Document 2R9aM0k8Km22K3KNnLGYNo0Kb

FILE NAME: General Motors (GM) DATE: 1961 Aug DOC#: GM068 DOCUMENT DESCRIPTION: Internal Report - Inland Manufacturing Division Dayton, OH 12/-28^2001 14:54 Uiv. i. j;::;; ':2;: PAUL. REICH S MVERSiP.C. > 13052949806 K M 10 tiyM&lfcC 4 U M A N NU.ii'SO KOI? .1 v,* ! Inland Manufacturing Division Dayton, Ohio August 28, 29 and 30, 1961 1 Toluene Diisocyanate (TDI) Solvent vapor Trichloroethylene Cement Solvent Asbestos Dust ttolse No. 6157 Report! fey* j, vender Roest 12/28/2001 14:3a 1 ITr tl __ jS) ' U Industrial Hygiene Inland Manufacturing Division Dayton, Ohio At the request of Dr- R. L. Johnston an Industrial hygiene survey was made at the inland Manufacturing Division on August 28, 29 and 30, 1961. Pertinent natters were discussed with Dr. 8. I>. Johnston, Dr, B. Manner, Mr. H. I. Newsome and Mr. S. A. fright, who assisted in the survey. The Industrial Hygiene Department was represented by J. s. Vender Roast. r. CONCLUSIONS AND SUGGESTIONS Toluene Piisocyanate (TDll Atmospheric concentrations of TDI at crash pad and seat pad production operations were well below the permissible limit. No changes are suggested. Solvent vaner . Trichloroethylene Trichloroethylene vapor concentrations at steer ing wheel finishing operations were generally below the permissible' limit. Temporary peak concentrations exceeding the permissible limit were associated with removing the heels from the degreaserfi and indicate that a longer- drying time in the exhaust ventilated hoods is desirable. Trichloroethylene is used to flush the nozzle of one of the foaming machines in the crash pad produc tion department. Concentrations of trichloroethylene vapor at this operation were well below the permissi ble limit. Liquid trichloroethylene team the nozzle falls into a pail inside of a cardboard box on the floor, in the event that concentrations become objec tionable during closed operating conditions of colder weather, providing local exhaust ventilation to the floor receptacle should be considered. 00030 i * ' .O ' CXjU i. rOKZIO B'lOMSERG K '.EUAN ` .tf. - $ Cement- solvent: Aromatic hydrocarbon solvent vapor concentrations from cement used on bushings at boshing assembly ma chines were not excessive. Mo changes are suggested* AsbestOsDust Dust tests were below the permissible limit at forming, slitting and grinding operations associated with brake lining production. Copious dust deposits in the vicinity of tha forming presses indicate the need for .improved exhaust ventilation on these units. ! i Noise Sound measurements were made at several repre sentative operations designated by management* the measurements indicate that the suggested hearing dam age risk criteria are exceeded in several of the octave bands at some of the operations. Kernedial mea- i sures are discussed in the body of the report. 1 DISCUSSION Toluene Dlisocvanate (TOfl Crash pads and seat pads are produeed from polyurethane foam containing toluene diisoeyanate (TDX). Crash pads are produeed In Department 76, Building 28, on four foaming machines. Once the foaming machine is started, the necessary amount of foam is automatically released through a nozsle. After the proper amount of foam has been deposited between the fabric and backing, the parts are placed in a mold on a con veyor which carries them through an oven for curing. When the molds emerge from the oven, the parts are removed and padced for shipment after inspection. Slot exhaust ventilating duets were located below the noaxles of the foaming machines, along the con veyor and at the openings of the oven. Page 2 00C31 12/28/2001 14:54 PRUL. KtiCM & HTCK5 r C .C * ~r ra./io RRflMf.;iri 4 nlkma\ AL T/ Toluene Dlisocyanttte (Cont*^ Seat pads are produced on both sides of a wide conveyor in Department 7S, Building 28. Foam runs into the molds continuous ly from a nozzle on each aide of the conveyor, A thin sheet of plastic and a perforated metal lid are then placed over the mold in that order. After passing through the curing oven the lids are removed and the pads are taken out of the melds and placed on an adjacent conveyor. Plashing is