Document 6BwJ8g1j40Ygr7d67G9pzOOE9

f I 1 .SBESTOS y j J Here's an update on asbestos. By O S. Bajhans, P.Eng., Occupational Haalth Branch. Occupational Health . Engineering Services. Toronto, Ontario. for asbestos was published in the U.K. by the Minister o( Labour.9 This was taken from the annual list of TLV's There has always been an attempt published by the ACGIH:Iri 1965 The on the part of scientists to establish a British pccupational Hygiene Society hygienic standard for asbestos that is. | biologically most appropriate in limit (BOHS) formed a Hygiene Standard Committee.' This committee, after s ing the hazard. However, since nsbes- critical examination of ' the ACGIH i tos was established as a human standards, recommended'the Use of ; carcinogen, it has been difficult to the ACGIH standard for asbestos for j establish a no-risk level, either for the time being, until they: have estab ! occupational exposure or non-occupa- lished their own standaW. " ; tional exposure. There is always some In 1967, Cooper' observed that the ( small risk to health as long as there is ' TLV of 5 mppcf for asbestos rests on ; any airborne dust in the environ shakier evidence than most TLV's. * ment. ' His chief argument was that a large ' Nevertheless, an allowable exposure proportion of asbestos fibres have 1 level must be set and defined by an diameters below the resolving power : index based on the theory that expo of the light microscope used for > sure u|> to pertain levels can be toler- Impinger counts and are therefore not | ated without incurring undue risks.. counted at all. He further reported This article will olfer a critical review that asbestosis appeared in insulation workers who were, exposed to con centrations much below the time-. weighted average of 6 mppcf.- Lea* thart and Sanderson' also considered : the TLV of 5 mppcf to be too high. In January of 1968 the ACGIH issued the following statement: , . "A" limit to. 6 mppcf, based on . impinger samples counted by light-field techniques is satis factory to Control exposures to ' most forms of asbestos: Crocl- . dolite, however, has been shown . . . to produce- mesotheliomas ' in. . ' addition to the common ashes-.:,*: totic inflammations. Since no safe limit can 'be estalished for,, this form of asbestos at this time, until more definitive data - are obtained, it.is recommended ' that workers exposed to croci- . dolite be equipped with air- of the existing and proposed occupa- , tional and non-occupalional standards for asbestos. ' -. OCCUPATIONAL STANDARDS The occupational or work-environment level is normally referred to as a Threshold Limit Value (TLV) or Time-Weighted Average (TWA). These values refer to time-weighted concentrations for a 7` or 8-hour work day and 40-hour work week..They refer to airborne concentrations under which it is believed that nearly all workers may he repeatedly exposed day after day without adverse ef fect. In 1946, the American Goverrtmen-' tal Industrial Hygienists proposed that the TLV for asbestos dust be set at 5 mppcf (million particles per cubic foot), as determined from impinger samples.' This value was recom 0 mended by Dressen, Dallavalle, Ed wards, Miller and Sayers after a study of 5-11 employees in three asbestos > :: viy- i's V'ifj Plgt l. Response to qhryeohi^e.'asbestos ;cxjj6s.ure: . ,\'-J textile plants using ebrysotile asbes \.\ i ' ' '' tos.1 In 1960 an occupational standard - 3H73 u* v-: i II it c* T at OCCUPATIONAL HEALTH AND SAFETY TEXWU 008505 s-/ HOU 053384 supplied helmet?.