Document ex6xBvXY9bxvzmQe2L3xdRd9

ANZ 0004209 ASARCO, Incorporated Department of Environmental Sciences Salt Lake City, Utah Plant: CORPUS CHRISTI Survey Date: June 23-July 3, 1975 Field Work by: John B. Richardson Report Date: August 29, 1975 ENVIRONMENTAL SURVEY 1. OPERATING CONDITIONS At 5:50 a.m. on 6/23/75 calcine build up on the walls of the Lurgi Roaster sloughed off, forcing the roaster down for the duration of the survey. The acid plant immediately ceased operating at this time. As a result of roaster shut-down both oxide and sulfide cell houses went on 48-hour stripping cycles. During normal operation the aluminum cathodes are usually stripped every 24 hours. On 6/24/75 Raymond L. Skinner and Karl G. Ammersbach from the Occupational Safety and Health Administration (OSHA) arrived unannounced in response to a five-page union grievance alleging unsafe health and safety conditions throughout the plant. From 6/24-7/2/75 OSHA and ASARCO collected concurrent air samples and noise measurements. Construction of the new Dross Mill precluded operation of the existing Dross Mill on day shift. Number 1 Zinc Dust unit in Sulfide Casting was down during the survey. The Sulfide Leach Department was not casting cadmium sticks the week of 6/30/75. Otherwise, operations were normal. II. SAMPLING A. A.I.S.I. tape samplers were used to collect one-hour sequential samples of airborne dust, fume and/or acid mist at the following locations: ANZ 0004210 Department Sulfide Cell House Oxide Cell House Sulfide Zinc Casting Oxide Crushing Oxide Electric Furnace Sulfide Leach Cadmium Casting Sulfide Reverb Furnace 2 Date 6/23/75 6/23/75 6/25/75 6/25/75 6/26/75 6/27/75 7/1/75 Location East side of cells (upwind) West side of cells (downwind) 5' south of casting area 5' west of automatic feed manganese hopper, at charge end of crushing cycle Charge deck, north of charging port 5' northwest of melting pot 5' north of charge port The above samples were analyzed for lead, zinc, manganese and cadmium by atomic absorption. The titrametric method outlined in the NIOSH Criteria Document for acid mist was utilized for cell house samples. B. M.S.A. personal monitors equipped with closed-face Millipore filters were used to collect individual dust, fume and/or acid mist samples. One personal monitor equipped with a closed-face preweighed Millipore filter was used as a fixed location sampler inside the Lurgi Roaster during clean out. These samples were analyzed for lead, cadmium, zinc and manganese by atomic absorption spectrophotometry. Arsenic analyses were performed using an arsine generation, color imetric method. Acid mist samples were titrated according to the NIOSH method cited above. In some instances pre weighed Millipore filters were used to collect total dust samples. C. Ventilation was measured in the laboratory using an Alnor Type 8500 thermo-anemometer. D. Noise measurements were taken in the Sulfide Zinc Dust Manufacturing area with a General Radio Type 1558-A octave band analyzer. Internal calibration preceded each set of measurements. A B&K Calibrator Type 4230 was used to calibrate the analyzer (94 dB-1000 Hertz) after the survey in Salt Lake. ANZ 0004-21 1 3 E. Individual noise exposure data were collected using DuPont audio dosimeters, Models D-100 (measures exposure in terms of the present 90 dBA OSHA standard) and D-285 (records noise exposures according to the 85 dBA limit proposed by EPA, et al).* A DuPont readout unit was used to decode each dosimeter memory cell and produce a reading as a percentage of either the 90 dBA or the 85 dBA standard. III. SAMPLING RESULTS A. A.I.S.I Tape Samplers: Department Location Ele ment Concentration (mg/m3) Mean Max. Min. Percent No. of Exceeding Hourly OSHA Graph Samples Limit No. Sulfide Cell East side of cells House (upwind) HpS04 Mist <.09 <09 <09 45 0 _ __ Oxide Cell House West wall (downwind) h?so4 Mist <35 1.83 4". 