trimmed from the pads prior to the final cure even. Two ten feet long exhaust slots, parallel to and above the center of the conveyer were located juet ahead of and behind the foam nozzles. a similar duet has been position ed above the conveyor where pads are removed from the molds and the molds are cleaned with a scraper and a compressed air jet, There was also a slot exhaust duct on the pad conveyor where padB are placed after removal from the molds. A flexible exhaust.duct, six inches in diameter, bad been provided for the scrap drum, near the nozzles, on each side of the conveyer. No toluene diisocyanate was detected in any of the tests made at various operations in both Departments, information was offered that low results from tests at these operations were also obtained by plant personnel. Ventilation appeared to be adequate and no changes are suggested. It was stated .that the prepolymer foaming method, formerly used, had been replaced by a "one shot" method? She changeover resulted In the elimination of objectionable fumes that emanated from the curing oven at times. Installation of a similar but larger seat pad production unit, located just south of the present unit, was in the final stages. Exhaust ventilating equipment appeared to be ample, al though it was not in operation. Permissible limit for Toluene Dlisocvtoate (TOI) The commonly accepted limit for TDI is 0.02 part per million parts of air by volume. Page 3. 00C3& 12/ 28/2001 cc.: f 14:54 PflULi REICH S fTRS.H.U * ijV M ^ f s t a o o r::i>7iO 8ffiM{.;5 4 NEWMAN i Results of rests - TOI Tcat va. TPI An p p m ______________________ Remarks Samples 1 through 3* inclusive, taken along south conveyor of the north seat pad installation with both aides of the conveyor in i operation. Building 28, Department 75. 1 Hone Detected Breathing zone of nan cleaving lids on noids after cutting plastic sheet with heat knife. Exhaust slot ten feet long over center of conveyor. 2 Bone Detected Breathing zone of nan cleaning molds with scrapes and air jet after pads had been removed near exit of oven. Twenty- four inch pedestal fan directed west causing gusty air flow. 3 Hone Detected Sample taken in breathing zone of man on north side of south trimming table. No local exhaust ventilation at this operation. Bo objectionable odors. i Sample 4 through S,. inclusive, taken at crash pud production oper ations in Building 27, Department 76. 4 Bone Detected Breathing zone of Bo. 4 foamer operator producing Pontiac Bonneville crash pads. Exhaust slot below nozzle and above waste box. General air flow 50 feet per minute from open monitor in north wall. 5 Bone Detected sample taken in breathing zone of Bo. 3 foamer operator. Local exhaust duct'in baek of nozzle. tteme Deteoted Breathing zone of men unloading crash pads from molds on conveyor near oven exit. Exhaust slots at oven exit end along conveyor where parts are removed. Page 4. 00033 12/28/2001 14:54 <!:C. rit. i-r-' `:2 PAUL. Reich & nrtxaif'.C. T X-1U-AC.7HJOCO iu?w wm-it i m m : solvent yap<j>r Triehl&roethvlens In Department 9, Building 20, the plastic surfaces of steer ing wheels are finished by processing diesi through trichloroethyl ene degreasers, two special types of dsgreasers are used. A Manpro Corporation Bax-L Model Ho. B-100, with a cylindri cal tank slightly larger than a 53-gallon drum* is the smaller of the two degreasers. Steering heels are placed en an *" shaped a m and lowered hydraulically into the vapor for thirty ascends. The wheels rotate on the upward and downward strokes and while they are suspended at the hottoe. An Aaust hood above the unit captures vapor iron the wheels where they hang to partially dry in the loading position. A very good vapor level is maintained by a cooling eoll of seven turns of copper tubing about one foot from the top of the taitic. a larger Detrex corporation degreeser, Model vs-800s, is used for continuously finishing steering wheels. The unit, which is soH x 30" x 3 0 % rests on the floor. Extensions of the tank sides and a top completely enclose the area above the tank with the exception of a 3-1/2* x 2' loading and