- TEXTILE STUDY However, by this time, the Hygiene Standards Commit tee of the HOHS under the chairman.sht|> of Professor Lane bad already completed mi envmmmenUl and mmiteal alitfly at an asbestos textile factory in England, in which mvestigntitms were made of 290 of the men employed in the period of t933-l%ti.: The asltvslos dust concentrations to which different workers had been exposed varied from ! flbre/cc to 27 fthrvs/cc measured by the membrane filter (MK) technique in which the number of fibres greater than 5u in length were counted. The problem of relating prevalence of aslxtslosis with concentration and with duration of exposure was re solved by assuming that the cumula tive amount of asbestos remaining in the lungs from a given exposure is equally dependent on the dust con centration and on the duration of exposure to that concentration. Thus, the exposure of an individual was expressed its fibre-years/cc, that is the product of the average coneentra* lion during working hours and his , years of exposure. Rxposure ex pressed in this way w as compared to the prevalence of asbeslosis and a curve was developed." (Fiff.' tf. One criticism of this curve was the use of a continuous scale starting at zero. Doses which give zero response are never, in fad, known with abso lute certainty since the sensitivity of a measuring instrument in limited. However* the main conclusion from the curve was that for an accumulated exposure of 10(1 fibre-veam/vc, it is probable that the risk of being affected, to the extent of having the earliest clinically demonstrated signs, is less than. T. That is, 2 libres/cc for 5U years, 4 libres/cc for 2b.years or Iff fibresAc for off yenra, 4 fibrosAx for 25 years or 10 librcs/cc for Iff years. ACOIH In Httttlhc ACL Ml pm^tsvd a TLV of 12 fibres greater than fi um in length per cc by the MK teclmique or 2 tnppcf by the impinger technique. This was probably based on the work of Lynch, Ayer and Johnson* in asbestos textile plants where I mp|>vf (impinged was shown to be equal to 5.9 libres/ic. In 1970' the AttilH proposed a lower asbestos dost limit of 5 fibres>cr by tin* MK technique nd eliminated the impingcr standard. ; However, this TLV remained on the intended changes list until 1977 when it was first adopted as the TLV ami . continues to be the one today. This j' TLV, if continued, would result in an j. accumulated exposure of 2f>0 fibre- years/cc over 60 years and an extrapo should reduce the likelihood of die- lation of the curve shown almvc would eases (malignant and non-malignant). indicate that this would result in more resulting from exposure in excess of than 2% risk of contracting asbesto 30 years with very long latent periods.. ses. . ' The US. Government published the In 1972 NIOSH. recommended the following in the Federal Register, Vol. following criteria for asbestos dust** 36, No. 234, December 7, UI7I." "Occupational exposure to airborne 'The 8-hour time-weighted asbestos dust shall be controlled so . average airborne concent ration that no worker shall be exposed to of asbestos dust to which em more than 2.0 asbestos fibres per cubic . ployecs are exposed shall not centimeter (cc) of air based on a count exceed 6 fibers per milliliter of fibres greater than 5 micrometers greater than 6 microns in (> 5 um) in length determined by the length, as determined by the membrane filter method at 400-450 X membrane filter method at 400- magnification (4 mm objective) phase 450X magnification (4 millime contrast illumination,as described In ter objective) phase contrast Appendix 1; determined as a time- . illumination. Concentrations weighted average (TWA) exposure . above 6 fibres per milliliter but, for an 8-hour work day, and no peak , not to exceed 10 fibres per millil- concentration' of asbestos to which. itef, may be permitted up to'a workers are exposed shall exceed 10.0 total of 15 minutes in an hour fibres/cc greater than $ um as deter for up to 5 hours in an 8-hour mined by a minimum sampling time day." of fifteen minutes," /; . On June 7,1972" the OSH A promul- . Along with the above recommends- gated a standard which limits the 1 tion the NIOSH. also, issued several worker exposure to an 8-hour time- other statements: weighted average . (TWA) of five . asbestos fibres per cc of air; and the 7# ceiling limit of 10 fibres/cc. They also mentioned that effective July I, 1976, .