07 42 5i Sulfide Zinc Casting area Casting Pb <01 .01 <.01 29 Zn .08 .19 .05 -- 0-- 0-- Oxide Crush- Charge end ing Pb .07 .41 <.01 27 72 Zn 1.96 8.96 .11 -- 0-- Mn <-07 .54 <.01 -- 0-- Oxide Electrie Furnace Charge deck Pb ZnO Fume <01 1.20 .01 6.77 <.01 .03 25 -- 0-- 83 Sulfide Near melting pot Leach Cadmium Cast- ing Cd <01 .02 <-01 7 0-- Sulfide Reverb Charge deck Pb ZnO Fume <01 1.40 .01 5.90 <01 .33 23 -- 0-- 4-- * In Noise Standard hearings in Washington, D.C., both the Environmental Protection Agency (EPA) and labor unions support an 85 dBA standard. The Occupational Safety and Health Administration (OSHA) has recommended that the present 90 dBA standard remain unchanged. ANZ 0004212 4 OSHA LIMITS: Pb Zn ZnO Fume Mn Cd Fume H2S04 Mist 0.2 mg/m-* No standard 5.0 mg/m-* 5.0 mg/m-* 0.1 mg/m-* 1.0 mg/m^ B. Personal Monitors: Department Oxide-Cell House Job or Employee and Number Operation Jesus Salazar #322 (no respirator) Stripper J. Sauceda #338 (no respirator) Stripper R. Villarreal #340 (no respirator) Stripper S.M. Garcia #1578 (no respirator) 5 P. Bosquez # 1565 (no respirator) J. Lascano #344^ (no respirator) 5 A. Yanez #156 (no respirator) 5 R. Flores #498 (no respirator) 5 A. Ramirez #414 (no respirator) A. Flores #175^ (no respirator) 5 E. Cano #704 (no respirator) Stripper Stripper Stripper Stripper Stripper Stripper Stripper Stripper Sampling 1975 Time Date (Min.) 6/24 85 Ele ment h2so4 Mist Cone'n. (mg/m^ .46 6/24 82 h_so4 Mist <.19 6/24 79 h2so4 Mist .67 6/24 74 h2so4 Mist .43 6/26 325 6/26 309 6/26 351 6/26 251 6/26 331 h2S04 Mist H S04 Mist h2so4 Mist h2so4 Mist Mil?4 .31 .41 .20 < .06 .04 6/26 256 6/26 364 MlSt4 h2so4 Mist .11 .63 ANZ 0004213 5 Department Sulfide Cell House OxideLead Pot Job or Employee and Number Operation Sampling 1975 Time Date (Min.) Ele ment M. Martinez #550 (no respirator) 5 R. Ramirez #414 (no respirator) Cell Inspector 6/23 104 Stripper 7/1 310 MHf,iSs0t 4. h,so4 Mist F. Roldan #382 (no respirator) S. Garcia #1578^ (no respirator) Cell Inspector 6/23 102 Stripper 7/1 387 H2S4 Mist H S04 Mist R. Ovalle # 1665 (no respirator) D. Deleon #372^ (no respirator) Stripper Stripper 6/25 250 7/1 354 H2S04 Mist h2so4 Mist G. Rodriquez #520 (no respirator) R. Ovalle #16655 (no respirator) Stripper Stripper 6/25 249 7/1 360 h,so4 Mist h2so4 Mist' C. Garcia #557 (no respirator) Stripper 6/25 245 h2so4 Mist J. Lascano #344 (no respirator) Stripper 6/25 244 h2so4 Mist 5 Martinez #1541 (no respirator) J. Alaniz #1533^ (no respirator) J. Silva #5995 (no respirator) Laborer Laborer Laborer 6/24 413 Pb 6/24 416 Pb 6/24 336 Pb Cone'n. (mg/m3) .68 1.381 .35 .75 .57 .53 .66 .21 .19 .16 .05 .04 .03 ANZ 0004214 Personal Monitors continued 6 Department SulfideZinc Dust Job or Employee and Number Operation Sampling 1975 Time Date (Min) A. Villearreal #5015 No.2 Zinc Dust 6/30 (no respirator) Unit Operator 217 T. Morales #860 (no respirator) No.2 Zinc Dust Operator 6/27 393 R. Quintero #794^ No.2 Zinc Dust 6/30 Unit Helper 220 A. Villearreal #501^ No.2 Zinc Dust 7/1 (no respirator) Unit Operator 327 R. Quintero #794^ (no respirator) No.2 Zinc Dust 7/1 Unit Helper 316 Sulfide Leach Cadmium Casting J. Ramirez #423 (no respirator) J. Casas #361 (no respirator) P. C. Perez #1529 (no respirator) J. Ramirez #423 (no respirator) Oxide- D. Aleman #267 Purification (no respirator) Casting Operator Cuts, weighs Cd sticks Leadman Helper Operator 6/23 6/27 6/27 6/27 6/27 384 309 344 309 357 Element Total Part. Zn Total Part. Zn Total Part. Zn Total Part. Zn Total Part. Zn. Cd Cd Cd Cd As OxideLeach SulfideZinc Cast- ing C. Valdez #357 (no respirator) G. Martinez #1148 (no respirator) Relief Leadman Operator 6/27 342 As 6/25 258 Zn Cone'n. (mg/m3) 2.91 .81 11.39 8.98 6.47 3.65 4.24 1.87 4.78 2.08 .01 .03 .01 .02 2 .011 2 .078 6.35 OxideCrushing C. Benavidez #437 (no respirator) Loader Oper. 6/27 362 Zn Mn 5.84 .08 ANZ 0004215 Personal Monitors continued 7 Department SulfideReverb OxideElectric Furnace Maintenance Job or Employee and Number Operation G. Morin #515 (no respirator) Chargeman M. Resio #113 (no respirator) Chargeman 0. Garcia #823 (no respirator) Lead Burner Sampling 1975 Time Date (Min) 7/2 400 7/2 385 7/2 104 Element Zn Total Part. Zn Total Part. Pb B. Personal Monitor -- Stationary; Department Location Sampling 1975 Time Date (Min) Lurgi Roaster Sampler attached to pole and placed inside roaster through northwest overhead port during clean out. Breathing zone level. 