (Implemented) November 1, 1985 (Completed) October 1, 1985 (Program developed) September 1, 1985 (Completed) June 1, 1985 (Completed) Immediate July 1, 1985 (Completed) July 1, 1985 (Implemented) RLC/6291E-3 OCC 8239 DISCUSSION Medical Ability to Wear a Respirator OCC Safety Procedure #04:01:03:05 and OSHA regulations require that employees be medically evaluated for their ability to wear a respirator. A means of meeting this requirement will be found in Attachment I of this procedure. It was agreed that this procedure would be implemented by August 1, 1985. Facial Hair Policy In order to obtain a proper face to facepiece seal with a negative pressure respirator there must be no facial hair in the area of the seal which would reduce the effectiveness of the respirator. This requirement will be found in OCC Safety Procedure #04:01:03:05 and in the OSHA regulations. Section 1910.134, A policy must be developed by the facility whereby facial hair will not be permitted in the area of the respirator seal for those employees who may have occasion to wear a respirator. It was agreed that such a policy would be developed and implemented by January 1, 1986. Welding Shop At the present time the welding shop in the Resins Plant is located in a small room with four welding stations. General exhaust ventilation is provided at one end of the shop. No local exhaust is provided at the welding stations. It is my understanding that an AFE has been written to relocate this shop to a larger area and provide local exhaust ventilation at the welding stations. The AFE is currently in the approval stage. If for some reason this AFE is not approved, local exhaust ventilation must be provided at the welding stations In the present shop. It was agreed that this project would be completed by November 1, 1985. Ventilation Systems A routine evaluation program is needed for all local ventilation systems. Initial design data and, ideally, initial air flow measurements are needed as baseline performance data. Regular air flow measurements should be performed on all systems to identify changes in system performance. These data can then be used to recommend specific corrective action as needed to maintain acceptable ventilation rates. Scheduled monitoring of ventilation systems is particularly important in the RAD area where good local exhaust ventilation is the primary control to limit employee exposure. RLC/6291E-4 OCC 8240 DISCUSSION (Continued) It was agreed that this monitoring program would be developed by October 1, 1985 and that Corporate would assist. VCM Industrial Hygiene Database For a number of reasons including lack of computer space and personnel changes, the VCM database is not current. Subsequently, the procedure for notifying employees of their sample results when the result is less than 1 ppm has not been utilized. In order to reactivate this procedure this database must be brought up to date. It was agreed that Pottstown would input current data and that Corporate would input the remainder of the data. This project should be completed by September 1, 1985. One element in this database is a job code which reflects the employee activities during the sampling period. This Job Code Dictionary needs to be updated. It was agreed that Pottstown would input these data by June 1, 1985. Housekeeping Housekeeping throughout the facility was generally good except for the blender level in the Calender Plant. It was agreed that this item would receive immediate attention. Respirators Disposable dust respirators are used for comfort in the Calender Plant. When not in use, these respirators must be stored in a contaminant-free environment such as in a plastic bag. At the time of the survey we observed at least 17 improperly stored respirators on the blender and banbury decks. The OCC Respirator Procedure and OSHA regulations require proper storage of respirators when not in use. It was agreed that this item would be completed by July 1, 1985. RAD Laboratories The inflow air velocities for the laboratory hoods in the Research and Development area are substandard when the sashes are raised to the top. For this reason it is imperative that these sashes be lowered as much as possible to maximize the use of the volume of air available. RAD employees should be instructed to lower the hood sashes as much as is practical to minimize the possibility of vapors or fumes from the hoods escaping into the laboratory. It was agreed that this procedure would be implemented by July 1, 1985. RLC/6291E-5 OCC 8241 INDUSTRIAL HYGIENE PROGRAM REVIEW Date 5/9/85 Facllity Pottstown_________________ Respondent G. D. Lloyd Title Manager - Safety Circle appropriate response where indicated. 