* ; ICToncMtrat/on. <* Category , -vypec the 1972 rule would reduce the expo sure limit to an 8-hour exposure limit of 2 fibres/cc. Selikoff et al" criticised Negligible / -Vvp.fWH v-:r; the standard on. the basis that the Low/ ' \ Medium High. / . ,, MoO.'V-V*- ','.6v*r |0.O fibres are made of fibrils 300 lo 350 Angstroms in diameter and cannot lie seen with the > optical microscope, being far below the limits of its reso (1) The standard is amenable lution. to techniques that 'are valid, In 1973 the Hygiene Standard reproducible and available to - Committee reviewed the 1968 ROMS ' industry and governmental standard for chrysolite and recom agencies. It will be subject to mended that no changes be made at review and will be revised as: the present time, but the standard be necessary. kept under review." They also re (2) The recommended stan viewed the information on the results dard is designed primarily to of human exposure to airborne mo prevent asbestosis. For other tile asbestos with animal experi diseases associated with asbes ments. They recommended that the tos, there is insufficient infor standards for amosite be the same as mation lo establish a standard . those for chrysotile. to prevent such diseases includ- It was further recommended that - mg asbestos-induced neoplasms the following table (Table I) be used to by any all-inclusive limit other designate certain ranges o( dusti than one of zero. Nevertheless, a ness. safety factor has been included On October 9, 1975 the Federal in arriving at the concentration Register" proposed a standard of 0.5 level that will reduce the total fibres per ce for an 8-hour TWA (or body burden and should more 500,000 fibres per cubic meter) and adequately guard against neo likewise a reduced ceiling of 5 fibres plasms. per cc (or 5 million fibres per cubic LATENCY A ceiling value of 10.0 meter) (or any period not exceeding libres/cc that was not to be exceeded 15 minutes. was included lo reduce the possibility IHPR The proposed standard did not of the short-term heavy exposures to apply to the construction industry and asbestos that have been reported to separate rulemaking lo revise the cause mesolheliama. In addition, this asbestos standard for construction NOVEMBER DECEMBER. 197/ TEX 3474 tq0NU 008506 I HOU 053385 , i industry was plnnncd. The Insulation * Hygiene Progress Report" critically ' revieiVetl Hie. proposed OSH A stan dard and issued the following state : ment: contrast microscopy. Our study'' indi cates that it is not possible to monitor the levels at 0.1 fibres/cc reliably. CANADA In'* Canada there is no uniform standard, all provinces have air as determined liy tbe mem brane filter method of evalua tion at KKVSOOx magnification using phase contrast illuminalion. `'This recognition that the their own asbestos standards. An British Coin mbin "-The B.f. construction industry is unique nttempt is made here to summarize Government have had a standard of 6 Is highly desirable. Earlier data the provincial standards. - mppcf (impingcr) for a tong lime. on . the effectiveness of moni toring in the construction indus try {see Insulation Hygiene ' Quehci *--The standard to be ap- i However, they hnvc now their stan plied is 5 fibres/cc but the Beaudry .' dard apd recommended TtV of 2 commission has suggested a reduction ' fibres |>er cc greater than 5 urn in Progress Reports, Summer to 2 fibres per cc or the equivalent length for chrysolite and 0.2 fibres/cc 1973), have shown that few dust OnlnrtV-They followed the for crocidolite in tbe Second Draft counts are ever taken in this ACGIH recommendation until 1972 Amendments, Workmen s Compensa segment of the Industry. Thus, and then they lowered the standard to tion Board, industrial Health and Specification of procedures is of 2 fibres/cc for chrysotile mainly due Safety Regulations, February. 1976. ; much greater importance here. to the following: They have also mentioned a ceiling of Individual workers must be able - (1) The U K. has been using 5 fibres/cc for 16-minute exposure. to judge whether or not they are this standard since 1971. " This is it the ceiling level of 10 fibres/ working in a safe environment . (2) The NIOSH criteria docu- cc recommended by Ontario. , on the basis of materials and' ment recommended this limit ' Saakatchtimn.''