Document 3N9dKqMJnnkO97QBzxwjdq8YO

r PB * 2 2 9 113 HEALTH HAZARD EVALUATION/TOXICITY determination, western electric COMPANY, INCORPORATED, DUBLIN, CA LIFORN IA Melvin T. Okawa, et al National Institute for Occupational Safety and Health Cincinnati, Ohio June 1973 V DISTRIBUTED BY: National Technical Information Service wIt. we. unrunsnDiiTimMurunT nvci runvmuumruatUnLr 5285 Port Royal Road, Springfield Va. 22151 J Si. 03^1^1 PISLIOG.VAPhIC DATA 5`1EET *. i: j i 5u\`.: It- 1. Kcpu.-t1. NTOSH-TR-CSl-Vh Health Hazard Ev.iluati on/Toxie ity Determination Western Electric Company, Inc., Dublin, Califcrr.i PB 229 113 CO!' 72-7`-51 Kcpo;t Date June 1973 7* \w*l.o:.`iO Melvin T. Okava, and Arnold Bodmer 'r- Oijniranon Nj,tc nnj Address National Institute For Occupational Safety and Health Parklawn Building 5o30 Fishers Lane Rockville, Maryland__________ 2065?____________________________ 12. Sponsoring Organization Name and Address National Institute For Occupational Safety and Health Parkla-:; Building 5o03 Fishers Lane Rockville, Maryland__________20352____________________________ IS. Supplementary Notes $ Oc^nuutio Tlr;* . *v- HKD 72-74-51 10, Proj?c 1/i ask/-oA Unit No. H. Cor.craci/Grant No. 13. T>p? of Rcpan A Period Covered .Final.Sent.1972-Feb.19 14 16* Abstracts In response to a request received from a representative of e_ployees per the authoritj of Section 20(a)(6) of the Occupational Safety and Health Act of 1970, the National Institute for Occupational Safety and Health (lilOSH) conducted a health hazard survey to determine exposure to solvent vapors in the printed viring board processing area of western Electric Company, Dublin, California. Based upon the results of environmental and medical data, it has been determined that trichloroethylene is toxic to workers at the concentrations and conditions used or found at the time of ..this evaluation. It is also Judged that n-propyl acetate and toluene are not potentially toxic at the concen trations used or found. Recommendations have been suggested to management to obviate observed hazards to twenty five affected employees. 17- Key *ords a.ad Docuzienc Analysis. 17c- Descriptors --- Hazardous materials. Toxicity, Toxicology, .riteria. Inspection, Standards, Recommend, tions. Industrial hygiene. Solvents, Toluene 17s. Uc.":tfL:i/Opfn-FndtJ Teims Health hazard evaluation, Toxicity determination. Occupational Safety and Health Act of 1973 , It-propyl acetate Trichloroethylene, Vapors C.O-Vil 1 i/O-o 0o/20 Avjiiii'.blc Lo the tubXic. Rf* hv >Ns,ArrT,IrO*N A*, L7' TEC^Kr^N\i/CrArt'' . A ^ lf.. , ,,* r- . ~,nrr<\ fV'nji ` 't V .. i "j I 7- a'R y C 1 > ( I i'ii F.t p,,.-;) 2J> Ll .`5 (! 1.1* V'v.2-* ';'\n i^''rn 21. \ rf 25 22. P.'i.t 14 i' SL 034152 . . ?v-ISAM HEALTH HAZARD EVALUATION REPORT 72-74-^7 . HAZARD EVALUATION SERVICES BRANCH DIVISION OF TECHNICAL SERVICES Establishment Western Electric Company, Inc. Dublin, California Report Prepared By : Melvin T. Okawa, Industrial Hygienist Arnold Bodner, M.D., Medical Officer Field Evaluation : Melvin T. Okawa, Industrial Hygienist Arnold Bodner, M.D., Medical Officer Carl Ellison, M.D., Medical Officer James Jones, Industrial Hygienist Lucia Eckroth, Research Assistant Phillip Polakoff, M.D, Medical Officer Laboratory Analyses: Russell H. Hendricks, Ph.D. DLCD, Salt Lake City, Utah Larry K. Lowry, Ph.D., Research Chemist DLCD, Cincinnati, Ohio Originating Office ; Jerome P. Flesch, Chief Hazard Evaluation Services Branch June 1973 U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH CINCINNATI, OHIO 45202 . I, 034153 Si* U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH CINCINNATI, OHIO 45202 HEALTH HAZARD EVALUATION REPORT 72-74 WESTERN ELECTRIC COMPANY DUBLIN, CALIFORNIA JUNE 1973 I. SUMMARY DETERMINATION A. Introduction Section 20(a)(6) of the Occupational Safety and Health Act of 1970, 29 U.S.C. 669(a)(6), authorizes the Secretary of Health, Education, and Welfare, following a written request by any employer or authorized representative of employees to determine whether any substance normally found in the place of employment has potentially toxic effects in such concentrations as used or found. The National Institute for Occupational Safety and Health (NIOSH) received sucn a request from an authorized representative of employees regarding exposure to solvent vapors in the printed wiring board processing area of the Western Electric Company plant, Dublin, California. B. Federal Standards -- Three potentially toxic substances were found in the place of_ employment, the printed wiring board processing area of the plant. All three agents have established Federal standards which are promul gated by the U.S. Department of Labor (Federal Register, Part II, Vol. 37, No. 202, 1910.93, Table G-l and G-2). _________ Substance Federal Standard Trichloroethylene.................................................... 100 ppm* N-Propyl Acetate........................................................ 200 ppm Toluene......................................................................... 200 ppm *ppm - parts of vapor per million parts of contaminated air by volume at 25'C and 760 mm of Hg pressure. The standard is based on a time-weighted average for an eight hour day (40 hour per week) exposure. SL 034154 Paae 2 - Health Hazard Evaluation Report 72-74 C. Environmental Evaluation Results Environmental investigations were conducted ty NI3SII on September 13, 1972; December 7, 1972 and February 16, 1973. Nine (9) personal breathing zone samples were collected on employees sprevinc board units with a lacquer containing n-propyl acetate and toluene. The n-propyl acetate (NPA)- concentrations ranged from nor.detectable (0) to 32 parts per million (ppm) with an average concentrations for NPA and (TOL) respectively wore 15.2 and 6.0 ppm. Toluene (TOL) levels were between 0 and 1'' non with an average of 6.0 ppm. Trichlo oethylene (TCE) levels ranged from 13-40 ppn with an average 25.3 ppm. ^ " Twelve personal breathing zone samples were