1. Is there a written policy for industrial hygiene? (a) Yes 6. No. c. No, but one is being prepared d. Part of the Safety Policy 2. The Individual in charge of the industrial hygiene section reports directly to (Check each applicable term or statement) (a) Plant Manager b. Director of Occupational Health Program c. The Personnel Manager d. The Safety Manager e. The Plant Engineer f. Other - Specify 3. Who is responsible for industrial hygiene sampling? a. Equipment calibration G. D. Lloyd and J, Sprat b. Sample collection G. D. Lloyd and J. Sprat c. Employee observation during sampling G. t>. Lloyd and it. $prat d. Recording production and exposure information G, D. Lloyd/J. Sprat 4. How frequently are airflow calibrations of air samplers made? (Check each applicable term or statement) a. Annually () Other periodic frequency (specify) Before and after each sample Fixed monitors - daily 5. Where are air samples analyzed? (Check each applicable term or statement) (a) Plant laboratory d. Comnercial laboratory (names) NATLSCO 6. Is there an active laboratory quality control program associated with industrial hygiene analyses? Please describe on a separate sheet of paper or attach protocol. Yes 7. Who is responsible for the review and maintenance of industrial hygiene sampling documentation? G. D. Lloyd and J. Sprat Attach a copy of the sample documentation form currently in use. RLC/6291E-6 OCC 8242 2- - 8. How frequently are all noise survey equipment calibrated? Specify Before and after each use 9, How are employees specifically informed about the industrial hygiene hazards of their jobs? Safety meetings 10. Is there a health and safety committee in this facility? Yes b. No 11. How often does this committee meet? Monthly 12. List job titles of current members. Safety Manager____________ 3 - Union Reps,___________ 2 - Company Reps._________ ________________ ________________ ________________ 13. Have all processes been reviewed for all potential health hazards? c. Don't know 14. Are regular walk-through surveys performed to note the presence of potential health hazards? Yes b. No How frequently? (e.g., annually, etc.) At least bi-weekly By whom? Safety Manager, Plant Manager 15. How often is worker noise exposure monitored? Specify Every 2 years RLC/6291E-7 OCC 8243 -3- 16. What do you consider to be your problem materials and/or physical hazards? List in order of decreasing importance and indicate estimated number of people at risk to each material or hazard. Material or Hazard Number of People at Risk VCM 300 17. To whom are reports of worker exposure determinations routinely sent? (Check each applicable term or statement) @ Worker's department roj Medical department on need to know basis g Plant engineering (dp Establishment superintendent rap Labor - Management Health & Safety Committee (Fp Corporate medical or industrial hygiene office g. Other 18. Are local exhaust ventilation hoods and area ventilation inspected periodically for integrity and/or need for maintenance? a. Yes (5) No, but will develop action plan c. There are no local exhaust hoods If yes, how often and by whom? 19. Is there a written respirator program? (a) Yes - attach copy D. No .20 Are earmuffs and/or plugs provided when noise exposures are above 90 dBA? () Yes b. No c. Other actions taken RLC/6291E-8 occ 8244 -4- 21. Are work practices observed periodically to assure that proper methods are being used? (0 Yes (Give approximate interval) b. No c. Not applicable 22. Are records of significant worker exposure to toxic materials kept so that each worker's exposure can be estimated? Yes b. No 23. Is there a written Industrial Hygiene Sampling Program for this facility? a) Yes No RLC/6291E-9 OCC 8245 OXY Fr m SAFETY DEPARTMENT - PVC RESINS DIVISION Subject INDUSTRIAL HYGIENE AUDIT - POTTS TOWN - 12/83 We are in the process of completing the items listed in your audit report for Pottstown. We have had a number of discussions on how to handle your item #8 - periodic evaluation of ventilation systems. Our review indicates that this job will be a very costly and time consuming project. What we need at this point is a clarification from you on what exactly you want done and how you feel the checks should be made. As you know, we have a great number of ventilation systems and wall fans and we need your input on how exactly to check their performance. Would you please drop me a line listing some specifics on how you think we should check ducted air systems, wall fans, etc., and with what so that the cost and time consumption would not he prohibitive. Thanks for your help. G. D. Lloyi GDLrmas cc: Mr. K. H. Garner Mr. R. H. Zelley Mr. T. E. Ptoses RECEIVED n.nil 1983 ENVIRONMENT, health & safety; /fju/'. OCC 8246 oxr OV ccidental Ch mical Corporation Environimnt. Health 4 Safety ______Jerry Milkenfeld Fr m Mitchell Zavon 1/5 Subiect Pottstown Industrial/tiy^iene Assesstgfent Your Memo May 3, 1983 / </Q 6- mem<3 Date way / You asked about two points. I have discussed both points with Bob Comboy who in turn has discussed this with Gerry Lloyd, the Safety and Health Director for the Pottstown plant. The OSHA vinyl chloride regulation states that a sampling program will be conducted "without regard to the use of respirators". Many jobs in this facility require the use of respirators. For example, a respirator is needed on reactor entry. If an employee is wearing a monitor the day he does a job requiring use of a respirator, the monitor will record a VCM exposure but the employee is protected by a respirator, usually an air line respirator. We are complying with the OSHA dicta but it would not be practical to put someone on the job of monitoring the individuals in order to record that at a certain time they were wearing a respirator when the monitor recorded excessive exposure. During the seventies, 8 to 10MM was spent on engineering controls to reduce the VCM exposure in this plant. At the present time controls appear to be reasonably adequate. You also asked about the noise exposure and the hearing conservation program. There is only one area in the calender department where an employee's noise exposure may exceed 85 dBA on a time weighted basis. Other areas of the plant that are above 90 dBA are not normal work areas. Since these areas are entered infrequently, hearing protective devices will suffice. Now that we have had a year or more of more intensive assessment, perhaps the first real assessments in industrial hygiene that have been done in this company, we will be taking a second and still more intensive look at specific plants and specific processes within the plant. This will not indicate that the situation has deteriorated but rather that we are trying, by careful evaluation and targeting our analyses, to upgrade the standard of health protection throughout the operations. 