6/28 498 Element Pb Zn Cd As Cone'n. (mg/m3) ,253 6.25 .05 2 .009 Total 4 Particulate 16.74 Cone'n. (mg/m3) .74 3.65 .05 2.63 .13 Exceeds OSHA 8-hour, time weighted average (TWA) sulfuric acid mist (H2SO4) 2 Exceeds proposed OSHA 8-hour, TWA for inorganic arsenic. 3 Exceeds OSHA 8-hour, TWA for lead. 4 Exceeds OSHA 8-hour, TWA for nuisance dust (total particulate) 5 Concurrent sample (OSHA AND ASARCO) ANZ 0004216 8 OSHA Limits: Pb -------- = 0.2 mg/m^ Cd Fume- ----- = 0.1 mg/m^ Cd Dust- ----- = 0.2 mg/m3 Zn --------- = No standard ZnO Fume ----- = 5.0 mg/m^ Total Particulate- = 15.0 mg/m^ H2S04 Mist - - - - = 1.0 mg/m^ Mn------- - = 5.0 mg/m^ As 0.5 mg/m^ (present) As 0.004 mg/m^ (proposed) C. Ventilation Measurements: Department ________ Location___________ Laboratory Hoods-northeast corner Operating Conditions Normal Average Face Velocity (FPM) 50 Hoods-southeast corner H2S04 fuming hood (west side) Muffle furnace hood (east side) Hoods-northwest corner Hot plate hood (east side) Perchloric hood (Recommended average face velocity for lab oratory hoods: 100 fpm; 100-150 fpm for perchloric hoods) Atomic Absorption Hood Normal Normal Normal Normal 70 80 55 80 Flame on; air con ditioner off Flame off; air conditioner off 75 95 ANZ 0004217 9 D. Octave Band Sound Level Measurements: Depart ment Frequency Range (Hertz) SulfideZinc Dust 18.75-37.5 37.5-75 75-150 150-300 300-600 600-1200 1200-2400 2400-4800 4800-9600 9600-19200 Inside Booth 1,4 Outside Booth 2,4 84 dBA 81 dB 71 dB 70 dB 69 dB 68 dB 64 dB 60 dB 61 dB 64 dB 57 dB 93 dBA 77 dB 80 dB 80 dB 84 dB 82 dB 83 dB 82 dB 82 dB 87 dB 8 3 dB Outside Booth 3 93 dBA 76 dB 77 dB 78 dB 84 dB 83 dB 86 dB 85 dB 82 dB 87 dB 82 dB Near Instru ment Panel 2 97 dBA 84 dB 86 dB 85 dB 86 dB 84 dB 85 dB 86 dB 87 dB 89 dB 82 dB 1 No. 2 Zinc Dust Unit operating; air conditioner in booth on. 2 No. 2 Zinc Dust Unit operating; measurements taken between zinc slabs falling from moulds. 3 No. 2 Zinc Dust Unit down; no zinc slabs falling. ^ Graph number 4 compares inside vs. outside measurements. ANZ 0004218 E. DuPont Audio Dosimeters: Depart ment Employee and No. Dosimeter No. ^ Job or Operation Sampling 1975 Time Date (Min.) Percent Readout Based on Sampling Time(Min) Percent Readout Adjusted to 8 hrs. >115 dBA?3 SulfideZinc Dust T. Morales #860 8 D A. Villarreal 8 #501 6 R. Quintero 2 #794 6 A. Villarreal 8 #501 6 R. Quintero #794 ,, 2 7 A. Villarreal 7 #501 7 R. Quintero #794 6 7,8 A. Gomez #753 6 7,8 H. Williams 7 #366 Operator Operator Helper Operator Helper Operator Helper Helper Operator 6/25 363 6/30 213 6/30 22 0 7/1 317 7/1 316 7/22 349 7/22 349 7/29 346 7/29 344 145 41 31 77 55 80 85 75 63 2 192 Yes 92 68 2 117 84 no2 1172 2 104 88 No No No No No Yes No Yes OxideUnload ing N. Nunez #159 (Muffs worn) A H. Delgado #919 B Car Shaker Helper 6/25 367 6/25 365 81 63 9 106 Yes 83 No Sulfide- J. Garcia C Stripper Cell #1544 House P. Bosquez 2 Stripper #1565 6/25 345 6/25 342 67 53 93 No 74 No ANZ 0004219 11 DuPont Audio Dosimeters continued Depart ment Employee and Number Dosi meter Job or No.1 Operation Sampling 1975 Time Date (Min) Percent Readout Based on Sampling Time(Min) Percent Readout Adjusted to 8 hrs. 3 >115 dBA? Paint Shop B. Orrick #260 B. Orrick #260 1 Sandblaster 6/25 349 l4 Sandblaster 6/27 289 5 8 6/27 289 No Reading No Reading 33 No Read- Yes ing No Reading 55 -- Yes 1 Numbered dosimeters record noise in terms of the present 90 dBA OSHA standard. Lettered dosimeters integrate noise according to an 85 dBA, 8-hour limit. 