Document 71Dm3my6pO7z9r8Mvmmm9E25R

ASBESTOS Here's an update on asbestos... By G.S. Rajhans. P.Eng., Occupational Health Branch, Occupational Health Engineering Services. Toronto, Ontario. There has always been an attempt on the part of scientists to establish a hygienic standard for asbestos that is biologically most appropriate in limit ing the hazard. However, since asbes tos was established as a human carcinogen, it has been difficult to establish a no-risk level, either for occupational exposure or non-occupational exposure. There is always some small risk to health as long as there is any airborne dust in the environ ment. Nevertheless, an allowable exposure level must be set and defined by an index based on the theory that expo sure up to certain levels can be toler ated without incurring undue risks. This article will offer a critical review of the existing and proposed occupa tional and non-occupational 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 be repeatedly exposed day after day without adverse ef fect. In 1946, the American Governmen tal Industrial Hygienists proposed that the TLV for asbestos dust be set at 5 mppef (million particles per cubic foot), as determined from impinger samples.' This value was recom mended by Dressen, Dallavalle, Ed wards, Miller and Sayers after a study of 541 employees in three asbestos textile plants using chrysotile asbes tos.-' In I960 an occupational standard for asbestos was published in the U.K. by the Minister of Labour. ' This was taken from the annual list of TLV's published by the ACGIH. In 1965 The British Occupational Hygiene Society (BOHS) formed a Hygiene Standard Committee.* This committee, after critical examination of the ACGIH standards, recommended the use of the ACGIH standard for asbestos for the time being, until they have estab lished their own standard. In 1967, Cooper' observed that the TLV of 5 mppef for asbestos rests on shakier evidence than most TLV's. His chief argument was that a large proportion of asbestos fibres have diameters below the resolving power of the light microscope used for impinger counts and are therefore not counted at all. He further reported that asbestosis appeared in insulation workers who were exposed to con centrations much below the timeweighted average of 5 mppef. Leathart and Sanderson5 also considered the TLV of 5 mppef to be too high. In January of 1968 the ACGIH issued the following statement: "A limit to 5 mppef, based on impinger samples counted by light-field techniques is satis factory to control exposures to most forms of asbestos. Crocidolite, however, has been shown to produce mesotheliomas in addition to the common asbestotie 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 crocidolite be equipped with air- Exposure (fibre years/cm^) Fig. I.Response to chrysotile asbestos exposure LAM 001312 tr OCCUPATIONAL HEALTH AND SAFETY fDPMC-17010 LAM 001313 supplied helmets.6 TEXTILE STUDY However, by this time, the Hygiene Standards Commit tee of the BOHS under the chairman ship of Professor Lane had already completed an environmental and med ical study at an asbestos textile factory in England, in which investi gations were made of 290 of the men employed in the period of 193.1--1966.: The asbestos dust concentrations to which different workers had been exposed varied from 1 fibre/cc to 27 fibres/cc measured by the membrane filter (MF) technique in which the number of fibres greater than 5u in length were counted. The problem of relating prevalence of asbestosis 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 as fibre-years/cc, that is the product of the average concentra tion during working hours and his years of exposure. Exposure ex pressed in this way was compared to the prevalence of asbestosis and a curve was developed." (Fig. 1) One criticism of this curve was the use of a continuous scale starting at zero. Doses which give zero response are never, in fact, known with abso lute certainty since the sensitivity of a measuring instrument is limited. However, the main conclusion from the curve was that for an accumulated exposure of 100 fibre-years/cc, it is probable that the risk of being affected, to the extent of having the earliest clinically demonstrated signs, is less than 1%. That is, 2 fibres/cc for 50 years, 4 fibres/cc for 25 years or 10 fibres/cc for 50 years, 4 fibres/cc for 25 years