3126E-1 OCC 8247 e-f 10889 WILSHIRE BOULEVARD SUITE 1500 LOS ANGELES, CALIFORNIA 90024 MEMO OCCIDENTAL PETROLEUM CORPORATION y01 & PHONE: 879-1700 208-8800 To Mitch Zavon From Jerry Wilkenfeld Subject: Pottstown Industrial Hygiene Assessment December 14-/5, 1982 Date May 3, 1983 cc: J. Tinkler F, Friedman D. Giannotti In reviewing the above named assessment and the facility response to the recommendations two items are noted which need further elaboration. These are in the discussion section on page 3. 1. Under Employee Notification it is stated that "A review of the VCM data for 1982 indicates that more than half of the samples taken currently require employee notification." Since employees are only notified when measurements exceed the personal exposure limit, I would appreciate receiving further information on the plant's program aimed at reducing this rate. 2. Under Hearing Conservation Program it is noted that some of the areas of the plant exceed 90 dBA and are posted as hearing protection areas. Please advise if these areas have been reviewed to determine whether utilization of hearing protection is adequate or if engineering controls should be considered. JW/ym Attachment w 1 o 1983 Environment health A "AFETY OCC 8248 'a Occid ntal Chemical Corporation Envir nment. Health & Safety K. Garner T ____ E. Lapreziosa From _ M. R. Zavon, M.D. Subj ct Industrial Hygiene Assessment - cc: F. F. Hoy J. T. Wolfsperger R. J. Schuttler G. D. Lloyd - w/o Appendices H. F. Dubec - w/o Appendices MEMO Date March 3, 1983 i The attached assessment has been discussed in detail with Gerry Lloyd but an action program in response to the recommendations needs to be furnished. Would you please have the written program to me within 60 days. 2689E-1 Attachment OCC 8249 - Industrial Hygiene Assessment Pottstown Plant Armand Hammer Boulevard Pottstown, PA 19464 December 14-15, 1982 Conducted by R. L. Comboy - Corporate Industrial Hygiene On the above dates, an industrial hygiene assessment was conducted in the Pottstown facility. The purpose of the assessment was to review the effectiveness of industrial hygiene activities and program elements including management structure, workplace hazard recognition, the monitoring program and the adequacy of control for potential health hazards. This report is based on extensive discussions with Gerry Lloyd, Manager Safety-PVC Resins Division, observation of all plant operations, and review of industrial hygiene sampling records. At the time of the assessment the plant employed 432 in the Resins Department, 230 in the Fabricated Products Department and 75 were employed in Finance, Administration and Employee Relations. Recommendations and discussion will be found on the attached pages. The pre-assessment questionnaire, organization chart, process description, plant layout and ventilation testing program will be found in the Appendices. 2427E-1 OCC 8250 RECOMMENDATIONS 1. All locations in the plant with noise levels in excess of 90 dBA should be posted as hearing protection areas. 2. In accordance with OCC Procedure #04:01:02:032, all employees must be notified of their industrial hygiene sample results even though the result is below the allowable exposure limit. 3. The respirator program should be changed to reflect the following: a. Scott canister seals will not be removed unless the respirator is to be used. b. Canisters will be dated as to when they are put into service and will be disgarded 12 months later even though the seal has not been removed. 4. The written respirator program for the Calender Plant needs to be formally updated to reflect the current usage of disposable respirators. 5. The written respirator programs need to be updated to reflect the currently used fit testing procedures. 6. A formal program to document an employees medical ability to wear a respirator must be instituted. 7. Laboratory hoods in the R&D area should be operated with the sashes lowered as much as possible to maximize the inflow air velocities. Current inflow air velocity are substandard and consideration should be given to upgrading this system. 8. A formal program to periodically evaluate all ventilation systems to determine performance, needs to be instituted. 9. A formal laboratory quality control program with an outside laboratory needs to be implemented. 