2 Exposures exceeding 100% may violate the OSHA 90 dBA standard, assuming the adjusted percent readout correctly reflects sound levels that would be received in an 8-hour period. OSHA usually does not cite unless the exposure exceeds 120%. 3 The dosimeter records any level over 115 dBA during the sampling period. Under OSHA exposure to steady state noise in excess of 115 dBA for any length of time is not allowed. 4 Dosimeter located outside sandblaster's hood. 5 Dosimeter located inside sandblaster's hood. Concurrent sample (OSHA and ASARCO) 7 Samples collected by plant personnel. 8 Both zinc dust units operating. 9 Exposure exceeds the 85 dBA standard proposed by EPA. ANZ 0004220 12 IV. COMMENTS A. Sulfide Department: Tape and personal monitoring results for airborne cadmium in Cadmium Casting were acceptably low. No respiratory protection was worn and the results indicate none was necessary. Tape and personal monitor sampling showed low airborne lead and zinc levels in the Reverb and slab casting areas. With the exception of the R. Ramirez sample on 7/1/75, all Cell House tape and personal monitor results were below the OSHA 8-hour time-weighted average (TWA) for sulfuric acid mist. Many of these samples were taken concurrently with OSHA, as noted. Noise dosimeter readings were below the OSHA 8-hour TWA of 90 dBA. The Zinc Dust Unit personal monitor showed acceptable levels of airborne zinc dust and total particulate. The Zinc Dust area was the subject of extensive concurrent (OSHA and ASARCO) and independent (both ASARCO D.O.E.S. and Corpus Christi plant personnel) sampling with noise dosimeters between June 25 and July 29, 1975. Several conclusions may be tentatively drawn. First, results indicate that the 115 dBA level is periodically exceeded. Under OSHA no excursion above the 115 dBA limit for steady state noise is allowed at any time during an 8-hour shift. Second, results suggest that the newlyconstructed sound booth, built as an engineering control to reduce individual noise exposures, is not being suff iciently used. Third, dosimeter data show that with only one dust unit operating, operator and/or helper tend to receive noise exposures which exceed the 90 dBA limit as an 8-hour TWA. Fourth, operation of a zinc dust unit with operator only allows this worker minimal relief from areal noise. Relief would be afforded by his frequenting the sound booth or by leaving the premises temporarily (see T. Morales' result). An operator without helper must constantly tend the operation. From the standpoint of efficiency, Universal Scheduling has recommended zinc dust manufacturing as a one-man operation per each dust unit. Individual noise data render this assessment untenable from the standpoint of good industrial hygiene practice. A possibly workable compromise proposed by plant safety personnel is employee rotation, a valid administrative control under OSHA. One employee would work four hours in the zinc dust area then ANZ 0004221 13 move to a low noise area for the remainder of the shift. However, the single result for Morales indicates that with just one. dust unit operating, one worker could receive essentially all noise exposure allowable for 8 hours in about four hours. For the remainder of the shift the worker would have to be assured of noise exposure below the 90 dBA level. With two dust units operating, individual noise exposure could be greater than that indicated for Morales. The question of whether employee rotation will keep exposure within allowable limits should be resolved by sampling with noise dosimeters. One operator had earplugs in his pocket. Hearing pro tection was not observed to be worn at any time during several hours of observation of operator and helper. Respirators were worn during baghouse cleanout only. Octave band analysis of noise in the zinc dust area shows the highest sound level at the 4800-9600 Hertz (cycles per second) range. The range where damage to hearing in the speech frequencies can occur is