collected on employees washing board units with TCE. The NPA and TOl levels ranged fron 0-6 and 0-2 ppm respectively. The TCE concentrations ranged from 6-82 ppm (average 39.0 ppm). ,_ A Twelve breathing zone samples were collected on workers in the testing area. The NPA and TOL levels ranged from 0-21 and 0-6 ppm respectively. TCE levels ranged from 8-44 ppm (average 24,4 ppm ). ^ Six samples were collected on mass solder machine operators. Only a trace of NPA was found and TOL was not detected-TM" any of the samples. TCE concentrations.ranged from 23-87 ppm with an average of 44.0 ppm. Four samples were taken while mass solder operators cleaned their machines with TCE. TCE levels ranged from 30-106 ppm (average 70.5 ppm). Only one"sample out of 43 showed a level of TCE which represented an excursion above the 100 ppm Federal standard which is based on an eight-hour time-weighted avrage exposure. This level (105 ppm) occurred when NIOSH investigators were_monitorinq a short-term cleaning operation at the mass solder machine. D. Medical Evaluation Results Twenty-four persons were interviewed by NICS11 physicians on December 7, 1972. All but three people had some symptoms which they attributed to their exposures to solvents. The most comoon symptoms of the 24 workers were: (1) nausea (70.84), (2) headache (54.24), (3) dizziness (33.3"'), and (4) mucous membrane irritation (25.04). All the workers felt that their symptoms were relieved completely when they had left the work environment for several hours. SL 034155 Page 3 - Health Hazard Evaluation Report 72-74 Symptoms have occurred on a fairly regular basis, and were reported frequently at the times of our visits. Twenty exposed workers and nine control subjects submitted eight-hour urine samples on February 16, 1973 which were analyzed for TCE metabolite (trichloroacetic acid and trichloroethanol) levels. The trichloroacetic acid (TCA) and trichloroethanol (TC-OH) levels are expressed in milligrams per liter (mg/1) or milligrams per gram of creatinine (ng/g). The control samples showed a TCA range of 0-29 mq/1 or 24 mg/g and a TC-OH range of 0-27 mg/1 or 0-18 mg/g. These levels are slightly higher than those found in control subjects from a previous NIOSH investigation indicating that these people v/ere getting exposure to TCE at the plant. The exposed persons samoles showed a TCA range of 17-196 mg/1 or 11145 ng/g and a TC-OH range of 38-121 mg/1 or 22-111 mg/g. These levels were preshift values. Post work TCA levels did not vary much, but the TC-OH levels were elevated to a range of 82 267 mg/1 or 52 -179 mg/g which indicated that these individuals were exposed to TCE during the day. The TC-OH levels in urine correlate well with the amount of TCE in the atmosphere. The urine TC-OH levels indicated that these workers were being exposed to TCE levels in the atmosphere ranging below 50 ppm on a time-weighted average exposure. No safe urine TCE metabolite levels have been developed for an occupationally exposed group of people at this time. E. Toxicity Determination Based upon the results of the investigation reported above, it is our determination that the substance trichloroethylene is toxic to workers in the printed wiring board unit operations at the con centrations and conditions used, and found at the time of this evaluation. ~ Trichloroethylene is the only agent present is significant amounts throughout the-work area and is thought to be the Cause of the toxic manifestations of symptomatology occurring frequently -- in workers during periods of heavy usage, although environmental levels delected v/ere below the current Federal standard. The reported condition represents a hazard to the health of workers, although not considered serious since no permanent physical changes occur, and may also present the potential for a safety hazard due to the general reduction in motor function, ability to concentrate and increased likelihood of accidents on such occasions. 03A156 Page 4 - Health Hazard Evaluation Report 72-74 It is also judged that the substances, N-orppyl acetate and Toluene, are not potentially toxic at the concentration used or- found. "" " " F. Distribution Copies of the Summary Determination of the evaluation are available upon request from the Hazard Evaluation Services Branch, NIOSH, U.S. Post Office Building, Room 508, 5th and Walnut Streets, Cincinnati, Ohio 45202. Copies have been sent to: a) Western Electric Company, Dublin, California b) Authorized Representative of Employees _c) U.S. Department of Labor - Region IX For purposes of informing the approximately twenty-five (25) "affected employees," the employer will promptly "post" the Summary Determination in a prominent place(s) near where affected employees work for a period of 30 calendar days. .SI 03A157 SL Page 5 - Health Hazard Evaluation Report 72-74 II. INTRODUCTION Section 20(e)(6) of the Occupational Safety and Health Act of 1970, 29 U.S.C. CS9(c)(C), authorizes the Secretary of Health, Education, and Welfare, folic,-ire a written request by any employer or authorized re presentative cf employees, to determine whether any substance normally found in the place of eir.ployr.ent has potentially toxic effects in such concentrations as used or found. The National Institute for Occupational Safety and Health (HIOSH) received such a request from an authorized representative of employees regarding exposure to solvent vapors from trichloroethylene and n-propyl acetate at the Western Electric Company plant, Dublin, California. The Western Electric Company is a manufacturer of telephone trans mission equipment of all tyres. Approximately 5C0 people (AGO in pro duction and ICO in administration) v;ork in the plant during two full shifts, and about 20 to 30 persons are employed in the section of the facility described in the health hazard evaluation request. _ III. BACKGROUND HAZARD INFORMATION A. Standards Three potentially toxic substances were found in the place of employ ment. All three agents have established Federal standards which are promulgated by the U.S. Department of Labor (Federal Register, Part II, Vol. 37, No. 202, Section 1310.93, Tables G-l and G-2). Substance Federal Standard Trichloroethylene.......................... r.;t-. ........ 