2427E-2 OCC 8251 DISCUSSION Hearing Conservation Program The plant has been surveyed for noise and where it was suspected that employee exDosure may exceed the eight hour time weighted average of 85 dBA, noise dosimetry has been conducted. Regular audiometric examinations have been offered for some time. Though the areas where employee time weighted average exposure exceeds 85 dBA have generally been posted; areas above 90 dBA which are not routine employee work areas have not been posted. Data from the plant noise survey should be reviewed to identify those areas which exceed 90 dBA. These areas should then be posted as hearing protection areas. The employees need to be trained and the warning signs worded so that everyone knows that hearing protection is required while working in exposures of greater than 90 dBA regardless of the time SDent in these areas. Employee Notification The plant routinely monitors for vinyl chloride monomer (VCM) in accordance with Federal regulation 1910.1017. The custom at this facility has been to formally notify the employee in writing only if the sample result exceeded the permissible exposure limit. The employees are, however, aware that they can have access to their sample results at any time. A review of the VCM data for 1982 indicates that more than half of the samples taken currently require employee notification. To insure that all employees are aware of their VCM exposure and to comply with the OCC Employee Notification Procedure #04:01:02:032 all employees should be notified of their sample results. The facility may want to consider posting these results (those below 1 ppm) as opposed to individually notifying employees in writing. Respirator Program Dust Respirators The Pottstown facility has a detailed written respirator program for both the Resins Plant and the Fabricated Products Plant. Since this program was written, there has been a change in the type of dust respirator used in the Fabricated Products Plant. The written program should be updated to reflect this change in respirator usage. Medical Ability to Wear a Respirator In accordance with OCC Procedure #04:01:03:05, Respiratory Protection, and OSHA 1910.134, a program to medically evaluate an employee's ability to wear a respirator must be instituted. The OCC procedure describes how this is to be done. 2427E-3 Scott VCM Respirator At the present time the Resins Plant is using a Scott canister for VCM protection. This canister is Catalog #08H-VC-L with NIOSH approval #TC-14G-85. The limitations on this canister imposed by the NIOSH certification are: 1. May not be used in VCM concentrations exceeding 25 ppm. 2. Must be discarded at the end of the shift during which it is used regardless of actual usage if seal has been broken. Currently some employees remove the seal at the beginning of a shift and discard the canister 8 hours later or after 4 hours of use. The canisters cost $14.50 each. Considerable money can be saved if the seals are not removed unless the respirators were actually going to be used. Employees are instructed to Idave the area when the alarm sounds unless they must be there and then only with an airline respirator. It is therefore recommended that the respirator program be changed to reflect the following: 1. Scott canister seals will not be removed unless the respirator is to be used. 2. Canisters will be dated as to when they are put into service and will be discarded 12 months later even though the seal has not been removed. R&D Laboratories The inflow air velocities for the laboratory hoods in the Research and Development area are substandard when the sashes are raised to the top. For this reason it is imperative that these sashes be lowered as much as possible to maximize the use of the volume of air available. R&D employees should be instructed to lower the hood sashes as much as is practical to minimize the possibility of vapors or fumes from the hoods escaping into the laboratory. Routine ventilation testing is discussed in the next section and applies to the R&D facility. 2427E-4 Ventilation Systems A routine ventilation evaluation program is needed for all local ventilation systems and building or general ventilation. Initial design data and, ideally, initial air flow measurements are needed as baseline performance data. Regular air flow measurements should be performed on all systems to identify, changes in system performance. These data can then be used to recommend specific s. corrective action as needed to maintain acceptable ventilation rates. Scheduled monitoring of ventilation systems is particularly important in the R&D area where good local exhaust ventilation is one of our primary controls to limit employee exposure. Appendix II presents a proposed ventilation testing program extracted from the OCC Industrial Hygiene Field Manual. Laboratory Quality Control To assure ourselves that we are obtaining good data, a laboratory quality assurance program is essential. In the past the laboratory has exchanged samples with other OCC laboratories. While this practice is commendable, it does not provide an independent third party check on the data. One or two samples for each type of analysis we perform in-house should be sent to an accredited industrial hygiene laboratory at least on an annual basis for verification of results. An accredited laboratory must be used because it will already be in a national laboratory quality control program where their proficiency is already demonstrated and documented. 