generally regarded as 2000-4000 Hertz. Decibel levels at these frequencies are higher on the zinc pot platform than near the door of the sound booth. An operator with no helper spends most of the time between platform and air jet. Damage to hearing can be averted by relieving the operator and allowing him either time in the sound booth or time away from noise. Until administrative or engineering controls can be' affected, ear muffs or plugs should be mandatory whenever the dust units are operating. Graph 4 shows sound attenuation characteristics of the sound booth. Attenuation at selected frequencies ranges from 9 to 26 decibels (dB). Overall, the booth decreases sound levels from 93 down to 84 dBA. Presently plant personnel are designing a sound absorbing panel with built-in observation port to place over the openings to the high pressure air nozzles on the Zinc Dust Units. Since the air jets are the primary sources of areal noise, the panels should measurably decrease sound levels. Upon completion of the project an ex haustive noise survey should be undertaken to determine compliance. B. Oxide Department: Two hourly tape samples exceeded the 8-hour TWA for acid mist in the cell house. 8-hour averages of tape ANZ 0004222 14 sample results, however, show minimal acid mist levels. All personal monitor samples for acid mist were accep tably low. Of the tape samples taken on the Electric F.urnace charge deck, 8% exceeded the OSHA limit for zinc oxide fume, assuming all zinc is present as fume. 8-hour averages are comfortably below the OSHA standard. All lead results for tapes and personal monitors were minimal, as would be expected in an operation where elctrolytically refined zinc is melted and cast. Zinc and total particulate values for personal monitors were below permissible limits. The Lead Pot area was sampled concurrently (OSHA and ASARCO) with personal monitoring devices. ASARCO data show minimal airborne lead levels. Respirators were not worn. Three fans were positioned such that they were bucking prevailing wind and thereby interfering with natural ventilation. The fans could be positioned to better advantage. Both personal samples collected in Leach and Purifi cation were below the present OSHA 8-hour TWA for arsenic. However, both values exceed the proposed OSHA standard. Oxide Crushing tape sampler values showed excursions above the OSHA limit for lead 7% of the time. All 8hour averages for lead are acceptably low. Tape and personal results for zinc and manganese indicate mini mal airborne levels of these elements throughout the sampling periods. Of the two 85 dBA noise dosimeters placed in Oxide Unloading, one (N. Nunez, #159, car shaker) showed that the permissible 8-hour exposure was exceeded by 6%. Under the present 90 dBA OSHA standard the Nunez sample would be within acceptable limits. The Nunez dosimeter registered exposure to noise above 115 dBA, a level which should be exceeded at no time during the shift. Nunez wore ear muffs during car shaking. C. Lurgi Roaster; During cleanout a stationary personal sampling device was positioned inside the roaster at breathing zone level. Airborne levels of lead and total particulate exceeded their respective OSHA standards. Values for zinc, cadmium and arsenic were within acceptable limits. Respirator use is mandatory inside the roaster and is considered optional outside the roaster. The stationary ANZ 0004223 * 15 sample result indicates that respirators should be worn inside the roaster during maintenance operations at all times, i.e. a continuation of current practice. D. Maintenance - Paint Shop: The Obidio Garcia personal monitor sample was below the OSHA limit for lead. Garcia's lead burning project (repairing fitting on electrolyte recirculation pump) was short duration. No fans were used and no respirator was worn. The dosimeter measurement for B. Orrick, #260 (Sand blaster) , taken inside the hood shows low actual timeweighted exposure. However, both