--The province has a methods rather than dust (3) The toxicities of various. . TLV of 2 fibres/cc for all asbestos counts. types of asbestos is not well ' varieties. "As much of insulation is now understood and hence a built-in " ';Vot>a Sco(ia''-At present, the stan asbestos-free, work practices for . installation of new material can safety factor was needed,. dard is 5 fibres/cc but new facilities be developed that would lead to | a time-weighted average expo- | . sure less than that proposed in the new standard. With care, .A "- ..JSwifu**** . * !j - even ripout can be done safely* but special precautions must be taken. Wetting techniques have now been developed that would `allow removal of asbestos to be accomplished within the'pro- . posed regulations." . 2 fibre OSHAlnvited comments on i#v|rafutrafn v* sinn w,wi,iw ...i4'u *sy_ in y.\uqpn\iud ' 30^j8y ftV6[8 i ipproprialenesd and feasibility from' he asbestos industry. On February 4,' I[976" some 65 representatives from Companies and trade associations repjesenting manufacturers and pro cesses of asbestos products in the United States participated in a meet- phrARi-V' V - : ,'ri'Tt>ntrlo Min|8lry 6^*he EhylrohWanlkjf-&jpl4ridi guldeiln*.of.i`fg/m> Fur crocidolite the standard is 0.2 will be required to meet the standard ibg held in Washington, D.C. and fibres/cc. They also have a ceiling of 2 fibres/cc. overwhelmingly endorsed that the "2 value of 10 fibres per cc for a 15-. The Working Group on Antonionis'* fibre" level has been or can be . minute exposure. recognized the documented and stis- attained by.application of engineer , ii{5rrfa~-OmAprit 15,1975 Alberta peeled health hazards associated with ing technology but the proposed "0.5 officially promulgated the following asbestos exposures and recommended fibre" level is unnecessary, impractic- occupational health standards: a uniform early acceptance of a : aide and lacks medical justification, (A) For asbestos dust or maximum tolerable level of 2 fibres/ jin a letter-dated December 15, fibre, all forths;. . the time- ml., time-weighted average. The prac 1976*' to the OSHA, Dr. Finklea of the weighted average airborne con tical objective, however, should he to N.IOSH recommends that the OSHA' . centrnlion. shall not exceed 2 reduce asbestos dust in the workplace reduce the standard for occupational fibres greater than 5 micro to the lowest possible level. exposure to asbestos to 0.1 fihroa per meters in length per cubic centi- Feasibility of 2 fibiysh-v Sta tnlunf m Dr. Finklea said the previous : meter of air, as determined by A standard should not he promul ' recommendation of a 2 fibres/cc was ` the membrane filter method of gated on whether it is feasible to meet designed primarily to prevent aslies- . evaluation at 400-450x magni it or not. Almost anything is feasible losw since insullicient information fication using phase contrast if it is necessary. However, it is a then existed to establish a standard to illumination. ' worthwhile exercise (<> analyst* if I he prevent aslwstos-related diseases such (It) For asbestos dust or fibre, standard is feasible. U should also ho as. pulmonary, pleural and peritoneal all forms, the maximum (ceil-, realized that 2 fibres/cc is a TWA over neoplasms. The 0.1 fibre per cc recom ing) airborne concentration an 6-hoiir period. In other words some mendation in based on lowest con- shall not exceed 10 fibres excursion during the period ran be ccrStralion at which asbestos fibre? greater Ilian 5 micrometers in permitted, but the excursion is filmin' enn he monitored reliably using phase length per cubic centimeter of; to 10 lihres/cc. Now. if one suppose? l' I f * e' I 40 J TEXWU 008507 Bilsom Propp-o-PIast IIiiihIIc llie loiii'liL'st InitiiMic icq'uircnicuts wiIh liilsum I'mpp-o-l'lasl. No shaping ' tcquitcci, l<L\ul}-lo-ui'nr l'ropp-o-l'IasV; tlisnosilhit' pltmsnrc piv-l'orliicd... A thin phlstic flint uovci ink the , /'. .. acoustical lihers inalnlitinsthe'ping ' shape. .Severn! pnKulelh.ine plugs" ' Isiieli as I--A-K, Deci-Damp) icqmie considerable nuihling aiul shaping uhichcoukl easily imbedeolilniui- minis into the plug mii face. I'ropp-o- I'last plugs lenutin untouched aiul ' k irfM-Wi--'`3 hvuidiic. t'oml'i'i table, too, because" a llie\ lit any si/e ear amt the minute . ' afi pores in the plastic Him allow the plug . %:lto hirallle. liennimiieal eiunigh In ' ^ loss away niter each use. I'lopp-o-Plast. ins lIoDlilr.n.dViIsI 'pj oumsaobi 'lIeV .. ` a... .. 