2427E-5 OCC 8254 APPENDIX I INDUSTRIAL HYGIENE PROGRAM REVIEW Date 13/2/82 Facility Occidental Chemical Corp. Respondent G. D. Lloyd Location Pottstown___________________ Circle appropriate response where indicated. Title Manager - Safety PVC Resins Division 1. Is there a written policy for industrial hygiene? a. Yes b. No. (c) No, but one is being orepared d. Part of the Safety Policy (Copy of White Springs Policy sent to G. D. Lloyd) 2. Is there a procedure for review and response to industrial hygiene recommendations by the affected operating group? CD Formal b. Informal c. No 3. The individual responsible for industrial hygiene is: (Check each applicable term or statement) a. An experienced industrial hygienist. Primarily responsible for other functions. (Safety, Medical Training) 4. The individual in charge of industrial hygiene has had this responsibility for: (Check applicable term or statement) a. Less than one year b. One to five years ^ More than five years (18 years) 5. The individual in charge of the industrial hygiene section reports directly to (Check each applicable term or statement) a. Plant Manager b. Director of Occupational Health Program c. The Personnel Manager d. The Safety Manager 1 & The Plant Engineer Other - Specify Director of Manufacturing 6. The industrial hygiene staff consists of: (Check each applicable term or statement and give number in each category) Full time industrial hygienist(s) Industrial hygienist(s) or other professional who spends a portion of his time on industrial hygiene problems c. Full time technician(s) d. Part time technician(s) OCC 8255 7. Consultative services are obtained from the following source or sources and with the following frequency: (Check each applicable term or statement and list consultants used) As Problems Arise Other Specify a. Insurance companies b. Independent Consultants None utilized to date 8. Arrangements have been made for the industrial hygiene section to obtain service from other staff or assistance in the following areas: (Check each applicable term or statement and state source of service) a. Noise b. Ventilation Engineering " c. Ionizing radiation " d. Air analysis R&D and Analytical Lab e. Engineering control Engineering f. Other (describe) 9. If Industrial Hygiene Sampling is performed in-house, is the following available: (Check each applicable term or statement) () An office area for industrial hygiene staff A storage area for equipment (c) A laboratory area for equipment, calibration and sample analysis 10. Who is responsible for industrial hygiene sampling? a. Equipment calibration G. D. Lloyd b. Sample collection G. D. Lloyd__________ ___________ c. Employee observation during sampling G. D. Lloyd d. Recording production and exposure information 6. D. Lloyd 11. How frequently are airflow calibrations of air samplers made? (Check each applicable term or statement) * a. Annually b. Other periodic frequency (specify) Before and after each use -2- OCC 8256 12. Where are air samples analyzed? (Check each applicable term or statement) Q Plant laboratory b. Commercial laboratory (names) To select one 13. Is there an active laboratory quality control program associated with industrial hygiene analyses? If yes, please describe on a separate sheet of paper or attach protocol. 14. Who is responsible for the review and maintenance of industrial hygiene sampling documentation? _______ G. D, Lloyd____________ ________ Attach a copy of the sample documentation form currently in use. 15. Please indicate the air sampling instruments available to take samples for subsequent laboratory analyses on a separate sheet of paper. See Page 11 16. Please list the portable direct reading instruments for air analysis which are available for use by the industrial hygiene section, and give number of units as appropriate on a separate sheet of paper. See Page 11 17. On a separate sheet of paper please list the noise and heat stress measuring instruments available for use by the industrial hygiene section. See Page 11 18. How are calibrations of direct reading instruments for airborne contaminants maintained? (Check each applicable term or statement) a. Use manufacturer's calibrations fED Use only NIOSH certified indicating tubes (c) Calibrate periodically in known concentrations of gas or vapor 19. How frequently are all noise survey equipment calibrated? Specify Before and after each use 20. How are employees specifically informed about the industrial hygiene hazards of their jobs? Through supervision Through training programs % 21. Are employees oriented to potential health hazards and preventive measures: (Check each applicable term or statement) By supervisors? By orientation sessions? By printed material (give example) d. No orientation of employees VCM standard. Appendix to lead standard -3- OCC 8257 22. Are supervisors informed of potential health hazards, necessary monitoring, and proper operation and maintenance of control devices? a. Routinely b. Occasionally c. Seldom d. Never () As the need arises 23. Is this information given in (Check each applicable term or statement) /a) Formal training sessions? (jy Written instructions and memoranda? c. No formal procedure 24. Is there a health and safety committee in this facility? (aj> Yes b. No 25. How often does this committee meet? Monthly_____________ 26. List job titles of current members. Manager, Safety - Chairman Manager of Maintenance (Resins) Plant Engineer (Fab Prod) Safety Supervisor (Resins) Two clock card______ representatives for location 27. Does the industrial hygiene section maintain a current file on materials in the facility which may pose a health hazard potential? (a} Yes b. No c. Not as such \ 28. Have all processes been reviewed for all potential health hazards? (a^ Yes b. No c. Don't know -4- OCC 8258 29. Are all new chemicals or processes cleared for potential health hazard introduction? Always b. Usually c. Seldom d. Never 30. Do purchase specifications for equipment routinely include limits on noise production? (a) Yes b. No State Criteria Not to exceed 85 dBA 31. Are special handling procedures required for specific toxic materials? (For example, carbon tetrachloride, carbon disulfide, toluene diisocyanate, beryllium, tetrachloroethane, etc) c. If yes, attach procedure. Used only in lab area (R&D or Analytical) & kept under lock and key. Quarterly reminder. 