unloading, opening on each of two sides. Surrounding the degreaser is a large platform which permits aceess to loading openings. Overhead conveyors carry wheels to and from the-loading positions. A continuous vertical conveyor, following a rectangular path inside the enclo sure, carries the wheels downward into the vapor, across to the opposite side and upward out of the vapor. The wheels rotate while in the vapor phase, some of the trichloroethylene evapo rates from the wheels as they travel through the exhausted enclo sure. Pace velocity of air flow into the loading openings varied from 50 to 75 fpm. concentrations of trichloroethylene vapor were generally be low the permissible limit at both degre&sers but there ware brief periods when the limit was exceeded. Peak concentrations were believed to be caused by residual trichloroethylene evaporating from the wheels after they were removed from the degreasers. A longer period of evaporation within the influence of the degreas er exhaust ventilation should reduce the amount of solvent releas ed after removal. Page 5. 00034 x c .' ext* t t x j i "- - r25. 2v7' `: - v- ftMl fe-ftMferV 4 |MA\ / / Trichloroethylene (Coated) I order to increase production, two nor Ma&pro degreasers have been installed on the Detrex loading platform. When these two units are put in operation# the area should he observed and a decision made regarding the desirability of a prolonged drying time. Dupont Triclene D was used in both areas. In Department 76, Building 27, the nozzle of the Ko. .4 foam er is automatically rinsed with trichloroethylene immediately after each shot. The 80 cc of solvent used suns into a five gal 1 lon open pail inside of a cardboard waste box. Seme of the tri chloroethylene drips and splashes onto the waste foam and card- hoard resulting in a large evaporative surface. The slot exhaust below the nozzle was too high to be effective but general condi tions of ventilation were favorable, concentrations of trichloro ethylene vapor were well below the permissible limit. Local ex haust ventilation on the waste receptacle may be necessary if 1 complaints indicate an increase in concentrations during colder weather. 1. Permissible Limit for Trichloroethylene The generally recognized permissible limit for trichloro ethylene la 100 parts per million parts of air by volume. Rsulta of Tests for Trichloroethylene Test Ke. Trichloroethylene in ppm ` Remarks 7 15-25 Breathing sene of operator of Haapro degreaser daring two IS minute peri ods of normal operation. Face velo city of hood varied from 0 to 100 fpm. a 145 Source zone test taken one inch a- 1 bove wheel Just removed from Manpro degreaser. Brief peak reading with rapid rise and fall. yx. r. 12/2B/20B1 rwuL.. K tlu^ o m tA J'i . v- Jsss * : r ;v K W I O f'ROM-'Ero 4 NEU* Rem i t s ef Tests for Trichloroethylene (Cont_*_d} I Test Trieb1eroethyIene Ho. In P W -- - Rcmarks 9 20-45 Breathing none of north loader of Detrox degreaser daring two 15 min ute periods of normal operation. The lower concentration prevailed most of the tine. 10 185 Very brief peak concentrations under sane condition as Test 9. These re sults seemed to be associated with dragout on some vfoeels. Pedestal fans In the area did not appear to effect the unit. t 11 3$ Maximum concentration found at breathing rone level immediately after norzle rinse at h o . 4 fowner, Air flow through open windows 50 fpm and gusty. Cement Solvent In Building 50, Department 72, two types of cement are used on bushings at bushing assembly machines. The cements are appli ed to metal and rubber parts of the bushings at the beginning of the assembly operation. The cement used at machines Ho. 2 and No. s consists of ssic s.C. Ho. 100 ftmsco solvent and 45% chlorin ated rubber, while the cement used at machines HO. 4 and Ho. 6 contains equal parts of S.C. Ho. 6 Amsco solvent and chlorinated rubber. The solvent portions of both cements are aromatic hydrocar bons, However, the S.c. h o . 