or 10 fibres/cc for 10 years. ACGIH In 1909 the ACG1H proposed a TLV of 12 fibres greater than 5 urn in length per cc by the MF technique or 2 mppcf by the impinger technique. This was probably based on the work of Lynch, Ayer and Johnson" in asliestos textile plants where 1 mppcf (impinger) was shown to be equal to 5.9 fibres/cc. In 1970' the ACGIH proposed a lower asbestos dust limit of 5 fibres/cc by the MF technique and eliminated the impinger standard. However, this TLV remained on the intended changes list until 1973 when it was first adopted as the TLV and continues to be the one today. This TLV, if continued, would result in an accumulated exposure of 250 fibre- years/cc over 50 years and an extrapo lation of the curve shown above would indicate that this would result in more than 2% risk of contracting asbesto sis. In 1972 NIOSH recommended the following criteria for asbestos dust."' "Occupational exposure to airborne asbestos dust shall be controlled so that no worker shall be exposed to more than 2.0 asbestos fibres per cubic centimeter (cc) of air based on a count of fibres greater than 5 micrometers (> 5 um) in length determined by the membrane filter method at 400-450 x magnification (4 mm objective) phase contrast illumination, as described in Appendix 1, determined as a timeweighted average (TWA) exposure for an 8-hour work day, and no peak concentration of asbestos to which workers are exposed shall exceed 10.0 fibres/cc greater than 5 um as deter mined by a minimum sampling time of fifteen minutes." Along with the above recommenda tion the NIOSH also issued several other statements: Category Negligible Low Medium High TABLE 1 Dust Concentration free 0-0.4 0.5-1.9 2-10.0 over 10.0 (1) The standard is amenable to techniques that are valid, reproducible and available to industry and governmental agencies. It will be subject to review and will be revised as necessary. (2) The recommended stan dard is designed primarily to prevent asbestosis. For other diseases associated with asbes tos, there is insufficient infor mation to establish a standard to prevent such diseases includ ing asbestos-induced neoplasms by any all-inclusive limit other than one of zero. Nevertheless, a safety factor has been included", in arriving at the concentration level that will reduce the total body burden and should more adequately guard against neo plasms. LATENCY A ceiling value of 10.0 (ibres/cc that was not to be exceeded was included to reduce the possibility of the short-term heavy exposures to asbestos that have been reported to cause mcsotheliama. In addition, this should reduce the likelihood of dis eases (malignant and non-malignant) resulting from exposure in excess of 30 years with very long latent periods. The U.S. Government published the following in the Federal Register, Vol. 36, No. 234, December 7, 1971." "The 8-hour time-weighted average airborne concentration of asbestos dust to which em ployees are exposed shall not exceed 5 fibers per milliliter greater than 5 microns in length, as determined by the membrane filter method at 400450x magnification (4 millime ter objective) phase contrast illumination. Concentrations above 5 fibres per milliliter but, not to exceed 10 fibres per millil iter, may be permitted up to a total of 15 minutes in an hour for up to 5 hours in an 8-hour day." On June 7,1972'-' the OSHA promul gated a standard which limits the worker exposure to an 8-hour timeweighted average (TWA) of five asbestos fibres per cc of air; and the ceiling limit of 10 fibres/cc. They also mentioned that effective July 1, 1976, the 1972 rule would reduce the expo sure limit to an 8-hour exposure limit of 2 fibres/cc. Selikoff et al" criticized the standard on the basis that the fibres are made of fibrils 300 to 350 Angstroms in diameter and cannot be seen with the optical microscope, being far below the limits of its reso lution. In 1973 the Hygiene Standard Committee reviewed the 1968 BOHS standard for chrysotile and recom mended that no changes be made at the present time, but the standard be kept under review." They also re viewed the information on the results of human exposure to airborne amosite asbestos with animal experi ments. They recommended that the standards for amosite be the same as those for chrysotile. It was further recommended that the following table (Table I) be used to designate certain ranges of dusti ness. On October 9, 1975 the Federal Register'" proposed a standard of 0.5 fibres per cc for an 8-hour TWA (or 500,000 fibres per cubic meter) and likewise a reduced ceiling of 5 fibres per cc (or 5 million fibres per cubic meter) for any period not exceeding 15 minutes. IHPR The proposed standard did not apply to the construction industry and separate rulemaking to revise the asbestos standard for construction NOVEMBER/DECEMBER. 