32. Are regular walk-through surveys performed to note the presence of potential health hazards? Q. Yes b. No How frequently? (e.g., annually, etc.) Monthly By whom? Safety Committee and G. D. Lloyd 33. How are walk-through survey results transmitted to production management? Verbally unless a condition warrants a written report - then verbally with follow-up report 34. How frequently are all SOP's revised for health hazard control? Annually or as needed By whom? 6. D. Lloyd and/or Production 35. Attach summaries of air contaminant studies conducted in the last two years including: a. Substances sample b. Types of samples c. Number of samples and range of results -5- OCC 8259 36. At what concentration is a regular monitoring program for air contaminants set up? State criteria. When initial determination indicates the need 37. Average exposures of workers to air contaminants are determined by: (Check each applicable term or statement) /a) Personal sampling of all affected workers (D Personal sampling of representative affected workers c. Area sampling d. Average exposures are not determined 38. How is area monitoring data used to evaluate occupational exposures? It is not used to evaluate exposure dose. It is used only as an alarm system. The production areas do average out reading on occasions, however, they useless for determining exposure unless backed by ,iob-time-motion studies 39. What is the procedure for responding to employee health hazard complaints? What guidelines are established for the timeliness of this response? Employee reports to supervisor. If not resolved it goes to Safety Committee member and Plant Production Manager or Plant Manager. At this point it becomes a committee item. Potentially serious problems are reported directly and correction dates established. 40. How often is worker noise exposure monitored? Specify Annually, or as needed or requested 41. What do you consider to be your problem materials and/or physical hazards? List in order of decreasing importance and indicate estimated number of people at risk to each material or hazard. Material or Hazard Number of People at Risk Vinyl Chloride _________250 -6- OCC 8260 42. What is the procedure for review arid establishment of CEL's for materials without AEL's? Literature Review MSDS Corporate industrial Hygiene and Medical Procedure 43. To whom are reports of worker exposure determinations routinely sent? (Check each applicable term or statement) a. Worker's department b. Medical department Plant engineering Establishment superintendent fei Labor - Management Health & Safety Committee (f) Corporate medical or industrial hygiene office g. Other EASE 44. Are lunch rooms or areas provided for all personnel? (j) Yes b. No 45. Is there a system for transmitting industrial hygiene recommendations on new or revised processes to the engineering designers? (a) Yes, please specify. d. No Fund 46. Do you use your industrial hygiene data to recommend specific control measures? @ Always b. Usually c. Occasionally d. Never 47. Are new and/or modified processes inspected after design and after evaluation by industrial hygiene to assure that work conditions are healthful and meet all applicable standards? Q Always b. Usually c. Special situations only d. Seldom or never Specify -7- OCC 8261 48. Are noise control devices inspected periodically for integrity and effectiveness? Yes b. No c. There are no noise control enclosures If yes, how frequently and by whom? (specify) Annually or sooner if needed 49. Are local exhaust (1) ventilation hoods and (2) area ventilation inspected periodically for integrity and/or need for maintenance? Yes b. No c. There are no local exhaust hoods If yes, ,how. often and by whom? (1) Occasionally (2) Seldom Done 80. Are maintenance employee environmental exposures being routinely evaluated? Yes b. No Specify Part of VCM Monitoring Program 51. Is there a written respirator program? a^ Yes - attach copy No 52. Are respirators checked for suitability and approved for intended use? Yes By whom Safety Dept, and Production b. No 53. Are users instructed and trained? G} Yes By whom G. D. Lloyd and Production b. No OCC 8262 -8- 54. What action is taken to insure that respirators are worn? Specify Monthly checks, job observations, monthly inspections, disciplinary action program 55. Are earmuffs and/or plugs provided when noise exposures are above OSHA requirements? c. Other actions taken Employees with hearing loss are medically restricted to wearing protection 56. Is the wearing of hearing protection enforced? Q Yes By whom Supervision b. No 57. Are face shields or goggles provided where necessary? Yes b. No c. There are no areas where their use would be necessary 58. Is protective clothing provided? (a) Yes, where necessary 6. No c. There are no areas where it would be desirable 59. Are processes where chemicals have been substituted checked periodically to assure that lower hazard materials are still being used? Yes By whom? G. D. Lloyd b. No 60. Are work practices observed periodically to assure that proper methods are being used? Yes (Give approximate interval) Monthly Job Observation Program b. No c. Not applicable ' 61. Are records of significant worker exposure to toxic materials kept so that each worker's exposure can be estimated? -9- OCC 8263 62. Are records of air contamination kept by area so that changes can be readily identified? 