100 ppm* N-Propyl Acetate................................................... 200 ppm _ Toluene................................................................... 200 ppm B. Toxic Effects There is ample literature on the toxic effects of trichloroethylene (TCE) on man. From studies performed on levels of TCE in blood, it has been observed that arterial levels are much higher than venous levels because TCE, being very fat soluble, is rapidly absorbed from the blood stream.* Trichloroethylene is rapidly absorbed through the lungs, and following absorption, the compound is metabolized to trichloroacetic acid (TCA) and trichlcroethanol (TC-CH). Trichloroethanol is the most toxic metabolite *ppm - parts of vapor per million parts of contaminated air by volume at 25C and 7G0 run of Hg pressure. The standard is based on a timeweignted average for an eight hour per day (40 hour per week) exposure. SL 034158 Page 6 - Health Hazard Evaluation Report 72-74 of TCC. Both cerpounas are conjugated with glucuronic acid and ex creted from the body in the urine. Other possible metabolites of TCE include urocholalic acid, monochlcrcacetic acid, and chloroform. Stewart end his associates e.-pcsed human volunteers to 200 parts per million (ppm) of TCE in one stuey.^ TCE blood levels reached a maximum rcacir.c after 2 hours, fell to '2/3 of this level after 3 hours, and 20 minutes after exposure had terminated, fell to 1/6 of the ori ginal maximum concentration. Analysis of expired air samples from the volunteers after a period of 5 hours of no exposure showed that TCE was barely perceptible. Retention of metabolites has teen estimated to account for over 56% of the TCE that is inhaled. Metabolite retention can be broken down into the following: 7 - 272 7CA, 22% TC-OH, 22 - 45% urocholalic acid, end possible trace amounts cf monochloroacetic acid and chloro form. Browning reviewed the histopathological changes of chronic TCE poisoning in animals.' The finding included such changes as liver inflammation and cirrhosis, enlarged spleen, glomerular and tubular lesions of the kidney involving capillary dilatation and white blood cell infiltrates, emphysematous and inflammatory effects in the lungs, and hyperemia, edema, and small hemorrhages in the cerebrum and mar gins of the cerebellum. Kleinfeld^and Tabershaw repented 4 cases of fatal human exposure in one report.3 No gross anatomical changes were noted during autopsy other than a general visceral congestion. Other reports of fatal TCE poisoning ha.e also been reported, and post mortum findings include pulmonary edema, cardiac dilatation, Penal congestion, and vascular congestion of the brain.' Browning attributes deaths from TCE exposure to ventricular fibrillation or standstill and to acute pulmonary edema. In animals, TCE is a narcotic and anesthetic capable of causing complete unconsciousness. Browning reports almost immediate anes thesia in rats breathing 4,830 ppm cf TCE and that 3,000.ppm will produce complete anesthesia over a short period of time.' The effect of TC-CII on guinea pigs has been shewn to be much greater than the effect of TCE when measuring depression of the spinal reflex and elec trical excitability of the cerebral rotor cortex.^ It has also been shown that ethanol potentiates and attenuates the effects of TCE as determined by EEG measurements.^ Grandjean found that by exposing rats to 400 ppm of TCE for 6 hours per cay, 5 days a week for 44 weeks, TCE did not affect learning or intelligence in rats but decreased their "neuromuscular efficiency. .7- SL 034159 Page 7 - Health Hazard Evaluation Report 72-74 In hurans, TCE has been reported to cause EKG.changes of dis turbed sympathetic nerve control in as many as 1/3 of the subjects tested. Arryhthmias and even cardiac arrest are reported when using TCE as an anesthetic. EEG effects and reversible memory disturbances have been reported in cases of acute TCE poisoning.7 Optica! dis turbances such as decreased general vision, constriction of visual field, and diminished optchinetic fusion were reported in human volun teers exposed to 1,000 ppm of TCE for 2 hours. Chronic exposure to TCE can lead to contact dermatitis and chemi cal burns of the skin, cornea, and conjunctiva. TCE is a potent ir ritant of the upper respiratory tract and can cause slight to moderate eirphysema. Macrocytic anemia has been associated with some cases of intoxication. In high doses, TCE causes narcosis, with an initial excitatory phase. Stewart and his associates exposed 10 human volun teers to 100 end 200 ppm of TCE for time periods ranging from 1 hour to a 5 day work week.2 At 200 ppm, untoward subjective responses were mild, inconsistent, ard of doubtful significance. There was, how ever, sensations of mild fatigue and sleepiness in 5 subjects during the 4th and 5tn consecutive days at an exposure level of 200 ppm of"TCE. The following biological tests were performed on the subjects and found to be normal: C.D.C., E.S.R., total serum lipid, total serum pro tein, serum electrophoresis, SCOT, SGPT, urinalysis for urobilinogen, TC-0H, and TCA. Also normal were the results of the Romberg test, heel-to-toe, finger-to-nose, Crawford manual dexterity, and Flanagan coordination and inspection tests. __ _ --' Chalupa and his associates report that the greatest implication for adverse behavioral responses to acute exposures of TCE is in pre- - disposing an individual to an accident.' Minor post-intoxication symp toms are headache, vertigo, and insomnia. Memory may be affected for a year or more following acute high level exposure to TCE, especially as measured by mechanical memory tests. ------ -- -- Salvini and his associates exposed 6 human subjects to 110 ppm of TCE for two 4-hour periods separated by an 1 1/2 hour resting ----- interval.