1977 DPMC-17011 39 nV industry was planned. The Insulation Hygiene Progress Report"1 critically reviewed the proposed OSHA stan dard and issued the following state ment: "This recognition that the construction industry is unique is highly desirable. Earlier data on the effectiveness of moni toring in the construction indus try (see Insulation Hygiene Progress Reports, Summer 1973), have shown that few dust counts are ever taken in this segment of the Industry. Thus, specification of procedures is of much greater importance here. Individual workers must be able to judge whether or not they are working in a safe environment on the basis of materials and methods rather than dust counts. "As much of insulation is now asbestos-free, work practices for installation of new material can be developed that would lead to a time-weighted average expo sure less than that proposed in the new standard. With care, 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 OSHA invited comments on appropriateness and feasibility from the asbestos industry. On February 4, 1976" some 65 representatives from companies and trade associations rep resenting manufacturers and pro cesses of asbestos products in the United States participated in a meet ing held in Washington, D.C. and overwhelmingly endorsed that the "2 fibre" level has been or can be attained by application of engineer ing technology but the proposed "0.5 fibre" level is unnecessary, impractic able and lacks medical justification. In a letter dated December 15, 1976"' to the OSHA, Dr. Finklea of the NIOSH recommends that the OSHA reduce the standard for occupational exposure to asbestos to 0.1 fibres per cc. Dr. Finklea said the previous recommendation of a 2 fibres/ce was designed primarily to prevent asbestosis since insufficient information then existed to establish a standard to prevent asbestos-related diseases such as pulmonary, pleural and peritoneal neoplasms. The 0.1 fibre per cc recom mendation is based on lowest con centration at which asbestos fibres can be monitored reliably using phase 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 their own asbestos standards. An attempt is made here to summarize the provincial standards. Quebec-'1--The standard to be aj>plied is 5 fibres/cc but the Beaudry commission has suggested a reduction to 2 fibres per cc or the equivalent. Out a rt'o-"-Thcy followed the ACGIH recommendation until 1972 and then they lowered the standard to 2 fibres/cc for chrysotile mainly due to the following: (1) The U.K. has been using this standard since 1971. (2) The NIOSH criteria docu ment recommended this limit, (3) The toxicities of various types of asbestos is not well understood and hence a built-in safety factor was needed. air as determined by the mem brane filter method of evalua tion at 400-500x magnification using phase contrast illumina tion. British Columbia----The B.C. Government have had a standard of 5 mppcf (impinger) for a long time. However, they have now their stan dard and recommended a TLV of 2 fibres per cc greater than 5 um in length for chrysotile and 0.2 fibres/cc for crocidolite in the Second Draft Amendments, Workmen's Compensa tion Board, Industrial Health and Safety Regulations, February, 1976. They have also mentioned a ceiling of 5 fibres/cc for 15-minute exposure. This is Vi the ceiling level of 10 fibres/ cc recommended by Ontario. Saskatchewan----The province has a TLV of 2 fibres/cc for all asbestos varieties. Nora Scotia----At present, the stan dard is 5 fibres/cc but new facilities TABLE 2 LAM 001314 REGULATING AGENCY CALIFORNIA + Air and Industrial Hygiene Laboratory. California State Department of Health CONNECTICUT + Department of Environmental Protection, State of Connecticut ONTARIO Ontario Ministry of the Environment Air Resources Branch ASBES TOS-CONCENTRA TION STANDARD Total fibre count downwind of an asbestos emission source must not exceed 10 times the total fibre count upwind of that source. 