6 has a much slower evaporation rate and other characteristics which differ from the S.C. HO. 100. The permissible limit for both of these substances in parts per million parts of air by volume 1 SOD. Concentrations of solvent vapor in the breathing zones of the machine operators and in the aisle west of the machines ranged from 25 to 50 parts per million. A temporary concentration of 200 ppm resulted when the operator of the no. s machine washed his hands and arms with the S.C. No. 100 solvent. On a time weighted average, ail tests ware below the permissible limit and no changes are required. Page 7 00036 : 12/ 28/2001 14:54 io- :. !?' ::t> PfttJLi REICH & MYERS.P.C. + lJk4*W3e rORZlO EiQMBERG & \MM iru<. i > Cement Solvent fCont *d) There is no practical method of resolving a mixed solvent vapor Into its various components to detersine the concentration of each. Asbestos post Brake linings are produced In Department 16, Building 11. The nix, consisting of asbestos, fillers and binders, is trucked to this department. Operations include forming the nix into slabs, baiting, splitting the slabs to necessary width and grind ing to specified thickness. The slitters and grinders had been provided with adequate local exhaust ventilation^ but there was no exhaust ventilation on the forming machines, one operates stated that without an ad jacent pedestal fan, the loading position would be untenable. Heavy accumulations of dust on surfaces in the area were noted. Although a dust test at this operation was below the permissible limit, the pedestal fans now lo use should be replaced by suit able exhaust ventilation, Mr. K. . Robinson, of this office, -made specific recommendations regarding the provision of exhaust ventilation on the forming machines, in a letter dated January 25, i960, to Mr. H, I,* Avery. Results of tests at slitting and grinding operations were below the permissible limit, Permissible Limit for Asbestos Dust The permissible limit is considered to be that of asbestos oven though it is recognized that other substances are included in the formulation. The permissible limit far asbestos is 5,000,000 particles per cubic foot of air. Results of Tests for Asbestos Dust Test particles of bust ----per CUbic Foot of Air ___________Remarks____________ 12 3,000,000 Breathing rone of operator of Dry Mix (forming) Press Ho. 509. Air flow gusty free pedestal fan blowing north. Area appear ed dusty. Page 0. 00037 i i I.S O' UUA rf: ^ 1WTl O. illli\JM ^ t x _j*L-rt_n-j f'WZIC iRCMBR*3 4 NEWMAN uj.&.'O hro.<_> y * y Results cf Tests for Asbestos Duet (CpntLd) Test So. PartieIsa Of Dost ,per Cubic Poot of Air n*rita 1-3 1000 *000 Brsathing zone of operator of slitter and Gardner Grinder in southwest c o m e r of Dpartaient 16, Pedestal fan directed west past operator. Local exhaust on machines. Id 1,000*000 Breathing sene of Blackman grind' er operator in northeast corner of Department 16. Air flow 500 fpo, eight inches from exhaust slot. i Noise I Sound measurements were made at certain noisy operations in \ dicated by management* Several measurements ware made at repre sentative bushing assembly, operations in Department 72* Building 50. various rubber and metal bushings are assembled rapidly by impact on a row of press-like machines. An overhead belt convey or moves the parts to large duet-like hoppers* two of tdtich sup ply each machine. Metal parts falling into these metal ducts produce the most noise When the ducts are empty. It would be possible to line the ducts or change the design to reduce the noise. However* the impact noise* occurring every 2-1/2 seconds, on each of the bushing assembly machines In only slightly quieter. }I Methods of attenuating impact noise of this type* and syntron Vibrator noise on hoppers, have not been developed. Noise at the Cumberland vinyl grinder In Department 1* Build ing 23* exceeded the tentative bearing damage risk criteria in six of the eight octave bands* with the noise predominating in the higher frequencies. A well-designed enclosure around this i unit would probably reduce the sound to acceptable levels. `One man tends the unit but he does not remain continuously at the ma chine. Mandrels* around which high pressure lines are braided* are straightened in a small machine in Department 13. Building 