^ Subjects were tested with a perception test using tachistoscope presentation, the Eschsler Memory Scale, a complex reaction time test, and a manual dexterity test. Statistically significant decreases in performance by the subjects were noted on all tests, with decreases being greater on the more complicated tests. Salvini concludes that since the TCE exposures were close to the threshold limit value (TLV) of 100 ppm for the compound, it is possible that exposures at the TLV level may well be capable of adversely affecting psychophysiological efficiency. SL 034160 Page 8 - Health Hazard Evaluation Report 72-74 Toll-ore is a milder central nervous system depressant than is trichloroethylene. Toluene produces mild fatigue, weakness, confusion, ano parusthesia of the skin at 200 ppm for eight hours of exposure. At higher concentrations, extreme fatigue, rental confusion, nausea, head ache, and dizriness occur. Exposures to levels of 50 to 100 ppn. have repeatedly failed to cause any effects,10 Very little literature on the effects of n-propyl acetate on man is available. The compound is similar to other simple esters, causing mild skin and mucous membrane irritation and mild.central nervous system depression at levels considerably above 200 ppm.'1 HEALTH HAZARD EXUDATION A. Initial Visit - Observational Survey -- On September 1, 1S72 NIOSH investigator Melvin T. Okawa conducted _ an observational survey of the l.'estern Electric Company plant i:i Dublin, California. Representatives of management present during the observa tional survey were Plant Process - Conditions of Use: The printed wiring board processing area was designated in the hazard evaluation request as the section of the plant where exposures to solvent vapors wore occurring. Here,"pointed wiring board units under go a series of hand and mechanical soldering, fluxing, spraying, and washing operations before they are ready for final distribution. First, the board units a^e sent through an automatic mass solder machine (see figure 1). The soldering and washing steps are automatic, and the operator is responsible for introducing and removing the board units. Flux is applied, and the units continue on a conveyor through a solder "waterfall" and a trichloroethylene wash. One erployee can operate the machine and two of them are in the general area. For the most part, the mass solder machine is enclosed and local exhaust venti lation is provided at th? TCE wash point. However, it would not be con sidered as a closed system, and TCE vapors can escape into the atmosphere. At the end of each shift, the operator is responsible for cleaning the mass solder machine. During an operation that takes about 20 - 30 minutes to complete, the worker soaks a rag with TCE and wipes over most of the surface a"ea of the machine. Once a week, the cleaning eperation is more thorough, and the cleaning time is extended to one hour. Protective gloves are worn by the worker, but respirators are not. The operator is generally at the machine for an entire shift, but it does not run con tinuously. The day's supply of board units regulates the length of time -7- SL 034161 Page 9 - Health Hazard Evaluation Report 72-74 the machine is in operation. The board units are taken out of the processing area and undergo a series of modifications in the back assembly area before they ere returned. The units are brought to the two spray booths in the processing area. The booths are positioned at the east and west sides of the fa cility (sea figuies 2 and 2). On the east side, an additional spray teeth was being installed for future use. The worker loads four board units into a holder, sprays them with a lacquer (n-prepyl acetate and toluer.c), and unloads them onto a large drying rack. The drying rack is illustrated in figure 2. The spray booths are equipped with local exhaust ventilation and the worker is required to wear an organic vapor respirator. Because of the existing control measures, worker exposure to solvents seemed minimal. However, spray booth operators remove their respirators frequently as there are break periods between fresh racks of board units, and they receive exposure to ambient levels of solvents. It takes these workers about 10 - 15 minutes to complete a rack of board units. A washing or cleaning booth is located next to each of the spraying booths. With a brush dipped in TCE, the worker scrubs and cleans the board units inside"the hood. The TCE is contained in a small pan and is replenished from a safety container located in the hoed (see figure 4). Each washing booth is equipped with local exhaust ventilation anc the worker is required to wear an organic vapor respirator. TCE vapors become airborne because the solvent is readily splashed outside of the hood when the worker'becomes careless. Vapors also become airborne from the units left in the drying racks since they are not dried for a long enough period inside the hoods. Cecause of the control measures, workers are exposed to minimal amounts of TCE while they are using the hood. However, like spray booth operators, these employees remove their ins pirators during the frequent break periods between fresh racks of board units. The board units are then sent to the testing area for inspection. Some of the testers are seated at tables located 15 - 20 feet from the booths and drying racks (see figure 3). The majority of complaints con cerning solvent vapors are voiced by employees in the testing area, Dy interviewing these employees, it was discovered that drying racks can accumulate between the booths and the testing area. The employees feel that they suffer nore symptoms whenever the drying racks accumulate in the area. Approximately 10 employees work in the front sections of the testing area for a full shift. B. Environmental Evaluation An environmental survey for airborne concentrations of trichloroethylene, n-propyl acetate, and toluene was conducted on three separate days ($c>-.ember 13, December 7, 