1 -h' Bilsom for your comfort llilsiml tnl u f o a I ioitaI!. IIn. i.. IIIINmIHinI oSun. ri.se t\.aolko il.lf.i.il,lust. im, .V, Ai 221191 I'Iidiic (70.1) 02(1,'t'tsu 'Mmm that a worker is exposed to 10 fibres/ cc for 16 minutes he tfould he exposed to 1.7 fibres/cc for the rest of his shift, i.e. 6 x io 465 X 1.7 - 480 x 2. Lcmcu et aP4 showed that more than 50% of the operations in textile operations were able to meet the 2 fibres/cc limit and eohtrol technology to meet the 2F/cc level existing in nil operations in the friction product industry. A 9tudy has been carried out in Ontario to determine the technolog ical feasibility of the 2 f/cc standard" as is the Beaudry Commission in Quebec.*" The Ontario report" shown that the level of 2 fibres per milliliter is technologically feasible in the five major plants studied. COSTS Our studies in Ontario would seem to indicate that the industry is well aide to bear significantly in creased control costs without enor mous dislocations in the industry. We enforce asbestos standard.as strict as that presently used anywhere in the world. At the present time, it would seem that our asbestos using indus tries are economically healthy and perfectly capatde of working under the necessary constraints imposed upon them. Other Occupational Stn/ulnnl* (1) The BOHS has recommended a level of 0.2 fibres/cc for rroi idolite. " (2) The BOHS also gives the follow ing alternative indices for chrysolite asbesots." Respirable mass: -0.03 mg magnesium/m' * -0.04 mg SiO,/in* -0.10 mg ash/m* --0.12 mg asbestos/m' Thermal Precipitator: 25 ppcc greater than 1 um after incin eration. Impinger: 10 ppcc '; Uoyco Particle Counter: 2 ppcc greater than 4 um. It should, however, be realized that the above standards refer to condi tions in textile factories using chryso lite asbestos and the equivalents may not be applicable in other places. \ The joint ACGIH-AIHA Aerosol Hazards Evaluation Committee9* af ter reviewing various standards .in cluding the mass concentration con cluded that *'at present the only practical way to determine fibre concentration is by counting fibres which have been mounted on a suit able substrate so that they can be identified as individual fibres.'* environmental STANDARDS In 1-171 the Environmental Protection Agency, U.S. Government proposed emission standards concerning the following: (I) Emissions shall not exceed those which would be emitted from operations if proper engi- neering control had Ihhmi in stalled (i.e. fabric filter, cyclone gas cleaning devicesl. (2) Visible emissions of par ticulate. (3| Spraying of asbestos. (4) Use of asbestos for surfac ing or resurfacing of roads. The use of procedural standards am) visible emissions as the basis for eval uation for compliance with the stan dard are designed to minimize emis sion to the atmosphere. At about the same time the USA. through the Air and Industrial Hygiene Balwratory, California State iXqmitmcnt of Health, asks that the total fibre count downwind of an asbestos source not exceed 10 times the total fibre count upwind of that source. The Depart ment of Environmental Protection. State of Connecticut U.S. Environ mental Protection'Agency. had the problem under study, and required only that there In* iio visible emission or certain specified control equipment must lie used, e g. a bughouse, high energy serublwr, etc. Ontario has an emission guideline which is 5 inicrograms per cubic metre averaged over n half boor at point of impingement. This - *,, TEX 31'76 .. ^ TEXWU 008508 flic rnnronlrntion of asbes numerical relationship between the April' 6, 1973." The amendments tos itvenigml over a half hour result* emission guideline and the ambient thereto were proposed October 25; mg from the plume from any source, air quality guideline. The ambient air 1974.