30 ng/m1 (based on 30-day 'average sample) Interim guideline of 5 iig/m' For crocidolite the standard is 0.2 fibres/cc. They also have a ceiling value of 10 fibres per cc for a 15- minute exposure. Alberta '--On April 15, 1975 Alberta officially promulgated the following occupational health standards: (A) For asbestos dust or fibre, all forms, the timeweighted average airborne con centration shall not exceed 2 fibres greater than 5 micro meters in length per cubic centi meter -of air, as determined by the membrane filter method of evaluation at 400-450 x magni fication using phase contrast illumination. (B) For asbestos dust or fibre, all forms, the maximum (ceil ing) airborne concentration shall not exceed 10 fibres greater than 5 micrometers in length per cubic centimeter of will be required to meet the standard of 2 fibres/cc. The Working Group on Asbestosis-' recognized the documented and sus pected health hazards associated with asbestos exposures and recommended a uniform early acceptance of a maximum tolerable level of 2 fibres/ ml., time-weighted average. The prac tical objective, however, should be to reduce asbestos dust in the workplace to the lowest possible level. Feasibility of 2Jibres/cc Standard A standard should not be promul gated on whether it is feasible to meet it or not. Almost anything is feasible if it is necessary. However, it is a worthwhile exercise to analyse if the standard is feasible. It should also be realized that 2 fibres/cc is a TWA over an 8-hour period. In other words some excursion during the period can he permitted, but the excursion is limited to 10 fibres/cc. Now, if one supposes /in DPMC-17012 omioATiOMai hcjith awn <:4Cctv Bilsom Propp-o-Piast Handle the toughest hygiene requirements with Bilsom Propp-o-Plast. No shaping . required. Ready-to-wear Propp-6-Plast disposable plugs are preformed. A thin plastic Him covering the acoustical fibers maintains the plug shape. Several polyurethane plugs (such as E-A-R, Deci-Damp) require considerable molding and shaping which could easily imbed contami- ` nants into the plug surface. Propp-oPlast plugs remain untouched and hygienic. Comfortable, too, because . they fit any size ear and the minute pores in the plastic flint allow the plug to breathe. Economical enough to 1 toss away al ter each use, Propp-o-PIast is 100% disposable. Hilsoni International, Inc., 118(H) Sunrise Valiev Dr., Reston, VA 22091 Phone (703) 620-3950 For more (acts circle 15 on card. LAM 001315 that a worker is exposed to 10 fibres/ cc for 15 minutes he could be exposed to 1.7 fibres/cc for the rest of his shift, i.e. 5 x 10 465 x 1.7 = 480 x 2. Lemen et al" showed that more than 50% of the operations in textile operations were able to meet the 2 fibres/cc limit and control technology to meet the 2F/cc level existing in all operations in the friction product industry. A study has been carried out in Ontario to determine the technolog ical feasibility of the 2 f/cc standard21 as is the Beaudry Commission in Quebec.The Ontario report" shows 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 able 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 capable of working under the necessary constraints imposed upon them. Other Occupational Standards (1) The BOHS has recommended a level of 0.2 fibres/cc for crocidolitc.2" (2) The BOHS also gives the follow ing alternative indices for chrysotile asbesots.2" Respirable mass: -0.03 mg magnesium/m1 -0.04 mg SiOj/m5 -0.10 mg ash/m1 --0.12 mg asbestos/m1 Thermal Precipitator: 25 ppcc greater than 1 um after incin eration. Impinger: 10 ppcc Royco 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 tile asbestos and the equivalents may not be applicable in other places. The joint ACGIH--AIHA Aerosol Hazards Evaluation Committee2" 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 1971 the Environmental Protection Agency, U.S. Government proposed emission standards concerning the following: (1) Emissions shall not exceed those which would be emitted from operations if proper engi neering control had been in stalled (i.e. fabric filter, cyclone gas cleaning devices). (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 and 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 Laboratory, California State Department 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 be no visible emission or certain specified control equipment must be used, e.g. a baghouse, high energy scrubber, etc. Ontario has an emission guideline1 which is 5 micrograms per cubic metre averaged over a half hour at point of impingement. This guideline refers to NOVEMBER'DECEMBER. 