1972, and February 1C, 1973) by HIOSH investigator Melvin T. Okawa. /> SL 034162 Page 10 - Health Hazard Evaluation Report 72-74 Personal breathing zone samples were collected with MSA Model G battery powered vacuum purps wnich were u$ed to draw air through special glass sampling tubes containing activated charcoal. The sailing i.ethcd using charcoal tubes for solvents was developed by NICSH. The purps were hocked to the worker's lelt end the charcoal tube was attached to his lapel. The sampling rate was maintained at 1.0 liters per minute and the sampling tir.es ranged from 10 - 22 minutes in length. Workers were told to perform their jobs normally, and representative samples were collected. After the sample was collected, the charcoal tube was sealed and sent with the others tc HIOSH laboratories in Salt Lake City, Utah. Analysis of the charcoal was performed by the standard analytical method developed by fix OSH. The solvents were desorbed from the charcoal with carbon disulfic'e, and an aliquot of the solution was injected into a gas chromatograph. Solvent concentrations were assayed from the recorded curve. Results: -- The results from the environmental surveys of the Western Electric plant are contained in Table 1 and summarized in Tables 2 and 3. Nine breathing zone samples were collected on'employees spraying board units with a lacquer containing n-propyl acetate and toluene. The NPA concentrations ranged from nondetectable (0) to 32 parts per million (ppm) and the toluene levels" were between 0_- 12 ppm. The average concentrations for NPA and TOL respectively were 15.2 and 6.0 ppm. Although spray booth operators were not working with trichloro ethylene (TCE), the levels ranged from 13 - 40 ppm (average concentration 25.3 ppm).in the 9 samples collected. Since respiratory protective de vices are mandatory while spraying, these solvent levels do not represent the true worker exposure. The levels would represent work exposure without respiratory protection and with continuous spraying. Regardless of the con ditions of the exposure, the levels of NPA and TOL do not present health problem to the spray booih operators. The TCE levels were slightly higher, but evidence from past research indicate that the concentrations would not constitute a health hazard. The mean values or levels of TCE by type of-operation is summarized in Table 3 for the day of February 16, 1973. On this day, MI OSH physicians visited the plant to collect urine specimens which were analyzed for TCE metabolite levels. Three samples were collected, and the average TCE concentration was 29.0 ppm. This value did not differ much from the overall average. Twelve breathing zone samples were collected on employees washing board units with TCE. The NPA and 1QL levels ranged from 0-6 and 0-2 ppm respectively. These levels were insignificant. The TCE concentrations were from 6-82 ppm (average - 39.0 ppm). The TCE // SL 034163 Page 11 - Health Hazard Evaluation Report 72-74 values represent exposure of wash booth operators while they are cleaning board units in the absence of respiratory protection. Since respirators must be worn by wash booth operators while they clean board units, the TCE levels do not represent a true exposure, but are an indication of the amount of TCE vapors that become airborne. Six samples were collected on February 16, 1973. The average TCE value was 48.3 ppm which did not differ from the overall average (39.0 ppm). Twelve breathing zone samples were collected on workers in the testing area. The NPA and TOL levels ranged respectively from 0-21 and 0-6 ppm. These airborne levels were insignificant. TCE concen trations ranged from 8-44 ppm with an average of 24.4 ppm. Six samples were collected on February 16, 1973, and the mean level of TCE was 29.3 ppm. This value did not differ significantly from the overall average. Six samples were collected on mass solder machine operators. Only a trace of HPA was found and TOL was not detected. TCE concen trations ranged from 33-87 ppm with an average of 44.0 ppm. Repeated human exposure to these levels of TCE are marked by an absence of any permanent adverse health effect. -However, in view of the fact that the TCE bath is enclosed and ventilated, there is more TCE leakage than one would expect. Four samples were taken while solder machine operators cleaned their equipment. UPA and TOL were not detected. TCE levels ranged from 30-106 ppm with an average of 70.5 ppm. In terms of the Federal standard, which is based on a time-weighted average over an eight hour day and a 40 hour week, these TCE levels are not excessive since workers clean their machines on the average for 20-30 minutes per day. One sample showed a level of 106 ppm of TCE. This value represents an excursion above the 100 ppm standard which is allowable as long as it is balanced by periods of exposure below the 100 ppm level. In terms of toxic effects, it is unlikely that workers would suffer any permanent adverse health effects from such a short-term exposure, but from the standpoint of sound industrial hygiene practice, the present cleaning procedure is not recommended. A less toxic solvent plus respiratory protection is recommended, C. Medical Evaluation On December 7, 1972 fllOSH physicians Drs. Bodner and Ellison Interviewed 24 people working in the printed wiring board processing area to determine: (1) whether there was any consistency in the symptoms reported, ./^ SL 034164 Page 12 - Health Hazard Evaluation Report 72-74 (2) incidence of corplaints, and (3) seriousness of complaints. Of special interest was the incidence of weakness, nausea, vomiting, and other serious symptoms. Of the 24 people interviewed, 22 were women and 2 Ren. Their aces ranged from 21 tc 52 years with the mean and median at 37 years. All but three workers had sere complaints about their working conditions. The numbers end the percentages of people who reported symtoms is listed tele.'