- - slack or vent. impinging on any recep quality guideline is the maximum The following are some of the high tor. a school, shopping ceHlre, ground. concentration, averaged over 24 hours, lights of this new document as it Hr., nl the lime when the wind Is to be found anywhere in the commu concent asbestos. Mowing from the source directly nity.. (1) The "no visible emissions" Imvnrd the receptor. Table II summarizes some of the air clause for the waste disposal of Since wind direction is variable and quality standards tii'force today. asbestos materials remains in . since more titan one source may The Final National Emission Stan effect V impinge on n given receptor at one dards for Hazardous Air Pollutants- (2) Asbestos mills are exempt time, the emission guideline is devel Asbestos and Mercury, promulgated from the requirement to wet oped to enrumpu&t these variables in by the U.S. Environmental Protection ' tailings when disposal site lem such a way that, if every source meets Agency, were published in the Federal, . tperatures are below 15* F. the emission guideline, the ambient Register of October 14, 1975s* and are . (3) Only asphalt concrete air quality guideline will not be effective as of that date. Initially the . ` manufacturing plants that use exceeded. Thus, there is no direct standards appeared m the Register of commercial'asbestos are af fected. . . (4) Local exhaust ventilation systems may be used during Have confidence in your test results: accuhaler 808" i . certain renovation operations. ' (6) Containers of asbestos .waste may display either an EPA or an.. OSHA warning label: ' ; . - the accurate personal sampling pump V {6) Clarification is given of . the definitions for "planned ' renovation" and "emergency re novation" operations. " ' 1 . (7) Wastes generated by op - erations that use sprayed-on materials containing less than 1% of asbestos by weight to insulate or fireproof buildings, structures, pipes and conduits are not covered by the new ruling, ohas REFERENCES 1. Rajhans, G.S.: Fibrous Dust--Hs Mea surement and Control, CfMM Bulle i tin.. pp. 900-910, August. 1970. 2. Dreesen, W.C.. DaHavaHe, J.M. Ed wards, T,l. Miller, J.W. Sayers. R.R.. Accuhaler 808 Personal Sampling System {including pump, orifices, 1. tube holder end calibration kit.l . Easom, H.F. and Trice, M.F., "A Study of Asbestosls In the Asbestos Textile Industry," Pub. Health Bus. No. 241, < PiffMW vO'un'i* n'eaturptvipnt * Eii'lv ulibralcd '.< RrMfenp. 1 oli/rne. Pplrpti'inn t)i|lilblCf. rml Ofltcr o><r*m<r nilmancts * Controlled inhalation Will not iterate when flow hhterteU ' . unttveriliablr i: |; ulH LOiV. 9rf;i'Sl9l,lr flow 'He: r.r. lo 96 cc min MESA approve! no. 2G 3026 . lor Mcthrme Atmospheres BASEEPA approval and CEflCHAR approval no 776504X | 1 Voi use w(fi Charcoal, 5hc# for Hyrltojci* Almosplreres OH low flow Onnior THifs - For additional information and your hee copy of the Charcoal Tube User Guide, cat! or write: * Washington, D C . 1938. 3. Addlngley, C.G.: Asbestos Dust and Its Measurement, Ann. Occ. Hyg., 9, 2., 1966. 4. Committee of Hygiene Standards of ! the British Occupational Hygiene So* clety: Hygiene standards lor chrysotlle asbestos dust. Ann. Occup. Hyg. 11:47-69, 1968. 5. leatharl, O.I.. and Sanderson. J.T., "Some Observations on Asbastosis." Ann: Occup. Hyg., 6: pp. 65-74, 1983. MDkk SCIENTFIC,INC. HOU 053387 8C^6u5seify*^vnfkcRicdiggee. anonOC^Phcre 3&x> 4250 te*e>r-?2-dOWAiDA'PWD 6. "Threshold Limit Values of Airborne Contaminants," Adopted at the 30th Annua) Meeting of the American Conference of Governmental Indus trial Hygienists, St. Louis. Missouri, MDkSului(kmv SCIENTIFIC tUKJLTD. reu'dcwnlncHst 86Cot>naml?tJ WmborneOcrtel.BH2I7PQ England Phone 202-87206 tee* 4?22<?C'M!La?-0- May 13. 1968. 7. "Hygiene Standards lor chrysolite asbestos dUsl," Ann. Occup. Hyg., Vol. 13, pp. 7-15, 1970. ` 0, Roach. S.A.. "Hygiene Standards for Asfrewne." Am*. QxC fry? 7-j? IX dpi 7-1X i970 TE* 3177 x'rr* .'f.n-xrv TEXWU 008509 9. Lynch J.R., AyBr H.E., Johnson D.C.: The Inler-relallohshlps ol selected asbestos exposure Indices. Amer.' Industr. Hyg. Assoc. J. 31:598-604, 1970. . . 