1977 DPMC-17013 41 LAM 001316 the maximum concentration of asbes tos averaged over a half hour result ing from the plume from any source, stack or vent, impinging on any recep tor, a school, shopping centre, ground, etc., at the time when the wind is blowing from the source directly toward the receptor. Since wind direction is variable and since more than one source may impinge on a given receptor at one time, the emission guideline is devel oped to encompass these variables in such a way that, if every source meets the emission guideline, the ambient air quality guideline will not be exceeded. Thus, there is no direct numerical relationship between the emission guideline and the ambient air quality guideline. The ambient air quality guideline is the maximum concentration, averaged over 24 hours, to be found anywhere in the community. Table II summarizes some of the air quality standards in force today. The Final National Emission Stan dards for Hazardous Air PollutantsAsbestos and Mercury, promulgated by the U.S. Environmental Protection Agency, were published in the Federal Register of October 14, 1975" and are effective as of that date. Initially the standards appeared in the Register of Have confidence in your test results: accuhaler 808" the accurate personal sampling pump Accuhaler 808 Personal Sampling System (including pump, orifices, tube holder and calibration kit.) Precise total volume measurement Easily calibrated Sample for Benzene, Toluene. Petroleum Distillates, and other organic substances Controlled inhalation Will not operate when (tow is blocked Reproducible and verifiable results Low, adjustable flow rate. Vt cc to 96/cc/min. MESA approval no. 2G 3026 for Methane Atmospheres BASEEFA approval imminent and CERCHAR approval no 776S84X For use with Charcoal, Silica for Hydrogen Atmospheres Gel and Low Flow Detector Tubes For additional information and your free copy of the Charcoal Tube User Guide, call or write: MDK SCIENTIFIC, INC. SOOBusseH^hwoyPakfkRRidigdeg.e.ihotsiOObfl Ptxne;3I2 (W6-4250 telex 72-6399/VIDA-PPID >V1DNEuropean Subsidiary: 'l/ll I LX SCIENTIFIC (UKJLTD. FerndownkndEst 86CobhomRd Wimboine Dorset. BH217PG England Phone 202-872106 Telex 4)7 2290MSATP G April 6, 1973." The amendments thereto were proposed October 25, 1974. The following are some of the high lights of this new document as it concerns asbestos. (1) The "no visible emissions" clause for the waste disposal of asbestos materials remains in effect. (2) Asbestos mills are exempt from the requirement to wet tailings when disposal site tem peratures are below 15 F. (3) Only asphalt concrete manufacturing plants that use commercial asbestos are af fected. (4) Local exhaust ventilation systems may be used during certain renovation operations. (5) Containers of asbestos waste may display either an EPA or an OSHA warning label. (6) Clarification is given of the definitions for "planned renovation" and "emergency re novation" operations. (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, oh&s REFERENCES 1. Rajhans, G.S.: Fibrous Dust--Its Mea surement and Control, CIMM Bulle tin., pp. 900-910, August, 1970. 2. Dressen, W.C., Dallavalle, J.M. Ed wards, T.l. Miller, J.W. Sayers, R.R., Easom, H.F. and Trice, M.F., "A Study of Asbestosis in the Asbestos Textile Industry," Pub. Health Bull. No. 241, Washington, D.C., 1938. 3. Addingley, C.G.: Asbestos Dust and its Measurement, Ann. Occ. Hyg., 9, 2., 1966. 4. Committee of Hygiene Standards of the British Occupational Hygiene So ciety: Hygiene standards for chrysotile asbestos dust. Ann. Occup. Hyg. 11:47-69, 1968. 5. Leathart, G.I., and Sanderson, J.T., "Some Observations on Asbestosis." Ann. Occup. Hyg., 6: pp. 65-74, 1963. 6. "Threshold Limit Values of Airborne Contaminants," Adopted at the 30th Annual Meeting of the American Conference of Governmental Indus trial Hygienists, St. Louis, Missouri, May 13, 1968. 7. "Hygiene Standards for chrysotile asbestos dust," Ann. Occup. Hyg., Vol. 13, pp. 7-15, 1970. 