9 Yes . No 63. Are records of inspection of control devices, e.g., ventilation systems kept? Yes b. No 64. Are records of ventilation quantities for each exhaust hood kept and associated with static suction or other simple inspection measure? Yes b. No 65. Does the industrial hygiene section participate in employee orientation for potential emergency and safety hazards in the facility? Yes b. No RLC:2430E 1/24/83 OCC 8264 -10 15. Air Sampling Equipment 1. SIPIN SP-1 (3) 2. Bendix Super Sampler (3) 16. Direct Reading Air Sampling 1. Bendix Gastec, 100 ML (1) 2. Century - Several 3. HNU - Several 17. Noise 1. Gen Rad, 1954 Indicator (2) 2. Gen Rad, 1982 Sound Level Meter (1) 3. Gen Rad, 1954-9710 Exposure Monitor (3) Heat Stress 1. Wet Bulb, Black Globe, Dry Bulb Arrangement. Full location summer and winter profiles completed. % -11- OCC 8265 APPENDIX II 1. Testing of Ventilation Systems Air flow measurements and test data are often needed in connection with the proper functioning and design of industrial exhaust systems. The importance and value of obtaining test data can be noted in the following applications. a. To determine whether a new exhaust system is functioning in accordance with design data. b. To obtain air flow data necessary for proper setting of blast gates on systems designed for blast-gate balancing. c. To determine, by periodic checks, if further maintenance or repairs of a system are necessary to assure efficient operation. d. To obtain measurements necessary to determine whether the system has sufficient capacity for additional hoods or future exhaust equipment. e. To obtain design data from existing satisfactorily controlled operations for future installations of similar character. f. To obtain air flow data necessary to determine the degree of compliance with state codes, regulations or trade association standards. 2427E-6 OCC 8266 Z. Ventilation System Surveys A. System Start-up vs Design Basis Any ventilation system, be it local exhaust for contaminant control or general for comfort, is designed in terms of removing or distributing a specified quantity of air at a specified velocity at a total system pressure which is the sum of the parts. An initial survey of the system is the only time a valid comparison can be made between the design basis and optimum system performance. B. Survey Procedures 1. Sketch of the system. A sketch, not necessarily to scale but representative of dimensions, should be drawn noting such items as hoods, elbows, branchings, air cleaner, fan and stack. Supply ducts, plenums, and diffusers should be shown for general systems. The sketch should be considered as part of the permanent record on which future changes in the systems may be recorded. 2. Specific air flow measurements. Measurements in terms of air flow, velocity, and static pressure must be made to determine that the system is adequately balanced and performing according to the design basis. These measurements include: a. Statis pressure measurements at: o hoods o up and downstream of the air cleaner o up and downstream of the fan b. Air flow in cfm at: o hoods (throat suction method) o branches and mains (Pitot tube) ( o up and downstreams of fan JPitot tube) c. Supply, capture, and conveying velocities at: o diffuser outlets (supply velocity) o face or opening of hood (capture velocity) o branches and mains (conveying velocity) 2427E-7 OCC 8267 d. Fan performance o fan speed in rpm o horsepower (BHP) calculated using cfm (Q), total pressure (TP), and mechanical efficiency (ME) of fan. BHP = (Q) (TP) 6356 x ME The locations of the measurements must be identified on the sketch and a record kept for future comparisons. The measurements obtained should agree within 10% of the design basis. If not, system modification should be made until such agreement is obtained. 3.. Other checks. Local exhaust systems are installed for the singular purpose of removing some contaminant from the work environment. Visualization techniques using smoke tubes or candles can be most helpful in verifying that the system exerts a sphere of control over a sufficient area to prevent excessive exposures to operating personnel. Air evaluation, for specific contaminants, is also recommended to verify the system will control contaminants to levels known to be safe. Air samples taken in the breathing zone of operating personnel will be most helpful in assessing the adequacy of contaminant control. C. System Operating vs System Start-up Once systems are started up and determined to perform satisfactorily, the degree of evaluation can be reduced as long as good records of start-up or initial conditions have been made. Experience with air flow systems clearly indicates periodic surveys are required to assure system performance is adequate. Operating personnel cannot be relied upon as an "indicator" of system performance. Also, ventilation systems are rarely an integral part of the operation in terms of quality and production and all too often receive inadequate maintenance. 