#: 17 reported nausea (70.8") 13 " headache (54.2") C " dizziness (33.32) 6 " throat irritation (25.02) 6 " nose irritation (25.02) 6 " fatigue and drowsiness (25.02) 5 " eye irritation (20.32) 2 " dermatitis (8.32) 1 " numbness (4.22) 1 " chest tightness (4.22) 1 " anorexia (4.22) 1 " abdominal pain (4.22) No one required hospitalization due to these symptoms, but 4 people saw either their own or a conpany physician or nurse. All the workers felt that their symptoms were relieved completely when they had left the work environment for several hours. On February 16, 1973, NIOSH physicians Bodner and Polakoff returned to the plant for further medical studies. Eight_hour urine samples were collected from 20 workers exposed to tri'aloroethylene and from 9 controls.-- After being preserved with thymol and refrigerated, these sampleswere sent to NIOSH laboratories in Cincinnati, Ohio, and were analyzed on February 20 - 28, 1973. The specimens were analyzed for metabolites of trichloroethylene, trichloroacetic acid and trichloroethanol, by the method of Tanaka and Ikeda (British J, of Industrial Uadi cine-,-2*--- 214, 1968). Creatinine was determined by the Autoanalyzer I standard method, a modification of the classic Jaffie procedure. Urine specific gravities were determined using a refractoneter. Three hundred determinations-v;ere performed including standards and blanks. Urine specimens were treated before spectophotoi^atry by the method oi Frant and V.'estendorp (Archives of Ind. Hygiene and Occupational Fed., 1: 308, 1950). Results have been expressed in terms of milligrams (mg) of metabolite (TCA or TC-CH) per liter of urine corrected to a specific gravity of 1.024. Results reported in the literature as mg/1 of a spot urine sample are not reliable because of the variation in urine concentration during the day. Results have also teen expressed in terms of mg of metabolite per gram of urine creatinine. Correlation studies on the two reporting methods and their relationship to airborne TCE levels have not yet been completed. /3- SL 034165 Page 13 - Health Hazard Evaluation Report 72-74 The tine of the work week selected for the urine sample is imoortant. In a recent study reported by Grata and his associates, the rates of ex cretion of TCA and TC-Gii were followed in humans exposed to 170 ppm of trichloroethylene in exposure chambers.^ The authors conclude that TC-OH is rapidly excreted in urine following exposure and readies a peak within 3 hours follcwing exposure. On the other hand, TCA excretion dscs net reach a peak until a-2 - 69 hours after exposure. Thus, TCA in Friday urines represents cumulative weekly exposure but net on the day sampled. However, TC-OH concentrations represents exposure during the day the sample was collected, and only residual excretion from exposure on previous coys of the work week. Ogata and unpublished data from NIOSH have shown a linear relationship between air levels of trichloroethylene and urine TC-OH collected after the v.*ork day. '2,13 Urine samples were collected cr. a Friday. Results: Tables 4, 5, 6, and 7 summarize the data obtained frem the-analysis ef urine samples collected from 20 exposed workers and 9 controls at the Western Electric Ccrpany plant. Control samples (Table 5) show values of-- TCA from undetectable to 29 ng/1 or 24 mg/gram creatinine. TC-OH values shew a range of undetectable to 27 mg/1 or IS ng/g creatinine. The lower level of detection is about 2 mg/1 with considerable variation below 10----mg/1. Controls from a previous NIOSH health hazard evaluation (RHE 72-84) showed values for both metabolites averaging less than 2 ng/1. This finding Indicates that control subjects at Western Electric had some exposure to TCE. The findings contained in Table 5 for post work samples where mean values for TCA and TC-CH were higher than pre-shift levels substantiates this conclusion. Also, from Table 5, control subjects with initials PP, AB, and LE were NIOSH personnel and all their pre-shift TCA and TC-OH urine levels were undetectable. Table 4 contains the TCA and TC-OH~values for exposed individuals. The data is summarized in Table 6. For exposed individuals, the range of TCA levels was 17 - 195 mg/1 or 11 - 145 nig/g. The_levels were ele vated above the values found for the controls and were in the same general range as found in workers in the previous hazard evaluation conducted by NIOSH. The average pre-shift TCA level was 66.5 mg/1 or 50.6 mg/g. The post work average was 70.6 mg/1 or 53.1 mg/g. The post work average showed a slight jump, undoubtedly indicating the-additional accumulation of TCA on Friday for the week. Trichloroethanol values ranged from 38 - 121 mg/1 cr 22 - 111 mg/g for pre-shift and 2 - 267 or 52 - 179 for post work levels. The respective pre-shift and post work averages were 78.1 mg/1 or 58.4 mg/g and 137.0 mg/1 or 103.2 mg/g. The TC-OH levels were elevated in the after noon samples, indicating exposure to TCE during the day. The range of TC-CH valfs was generally less than those found in the previous hazard evaluation where TCE exposures were between 37 and 78 ppm on an 8 hour tira-v.eightod average. This result would seem to indicate that on the average, workers at Western Electric were being exposed to slightly less quantities of trichloroethylene. Table 7 contains the ranges and means for TCA and TC-OH levels in high and low exposure groups. The high ex- SL 034166 Page 14 - Health Hazard Evaluation Report 72-74 posure group was arbitrarily selected to include those workers who were handling trichloroethylene directly (spray booth, wash booth, and rr.ass solder ncchir.e operators). The low exposure group was composed of workers in the testing end assembly areas. The ranges and means for TCA and 7C-CH levels between the groups are different but may not be significantly different On the avciegc, levels are more for the high exposure group, indicating a greater exposure to TCE. D. Conclusions The environmental data substantiate the fact that overall levels of trichloroethylene, n-propyl acetate, and toluene in the printed