8. Roach, S.A., "Hygiene Standards for Asbestos," Ann. Occup. Hyg., Vol. 13, pp. 7-15, 1970. For more facts circle 16 on card. 42 DPMC-17014 OCCUPATIONAL HEALTH AND SAFETY .rch 7, 1977 ' JB SAFETY&HEALTHrepor Page 37 EWKPROPOSES ADDITIONAL ASBESTOS RESTRICTIONS; CLARIFIES DISPOSAL REGULATIONS / The spraying of all materials containing more than 1% asbestos would be prohibited on buildings, structures, structural members, pipes and conduits under proposed Environ mental Protection Agency amendments to the Clean Air Act. Amendments, which appeared in the March 2 Federal Register, would extend current demolition and renovation pro visions of the Clean Air Act -- which cover spraying and removal of asbestos-containing materials used in fireproofing and insulation -- to include decorative coatings. Amendments were proposed in response to recent information EPA has received show ing that asbestos used in certain types of decorative spray-on materials contains 2964% asbestos. Because these materials may crumble easily, EPA says they could be a "major source of asbestos emissions during renovation and demolition operations." In other action, EPA also issued final amendments to the demolition and renovation provisions of the asbestos standard to make it clear that the 1975 regulations apply to both load-supporting and non-load supporting structural members such as beams, ceilings and walls. Comments on proposed amendments should be addressed to Emission Standards and Engineering Division, EPA, Research Triangle Park, North Carolina 27711, Attention: Mr. Don R. Goodwin, by May 2. *** AFL-CIO SEEKS FEDERAL STANDARDS FOR WORKERS' COMP; PROPER OSHA ENFORCEMENT AFL-CIO renewed Its recommendation that Congress establish Federal standards for state workers' compensation programs In order to provide adequate coverage for all workers, at its strategy session in Bal Harbour, Fla., late last month. Union also called upon President Carter to rescind Executive Order 11821, issued by President Ford, which requires Occupational Safety and Health Administration to prepare infla tionary impact statements before standards can be promulgated. This order "places a dollar value on the lives or workers and has blocked development of occupational health standards," union said. In addition, union urged Carter to require the Secre tary of Labor to enforce job safety and health guidelines for Federal employes to set an example for private employers. In a statement adopted by the AFL-CIO's Executive Council, union criticized workers' compensation system, stating that "many injured workers, their dependents and, in some cases, their survivors are forced to the courts for protection through third party suits for damages, because of inadequacies in state workers' compensation pro grams." Union said that adoption of Federal standards could eliminate many inadequacies in the present system and restore workers' compensation "as the exclusive remedy of injured workers... making uncertain and often inequitable alternate remedies unnecessary.' AFL-CIO also criticized the past two Administrations for failing to properly - -- administer OSHA and said it was encouraged by President Carter's statements of support for the law and his desire to have OSHA regulations clearly drafted;- In the Administra tion's most recent statement of support for OSHA, Labor Secretary Ray Marshall told United Auto Workers March 2 that "we believe in these laws [job safety and health act of 1970] and we're going to try to make them work. There have been people in the past who did not believe in them and therefore did not try to make them work. It's diffi cult to administer a law you don't really believe in," Marshall said. *** LAM 001317 DISABLING INJURIES IN COAL MINES CLIMB 15% in 1976, MESA REPORTSDisabling injuries occurring in the coal mine industry in 1976 climbed 15% above the 1975 rate of 31.07.per million man hours of exposure to 36.41 per million man hours, according to preliminary statistics released by the Mining Enforcement and Safety Administration. But the total number of fatalities -- 141 -- was -14 less than in 1975. Mine operators reported a total of 14,085 disabling work injuries during 1976 and.11,853 nondisabling injuries. One major disaster, the Scotia coal mine tragedy in.Kentucky, resulted in 23 deaths. Three other accidents involved double fatalities. Highest injury frequency rates occurred. In anthracite coal mines, where there was a rate of 132.04 injuries per million man hours. 