10. Criteria for e Recommended Stan dard for Occupations! Exposure to Asbestos, U.S. Department of Health, Education, and Welfare, Public Health Service, Health Services and Mental Health Administration, Nation al Institute for Occupational Safety and Health, HSM # 72-10267. Wash ington. 0C, 1973. 11. Federal Register, 36,234. pp. 2.342-2, 343. Dec. 7, 1971. t2. federal Register. 37,22,142-11,144, Oct. te. 1972. 13. Setlkolf, I.J., Hammond. E.C. and H. Seldmsn: Cancer Risk of Insulation Workers In the United Slates Biolog ical Effects of Asbestos, pp. 209-216. international Agency for Research on Cancer, Lyon, 1973. 14. Anonymous. Review of Ihe Hygiene ' Standard for Chrysolite Asbestos Dust. Ann. Occup. Hyg., Vol. 16, p. 7. 1973. 15. federal Register. Vol. 40. No. 197, Thursday. Ocl. 9, 1975. 16. Anonymous. New Asbestos Standard Proposed, Insulation Hygiene Prog ress Report. Vol. 7, No. 3 arid 4. Winter. 1975. 17. Asbestos, p. 8-90, Feb. 1976. IB. Federal Register, Vol. 42. No. 130, Thursday. July 7, 1977. . 19. Rajharis. Q.S.. Q.M. Bragg and S. Morton: Asbestos Exposures in On tario--A Review, -Presented at the A.I,H. Conference New Orleans. May 24. 19R 20. Camite d elude Sur la Salubrite dans Hndustlre de I'amianle. pp. '262-285. April 1976. 21. Anon.. Asbestos Data Sheet. Occu pational Health Protection Branch; Ontario. Ministry of Health. August 1976. 22. Rajhans. G.S. and J.R. Assad: Engi neering Aspects of Asbestos Oust Control. Ann Arbor Science Publisher Inc. Ann Arbor (under Publication). 23. Report ol the Asbestos Working Group, Health and Welfare Canada. Feb. 15. 1976. 24. Lemen. R.A., J.M. Oement and R.E. Seiler; New Asbesloa Standard-- Feasibility of Compliance within Se lected Asbestos Industries. NIOSH Internal Report. 1972. 25. (Unpublished Report). Occupational Health Protection Br., Ontario Minis try of Health. August 1976. 26 Background Documentation on Eval uation of Occupational Exposure to Airborne Asbestos. ACGIH-AIHA Aerosol Hazards Evaluation Commit tee, Am. Ind. Hyg. Assoc. J. 36:91. 1974. -27. Anon.: Asbestos As a Hazardous Contaminant II. Ont. Ministry ol Envi ronment. Jan. 1975. 28. Anon.. Asbestos, p. 14, Nov 1975. You can tackle many OSHA noise measurements withthis one instrument GenRad's 1982 Precision Sound-Level Meter and Analyzer puts a Variety of OSHA-type noisemeasurement capabilities in the palm of your hand: ; 1. precision soundJevel measurement 2. octave-band analysis 3. peak (impact) noise measurement Just turn a knob and flip a switch to change functions. You don't need plug-in filters or other add-on accessories; i Precision microphone for IEC end ANSI Type 1 Measurements. It's removable lor remote mike positioning. Make octave-band f measurements bv se lecting 10 bend! Irom 31.6 Hz lo 10 kHz. z Digital display allows quick: accurate., error- free reading. ; The analog meter is calibrated linearly in 1<!B steps for easy re ' reeding. . . Set digital display lo hold feadout ol a spe- cific event or to up- ` ' date end hold the high- *. est leyet measured. Or set lo track the ambient levels. .' ,, For precision sound- ` level measurements, select weighting. A for OSHA. or B. C. or Met response. ' Select measurement ' range from 30 lo 140 dB m four 60-dB steps., Select meter response. ' slow of peak (impact! for OSHA. Fast and Impulse also select able. > Recharge batteries here. The 1982 is your single-instrument answer for OSHA and general-purpose noise measurements. Request complete details from GenRad, 300 Baker Avenue. Concord, Massachusetts 01742; (617) 369-8770 HOU 053388 GenRad ,1* 3'7' NOVEMBER 'DECEMBER. 1977 For more facia chela,17 on card. TEXWU 008510 " CITATION: .< '' SEND: PHOTOCOPY TOTAL PAGES CHARGES BD JOURNALUNBD JOURNAL BOOKCHARGES REASON UNFILLED: REQUEST REC'D BY: IN CIRC____________ MISSING____________ NOT REC'D__________ BINDERY DONOTOWH_____ OTHER___________ PHONE, MAIL . TWIX __ IN PERSON_________ HOU 053389 U* 3M79 TEXWU 008511