wiring board unit processing area are well within the limits defined in the Fe deral standards and veil below those levels generally thought to cause se rious clinical symptoms and adverse health effects. The levels of r,-propyl acetate and toluene in the ati esphere were not significant in terms of Lc-ing hazardous tc health. The airberre concentrations of trichloroethylene gene rally were less than 5C7 of the standard. Only one sample was collected where an excursion above the 100 ppm time-weighted average standard was recorded. This sample was collected during a short cleaning operation at the mass solder machine. Yet, from the medical interviews, a high propor tion of similar symptoms which correspond well with those found frer. intoxi cation with TCE, NPA, and TCL or a combination of these agents was voiced by workers in the area. The biological data in the form of levels of urine metabolites of TCF. indicated that workers were being exposed to TCE. At this time, no range of safe limits for urine metabolites of TCE have been established for an occupationally exposed population. The average urine trichloroethanol level of exposed persons at Western Electric correlate well with levels expected in workers Deing exposed to airborne concentrations of TCE below SOZ of the Federal standard. From a previous NIOSH study, workers being exposed to TCE in a range cf 37 - 7S ppm (based on an fi-heur timeweighted average) generally had higher urine trichloroethanol levels than those found in this investigation. E. Toxicity Determination Based upon the results of the investigation reported above, it is our determination that the substance trichloroethylene is toxic to workers in the printed wiring board_unit operations at the con centrations and conditions used and found at the time of this evaluation. Trichloroethylene is the only agent present is significant amounts throughout the work area and is thought to be the cause of the toxic manifestations of symptomatology occurring frequently, in workers during periods of heavy usage', although environmental levels detected were below the current Federal standard. The reported condition represents a hazard to the health of workers, although not considered serious since no permanent physical changes occur, and may also present the potential for a safety hazard due to the general reduction in motor function, ability to concentrate and increased likelihood of accidents on such occasions. It is also judged that the substances, N-propyl acetate and Toluene, are not potentially toxic at the concentration used or found. SL 034167 Page 15 - Health Hazard Evaluation Report 72-74 1) All spraying and washing operations v'ith printed wiring board units should be completed inside properly functioning ventilation hoods, Workers rust avoid spilling solvents outside of ventilation hoods. 2) Approved respirators should be used at the spraying and washing hoods and a respirator raintenace program developed. 3) To minimize exposure to trichloroethylene by wiring boanj unit testers, keep freshly washed boards in the washing booth until fairly dry ty collecting several beards in the booth and then transferring ther to the large drying racks rather than transferring each of them separately irr::cdia-,ely after washing. 4) All ventilation systems should be serviced regularly; frequent venti lation measurements should be made. 5) To minimize the exposure to trichloroethylene by mass solder machine operators, the ventilation system should be checked for adequacy of design, especially the capture velocities and.the presence of leaks. 6) For washing mass soldering machines, a less toxic solvent should be substituted for trichloroethylene. Also, approved respirators should be v/orn by the operators during the cleaning operation no matter what the type of solvent used. VII. REFERENCES 1) Browning, E., Toxicity and Metabolism of Industrial Solvents, Elsevier Publishing Company', London, ly'io. _ -- 2) Stewart, R., Gay, Erley, Hake, and Peterson, "Observations on the Concentrations of Trichloroethylene in Blood and Expired Air Following Exposure of Humans, " American Industrial Hygiene Assoc~- Vol. 23, March-April, 1S62. 3) Kleinfeld, M. and I. Tabershaw. Archives of Irid. Hvo.-& Occupa.tie.nal Med. , 10: 134-41, 1554. 4) Mikiskova and Mifciska, "Trichlorcethanol in Trichloroethylene Poisoning," Brit. J. Industrial Fed., 23: 116, T966. 5) Desoille, J. et al, `Intoxication experimentalc aigue par le tri chloroethylene," Ardu^Ji^^Pr^f^ 23: 10-11, 1S62. 6) Grandjean, E., "Trichloroethylene Effects on Animal Behavior,',' Arch. Environ. Health, 28: 106, I960. 7) Chal upa, B. et al, "The Assessment of Electroencephalographic Changes and Memory Disturbances in Acute Intoxications with Industrial Poisons," Brit. J. Industr. lisd., 17: 238, 1960. /(r SL 034168 Page 16 - Health Hazard Evaluation Report 72-74 8) Kylin, B. et al, "Effect of Inhaled Trichloroethylene on the CHS," Arch. Envircn. Health, 15: duly, 1967. 9) Salvirij, H., Birtaschi, S., and f'. Riva, "Trichloroethylene in Com bination with C.'.S Drugs,'' Arch. Environ. Health, 20: April, 1970. 10) Patty, F.A., Industrial Kyg ier.e & Toxicology. Vol- Ii, Interscience Tut listers, Ii. V7,--ls< ,` pp Veto - 1229. 11) Gleason, et al, CT'^'^el Toxicoioiy of Commercial Products, Baltimore P 100, 1. .. 12) Larry K. Lowry, PH.C., KIOSH, (unpublished report). 13) Cgata, et al, Br. d. Ind. Led., 28: 386, 1971. 