1. For most systems simple velocity measurements at exhaust hoods and supply ducts will provide a * crude indication of system performance when compared with start-up evaluations. For local exhaust systems, the throat suction method applied to exhaust hoods and static pressure differentials for air cleaners and fans will suffice in confirming the system is performing satisfactorily. The throat suction method will provide valid information unless: o The hood entry has been modified/damaged; 2427E-8 OCC 8268 FIGURE 5.1 Information Needed for a Detailed Ventilation Summary Point Measurement Location of measurement Measurement use A Hood static pressure Distance from hood-- 3 pipe diameters-flanged or plain hood 1 pipe diameter-tapered hood 1. estimate flow: 0 = 4005 CeA SPh 2. check point for hood and system performance. B Velocity and static Branch and mains-preferably 7.S 1. transport velocity pressure diameters straight run downstream from 2. exhaust volume: Q = VA nearest air disturbance (el, entry, etc.) 3. SP as system check point C Centerline VP Small ducts location as above. Round duct only. Use on smalt ducts Centerline velocity reading only. where traverse impractical or where approximate volume wanted. 0 Static, velocity and Inlet and outlet of fan-any two of total pressures three readings at each location 1. Fan static and total pressures FSP = SPo + SPi - VPi TP = SPo + SPi + VPo - VPi 2.Motor size or CFM estimate ____ CFM x TP " 6356 X ME of fan 3.SP as system check point E Static pressure Inlet and outlet of collector Differential pressure F Face velocity Hood face-measure at center of hood face cross-sectional areas 1 .Compare pressure drop with normal operating range 2.Checkpoints for maintenance. Readings above or below normal indicate plugging, wear or damage to collector elements, need of cleaning 1.Estimate capture velocity Average face velocity measurements 2.Determine hood performance.* I Adapted from Industrial Ventilation, 16th ed, ACGIH. 1960. 'Observation ol ait Hows surrounding exhaust openings may be visually augmented by use of smoke generators, trails and streamers. 7-8 o There are obstructions ahead of the point of measurement; or o The system has been modified. However, a reduction in throat suction can provide valuable information, such as an indication that there has been: o Accumulations of materials in an elbow, branch, or main, thus clogging or restricting air flow. Accumulation in the elbows result from impaction, while build-ups in straight runs result from insufficient conveying velocity or overloading the system. o A change in blast gate setting if the system is balanced using blast gates. o Additional branches and hoods added to the system. "Adding on" to a system is a real temptation. It is not sound economics when it renders the entire system deficient. o Excessive build-up on the filter. It is best to monitor filter build-up by attaching a static pressure measuring device across the filter (manometer). o Reduced fan output resulting from belt slippage, damaged or worn rotor, or build-up on the fan blades. 2. Smoke tubes are also helpful in identifying uneven air flow patterns near hood entry areas and the effect of room air currents on the performance of hoods. D. Data Handling and Recording The sketch of the system made at start-up or for the initial air evaluation survey and the results of the ensuing air flow survey must be recorded and filed in such a manner that future air flow surveys can be conducted in a similar manner. The frequency of air flow surveys can only be determined by such conditions as: o Nature of the materials being controlled. The more hazardous the materials, the more frequently ^he system should be checked. o Nature of the system. Blast gate systems and laboratory hoods will require more frequent checks than other systems. o The degree of maintenance. Air flow surveys can be used to indicate the need for more frequent and improved maintenance. 2427E-9 OCC 8270 APPENDIX III Organization Chart R. F. Gervais S. P. Dominick, Jr, Vice President & General Manager Resins F. F. Hoy Director-Manufacturing G. D. Lloyd Manager-Safety (Hygiene) Open Vice President & General Manager Fabricated Products J. T. Wolfsperger Director-Manufacturing H. F. Dubec Manager-Safety & Environment (Hygiene) 2427E-10 OCC 8271 ( Calender Plant The Film and Sheeting Division takes the above resin(s) and compounds them with other ingredients such as plasticizers, stabilizers, lubricants, fillers, and colorants. The blended material is then Banburyed, milled and calendered into film along four calendering lines. The film is shipped in roll form either to the Salisbury printing plant or to trade customers for further processing. 2427E-11 OCC 8272 / I } i ! ! OCC 8273 PL^ST/ SOL r i^y. S' COPOLYMER* SUSPENSION RESIN MANUFACTURE FLOYP DkAORAM co eov/mR / i ftlfa fri^ OCC 8274 ) J. T. Wolfsperger R. J. Schuttler G. D. Lloyd H. F. Dubec / Attached please find the correct Page 4 and 11 for this assessment. Please remove any Page 4's and 11's in the original copy sent to you and replace it with the attached. My apoligies for any inconvenience. 2709E-1 Attachment OCC 8275 - Occidental Chemical Corporation Environment, Health & Safety T From Subject 0. Wilkenfeld M. R. Zavon / _________ Pottstown Indu___________________ sessment cc: S. P. Dominick R. L. Comboy e-r MEMO Enclosed is a copy of the Pottstown Industrial Hygiene Assessment. The facility response to the recommendations will be found following our recommendations. If you have any questions regarding this report, please call me. 2990E-1 Enclosure OCC 8276