dosimeters (inside and outside hood) recorded noise peaks above 115 dBA. For OSHA compliance this level should be exceeded at no time during the work shift. To combat heat stress a vortex tube has been placed in the sandblaster's air line. The tube cools the compressed air that would otherwise enter the hood at ambient (usually warm) temperature. Sandblaster Orrick enthusiastically endorsed use of the vortex tube, which was being used on a trial basis. At one time transite was extensively used at the plant. As one example of former use, carpenters cut sheets into skimming paddles. All work involving transite and asbestos products has now been contracted out. Asbestos cloth is still occassionally used to line launders. No other inventories of asbestos products were noted. E. Ventilation: For the atomic absorption (AA) hood manufacturers recommend a ventilation rate of 400 cfm. The AA hood face is 0.5 ft^ (1' x 0.5'). With flame on the volume is 38 cfm (0.5 x 75). 48 cfm (0.5 x 95). is sub-standard. With flame off the volume becomes The ventilation rate in both instances All hoods have inadequate draft and should be upgraded. Lowering the sash to provide greater face velocity should serve only as an interim step in improving overall labor atory ventilation. With such low face velocities it is doubtful whether even extensive lowering of the sash would bring air velocities up to an acceptable level. Low sashes may also impede work in the hood areas. ANZ 0004224 i 16 Radial and rip saws in the Wood Shop need to be ventil ated even though transite is no longer cut. Total particulate (wood dust) concentrations appearing in the 1974 survey report demonstrate that local exhaust ventilation is indicated. The system should conform to A.N.S.I. Standard 29.2-1971, Fundamentals Governing the Design and Operation of Local Exhaust Systems. F. Respiratory Protection; Air sampling through the years has shown that most pro duction workers do not need the protection offered by a respirator. Specialty workers, such as welders, acid plant personnel, lead workers, sand blasters and roaster personnel usually wear respiratory protection. Types are noted, as follows: 1. Welders - Welsh Back Pack Dual cartridge respirator with dust pre-filter and Protex 7500-43 cartridges (remove dust, mists, fumes, organic vapors and acid gases). 2. Acid Plant - MSA Comfo II respirator equipped with GMB cartridges (protection against acid gases up to 50 ppm). 3. Lead Workers - MSA Comfo II respirator equipped with Type "S" filters (remove dust, fumes, mists and radon daughters - no gas or vapor protection). 4. Sand Blasters - Del-Monox Purifier filter cartridge (in line filter). Abrasive blasting hoods were recently purchased from MSA. 5. Lurgi Roaster - For cleanout either MSA Dustfoe or AO R-2000 respirators used. In the Lead Shop Mr. Skinner (OSHA) found a case of improper respirator use. An AO R-33 cartridge (removes organic vapors and acid gases only) was being used on an AO R-2033 respirator. An MSA Comfo II respirator equipped with Type "S" filter, or equivalent competitor brand unit, should be worn by lead workers. Care should be taken that specialty workers use respiratory protection geared to their exposure. Proponents of the bandana-type respirator referred to in the 1974 report are still to be found (Oxide Unloading, yard sweeper operator, Lurgi Roaster cleanout, outside roaster). Those indicating need of respiratory protection by wearing bandanas should be encouraged to wear an approved respirator. ANZ 0004225 17 G. Hearing Conservation: Priority employees for annual audiograms are those whose time-weighted average exposure to noise is 85 dBA or greater. Based on audio dosimeter results sandblasters. Oxide Unloading workers and Sine Dust personnel should be sampled without fail on an annual basis, before shift. It was generally observed that workers in high noise areas failed to wear hearing protection, with the exception of Mr. Nunez