27. Page 9. OQOSSj A ' O ' exj u l m n o rfiOMCfftfi J HrHMAiy Noise (cont*d) Noise in the hearing rone of the operator slightly exceeded the criteria sectioned in three octave hands for most or the nandrels, hut frequently there are nandrels that 'cause louder high frequency noise. The operator Is the only nan in the vicinity. j i Since there are no practical methods to reduce the noise at some of these operations, and considering the snail number of people and the expense involved in building enclosures at others, ] it Is suggested that ear protection in the fora of ear plugs be ! provided the employs in question. i enclosures around the machine In the Braider Room have re duced noise levels below the hearing damage risk criteria, zt is believed that even better attenuation would be obtained If the openings were made as small as possible. Permissible Limit for Noise there is no generally accepted limit for noise in factories, A tentative hearing damage risk criteria, suggested by Bolt, Bersnsk and Newman, a group of noise consultants, may be found # in the following table of noise tests. It Should be pointed out that there is a strong move in the field to lower the level to BS db in the 30Q-600 and 600-1200 octave bands instead of the 94 now being suggested. Noise Level Measurements See Sable appended to this report. EXPLANATORY NOTES Method of Teats VOX samples were collected in a solution of acetic end hydro chloric aeid. Analysis was according to the method of X. Kareali, described in Analytical Chemistry, Volume 29, NO. 4, April, 1937. Tests for trichloroethylene were made with a Davis Halide Meter. Page 10. 00033 a , :i/i Klfl'lC JRCMifir. {NfWMAtJ i Method of Testa fcont *d) Solvent vapor concentration* were measured with a Davis Vspotester Model K-6, Molecular weight of the solvent was determined by the victor Meyer method, the instrument was calibrated by using a dynamic apparatus to produce known concentrations of airvapor mixtures, essentially the dynamic apparatus operated by continuously injecting the solvent into e predetermined moving stream of air which vaporizes the solvent and assures a constant supply of the mixture., Asbestos dust oantples were collected with an M.S.A, Midget mpinger with butyl alcohol as the entrapping liquid. Counts were made in accord with the procedure outlined in V.5. Public Health Bulletin Mo. 217. Measuremanto relating to noise were made with a H e m o n Hosnar Scott sound bevel Meter Type 410-B, serial No. 956. and octave Band Analyzer Type 420-A, serial No. 258. Production Rate Production was reported to be normal. Page 11, 00040 KWMI3H ? 9>:9W038 Ollii'J Dept, BIO. Bo. location and Remarks Over-all Noise Level Decibels c Frequency Analysis Decibels per Octave Band 20- 75- 150- 300 - 600- 1200- 2400- 480075 150 300 600 1200 2400 4800 9600 Tentative Hearing Dam age Risk Criteria (Bolt, Bsranek and Newman), 110 102 96 94 94 94 94 94 50 72 Impact noise Aten met ' al and rubber are join ed at No. 5 bushing as- senfcly machine, impact ! very 2-1/2 seconds. in bearing rone o oper ate. 112 SB 89 100 103 108 109 100 103 50 72 Same as above, except at machine n o . 4. 112 50 72 Byntron vibrator at bot tom o bushing parta hopper containing part No, 76516 (Innas shell). 96 SO 72 Above vibrator with hopper empty. 100 50 72 Above parta dropping into hopper chute. 112 SO 69 92 99 104 107 109 105 86 85 92 89 90 92 94 90 93 84 89 92 94 92 91 84 Page 12  wN Dept. Bide. Me. Over-all Molse Level Decibels c !1 j SO 72 Parts Ho. 764322 (outer stall) dropping Into empty hopper chutes at Chine do. 1. this happens from one to three times per day. 114 \ 27 13 Hearing zone of mandrel stralghtener operator. Exceptionally loud wire passing through 101- stralghtener. 110 27 13 Hearing cone level, be tween Mo. 1 and MO. 2 machines in Braider Boom. 95 23 1 Cumberland vinyl grind er - close to unit. 116 Frequency Analysis.. Decibels -per Octave Band 20- 75- ISO- 300- 600- 1200- 2400 - 480075 150 300 600 1200 2400 4BOO 9600 60 79 86 95 96 98 93 61 87 82 90 68 88 90 88 80 92 95 97 101 111 111 104 95 - _ .. % ' -T *=*5 ^ & n er? U* 1 r 35E 'i Page 13 c 1r->C, * C * i