7 SL 0341&9 Table I. Concentrations Of Trichloroethylene (TCC) . N-ProDvl Acetate (NPA), And Toluene (TOL) In Breathing Zone Samples Collected At The Western Electric Company Plant- r Location Of Semple Date TCE (ppm)* KPA (ppm) TOL (ppm) 9688 9700 10595 9691 9694 10SS6 11605 11608 non 9CC6 10558 11002 11598 11600 11602 9692 9701 11604 11607 11610 "9U93 9699 1 lw/ 11005 11599 11601 11603 9698 11000 11606 11609 11612 9b 9695 10997 11613 11614 11615 H5T57 11005 11007 11008 Spray BoIoI th (west) li Spray BoIoI th (east) II II II II " Nash booItIh '(west") It It II II M Wash Booltlh (east) l II ll fearer (wIt est) II ^H II II II Tester (eIt ast) ll II II "l.ass bo IcIIier It It II II ' 0leaning hHass Sold. it ii 9/13 9/13 12/07 9/13 9/13 12/07 2/16 2/16 2/16 5/13 9/13 12/07 12/07 2/16 2/16 2/16 9/13 9/13 2/16 2/16 2/16 9/13 ' 9/13 12/07 12/07 2/16 2/16 2/16 9/13 12/07 2/16 2/16 2/16 y/13 9/13 12/07 2/16 2/16 2/16 " y/13 2/16 2/16 2/16 22,0 40.0 24.0 .24.0 13.0 18.0 38.0 17.0 32.0 rcrro 38.0 27.0 82.0 49.0 41.0 60.0 16.0 6.0 43.0 44.0 53.0 j5.u 9.0 19.0 32.0 19.0 17.0 16.0 14.0 '8.0 44.0 40.0 40.0 2370 29.0 26.0 39.0 87.0 60.0 90 30.0 47.0 106.0 16.0 7.0 32.0 n.o 20.0 12.0 9.0 3.0 6.0 2.0 13.0 6.0 20.0 6.0 N.D ** N.D. 21.0 7.0 1 u ----- 07----- 1.0 N.D. ff.D. N.D. N.D. N.D. N.D. N.D. N.O. N.D. N.D. N.D. 6.0 2.0 1.0 N.D. N.O. N.D. N.D. N.D. N.O. N.D. 6.0 ----- 2.&------ 6.0 N.D. N.D. N.D. N.D. N.D. N.D. mn * ru>* N.D. N.D. N.D. N.D. 1.0 N.D. 21.0 6.0 N.D. N.D. N.D. N.D. N.D. N.D. --TtO-------- Il * 1.0 N.O. N.D. N.D. N.D. N.D. N.D. N.D. N.D. N.D. to:------- --o----- N.D. N.D. N.D. N.D. N.D. N.D. *pprn - parts of vapor per million parts of contaminated air by volume at 25C and 760 nm of Hg pressure **N,D. - compound was not detected in sample /f SL 034170 Table 2. Ranges And Mean Values Of Trichloroethylene, H-Propyl Acetate And Toluene Cmcentrations By Type Of Operation In Samples Collected At The Western Electric Company Plant* Operation Spray Booth Range Kean Wash Booth Range Mean Testers Range Mean Mass Solder Range Mean Cleaning Mass Solder Range Mean Wo. Of Samples 9 12 12 6 4 TCE (ppm) 13-40 25.3 6 - 82 39.0 8-44 24.4 23 - 87 44.0 30 - 106 70.5 abbreviations same as for Table 1. NPA (ppm) ' NO - 32 15.2 NO - 6 0.8 ND - 21 2.8 ND - 1 0.3 NO 0.0 TOL (ppm) ND - 12 6.0 ND - 2 0.2 ND - 6 0.7 ND 0.0 ND 0.0 Table 3. Mean Values Of Trichloroethylene By Type Of Operation In Samples Collected At The Western Electric Company Plant On February 16, 1973 Type Of Operation Spray Booth Washing Booth Testers Mass Solder Cleaning Mass Solder No. Of Samples 3 6 6 3 3 TCE (ppn) 29.0 ------- 48.-329.3 62.0 61.0 'f SL 034171 Table 4. Concentrations Of Trichloroacetic Acid (TCA) And Trichloroetharol (TC-Gii) In The brine Of Workers Exposed To Trichloroethylene At The Western Electric Company Plant Worker W.G. Ml.lH. RI.I F. J.IIH. AI.I Vi. Cto.A. J.IIN. J.tlG. BI.I L. Pl.lQ. CI.tA. VI.tA. El.iS. ii J.IIV'. P1.F. -L. R. * FI.IE. H.1H. RH.T. Samole No. TCA (no/!)* TC-OH (mo/1) TCA (iro/q)** TC-OH (rf'/g) 1 A*** 1 *** 108 61 2 A 62 2 G 53 3 A 120 3 B 77 4 A 27 4 A 27 5 A 77 5 B 91 6 A 77 6 B 49 7 A Sh NO SAMPLE 6 A 57 8B -- 84 9 A 17 9 B 34 10 A ,, 156 10 B 215 tl A 60 11 B 86 15 A 26 15 R 26 16 A -53 16 P, 97 !9 A 58 19 B 63 20 A 27 20 B 78 21 A 38 21 B 72 22 A 74 22 B 67 23 A . -- - 72 -23 B 94 28 A 94 28 B 46 29 A 34 29 B 21 103 103 ?10>!6> 3- w 267 38 89 90 132 67 140 . 107 8) 116 48 104 res 186 51 82 83 169 . 95 131 73 -84"-83 126 75 125 51 153 38 116 )"21 125 48 109 67 64 71 1-27 47 so- 34 153 133 105 46 160 23 3) 27 SO 46 53 69 100 7 r 62 38 no 42 -- 84 7^ 77 15 35 T75 ' 196 26 54 26---- 28 25 66 40 48 11 46-------- 21 31 - 55 39 60 59 57 31 23 14 in - - 107 44 108 -- 79 169 ti 52 83 179 44 89 51 63 33 75 42 5538 90 32 74 74 84 32 76 *mg/1 - milligrams of r "tabolite per liter of urine corrected to a specific gravity of 1.024 **mg/g - mi 11igrams of metabolite per gram of creatinine ***A/B - A is AM sample and B is PM sample 30 SL 034172 \ Table 5. Concentrations Of Trichloroacetic Acid (TCA) And Trichlcroethrrol (TC-CH) In The Urine Of Control Subjects Collected At The Western Electric Company Plant Subject J.Y. P.P. L.L. J. G. M.J. A.B. N.A. L.E. V.B. Sarnie No. 12 A*** 12 B*** 13 A 13 B 14 A 14 B 17 A 17 B 18 A 18 B 24 A 24 B 25 A 25 B 25 A 25 B 27 A 27 B TCA (mn/1)* TC-CH (rq/1) 9 T3 8 27 KQ**** ND ND 8 5 20 6 27 5 15 4 18 49 8. _ . 5 ND ND 17 ND 3 11 29 ND ND ND 3 ND 2 10 18 ND TCA (nc/q)** TC-CH 58 5 18 ND ND ND 5 28 3 14 39 3 15 35 64 ND ND 17 ND 26 24 ND ND ND 3 ND ND 7 22 ND *mg/l - mi Hi grams of metabolite per liter of urine corrected to a spec gravity of 1.024 **mg/g - milligrams of metabolite per gram of creatinine ***A/C - A is AM sample and B is PM sample ****ND - the limits of detection are 2 mg/1 and 2 mg/g. Values of 2 or less are indicated as NO (not detected). There is considerable variation for values of 10 or less SL 034173 Table 6. Ranges, Keans, And Standard Deviations Of Trichloroacetic Acid And Trichloroethanol Levels In Urine Samples Of Control And Exposed Subjects. Collected At The Western Electric Company Plant* Control Group AM Sar.ples TSange"----Kean St. Dev. Pi! Samples Range Kean St. Oev. TCA (rq/1) ND - 9 3.1 2.9 ND - 29 10.3 9.2 TC-OH fmc/1) ND - 20 8.9 6.9 NO - 27 ' 9.4 11.5 TCA (mq/q) ND - 5 1.8 1.6 ND - 24 9.2 9.1 TC-OH (mq/q) ND - 9 4.9 3.5 ND - 18 6.2 7.4 Exposed Group Tyi Samples Range Kean St. Dev. PM Samples Range Kean St. Dev. ~ 17 - 196 66.5 - 41.1 21 - 215 70.6 42.3 38 - 121 78.1 25.5 32 - 267 137,0 48.8 11 - 145 50.6 36.0 14 - 196 53.1 38.8 22 - 111 58.4 26.2 52 - 179 103.2 38.2 abbreviations the same as for Table 5 Table 7. Ranges And Keans Of Trichloroacetic Acid And Trichloroethanol Levels In Urine Samples Of High And Low Trichloroethylene Exposure Groups* High Exposure fn=6) AM Samples Range Kean PM Samples Range Mean TCA (mq/1) 58 - 19G 103.5 61 - 215 93.3 TC-OH (mq/1) 73 - 106 96.0 84 - 267 169.3 TCA (mq/q} '40 - 145 79.7 34 - 196 77.3 TC-OH (mq/q) 51 - 109 72.7 63 - 169 128.7 Low Exposure (n=13) AM Samples Range Kean PM Samples Range Mean 27 - 94 50.5 21 - 97 60.1 - 38 - 121 67.6 82 - 169 121.0 15 - 79 37.8 14 - 77 41.0 22 -W 49.8 52 - 179 91.5 abbreviations the sane as for Tab.o G. High exposure group composed of employees working directly with solvents. Low exposure group composed of of employees in the testing and assenbly areas. 32^ SL 03^174 * Figure 1: Automatic Mass Solder Machine Figure 2: East Spray Booth and Drying Rack 43 SL 034175 Figure 3: West Spray Booth Figure 4: Safety Can From Which Small Pans Are Filled With Trichloroethylene 03^76