in Oxide Unloading. H. Biological Monitoring; A review of the biological monitoring records shows that between October 16, 1974 and August 20, 1975 there has been one repeat urine sample requested and no repeats for blood lead. There were no confirmed blood or urinary leads during this period. As of July, 1975, urine samples are no longer collected routinely as part of the Lead Hygiene Program. However, urine samples will still be collected on a regular basis from cadmium workers. IV RECOMMENDATIONS A. The concept of employee rotation in Sulfide Zinc.Dust Manufacturing should be applied. Participating employees should be monitored with audio dosimeters to determine compliance with the OSHA noise standard. In the meantime engineering work should continue on sound absorbent panels to be placed over the air nozzle openings. When the panels are installed the Zinc Dust area should receive a comprehensive noise survey using noise dosimeters, sound level meter, and possibly an octave band analyzer to deter mine the success of engineering controls. The sound booth should continue to be used as frequently as possible by Zinc Dust personnel to lessen their noise exposure. B. Specialty workers cited in the Comments section should wear NIOSH-approved respirators best suited to their exposures. Zinc Dust personnel, furnace chargemen and Wood Shop workers should be encouraged to wear NIOSH-approved respirators in visible dust and/or fume. Bandanas should be phased out and replaced where necessary with respirators. Roaster cleanout crew members may wish to use a barrier cream if skin irritation develops. The use of facelets ("socks") on respirators should be discouraged. NIOSH approval of a respirator is invalidated when equipped with a facelet. ANZ 0004226 * 4 -- 18 -- C. Annual audiograms should be administered without fail to sandblasters, Zinc Dust personnel and the car shaker operator in Oxide Unloading. Hearing protection should be mandatory for Zinc Dust workers. Ear plugs should be worn by sand blasters to attenuate noise above 115 dBA. D. Although all work with transite and asbestos is farmed out, any remaining applications of asbestos (such as lining launders with asbestos cloth) should be discontinued or a substitute material sought. Being free of the rigors of compliance with the OSHA asbestos standard should provide sufficient incentive to clear the plant of the last vestige of asbestos, where possible. Any future purchase of asbestos materials should be done only after all other possibilities for alternative products' use are exhausted. D.O.E.S. would appreciate receiving notification of any asbestos product still in stock or on order, now and at any time in the future. E. All laboratory hoods should be upgraded. Present blowers and ducts should be inspected and cleaned of accretions if necessary. Special precautions should be taken when cleaning surfaces exposed to perchloric acid fumes because explosion hazard may exist. Corroded blowers may need replacing. Fan speed and/or blower size may need to be increased to provide adequate draft at the hood face. Vertical ducts off the hoods offer less friction loss (resistance) to-flowing air than the current duct arrange ment. Since vertical ducts off the hoods are infeasible in the present building (office above), a new laboratory site, such as the old power plant, should be considered. F. The afore-mentioned saws in the Wood Shop should be ventil ated. G. The new Dross Mill (completion date is September 30, 1975), the Sulfide Lead Pot (runs quarterly), and the lead burners working in lead-lined tanks should be sampled using personal monitors to determine compliance with the OSHA lead standard H. The plant should purchase vortex tubes for use by the sandblasters. ANZ 0004-227 * JBR/ms Enclosures cc: CBWhite KDLoughridge KWNelson HLMontague DHSoutar AJGillespie/JPStetson Dr. CHHine EHHaug RCBeckstead MOVarner John B. Richardson Environmental Specialist ANZ 0004228