701 Ft I March 7, 1977_ SAFETY & HEALTH REPORT. _____________ Page 38 FOUR MINERS KILLED, FIVE MISSING AS FLOOD WATERS OVERRUN MINE Four miners were killed, three seriously injured and five others are still miss ing as a result of an underground flood which surged through a tunnel of the Kocher Coal Co. mine, 40 miles northeast of Harrisburg, Pa., March 1. Another miner was rescued after spending 116 hours in a tiny coal mine cavity before he could be reached. But rescuers' attempts to pick up sounds from remaining miners in the shaft have been unsuccessful. Although the source of the flooding remains a mystery. Federal and state mining officials are speculating that water could have come from the runoff of .melting snow or from water accumulating in an abandoned mine nearby. Region is filled with aban doned anthracite tunnels, many-of which are unmapped. A full investigation into the causes of the flooding will be conducted by Mining Enforcement and Safety Administra tion when all the missing miners are accounted for., Kocher mine has been in operation since-.1968 and has had no fatalities prior to this. ,,** LAM 001318 AROUND THE STATES ........... CALIFORNIA-- Preliminary survey results of room air in private residential and public buildings in Los Angeles, the Bay Area and Fresno showed no counts of asbestos fibers in excess of existing job safety and health standards. State Health Director Jerome A. Lackner announced. But further sampling of building environments -- parti cularly in new office buildings which contain considerable amounts of asbestos-coated materials -- will be done to enable department to expand its data base, he said. CONNECTICUT -- An eight-member panel appointed by Gov. Ella Grasso to study state's three nuclear power installations has criticized Federal reactor safety studies for failure to adequately consider the latent effects of radiation, the possibility of sabotage and the malfunctioning of equipment, according to Dr. Gifford B. Pinchot, a physician and former biology professor who is a member of the panel. Panel will shortly recommend to the state legislature that it create an independently-funded state office on radiation safety. This office would have the responsibility for plant safety, quality assurance, radiation detection, worker health and safety, and trans- s portation of radioactive material. Panel will also recommend that studies be con ducted to minimize effect.of medical and dental X-rays upon technicians and patients .and that additional funding be allocated to study extent of radiation-related diseases ,,among nuclear plant employes and persons residing near plants.^ V ..-.GEORGIA -- National Center for Disease Control in Atlanta is trying to determine . the cause of the recent deaths'of two CPC employes who worked at a laboratory where dangerous viruses are studied, George Flowers, 49^ who delivered supplies to the ... laboratory and picked up used glassware that had been sterilized, died of intestinal .... bleeding that followed.high fever, chills, nausea, muscle aches and diarrhea/ Robert Dubingon, 43, who had.janitorial duties, died of kidney failure after experiencing the -same symptoms. A CDC spokesman told JS&HR that both men had very little contact with .: the viruses that are studied^in the laboratory and that both were required to be immu nized against the various viruses with which they might come in contact. ' Legionnaires disease and other more common'diseases.have.been ruled out. Latest speculation is that disease was caused by a rlckettsia'which can cause Rocky Mountain Spotted'fever and other diseases. Such diseases are not spread by human contact. VERMONT -- Vermont.has become the sixth state to receive certification from the Occupational Safety and Health Administration.that all the developmental'steps specified in. its state plan for job! safety..and health are complete. Vermont' will"receive 50% Federal funding for.program,operations through Sept. 30, 1977, amounting' to $285,666. . QSHA will continue to monitor and evaluate Vermont's plan for'at, least;one 'year'to determine whether the program, in operation, is' at least as effective as the national program. Final approval...of^ the. plan may be granted and Federal jurisdiction in the state.withdrawn at the end;of the period. ~ But OSHA' will, continue to monitor" and^eval-^ uate. the program to assure. tha It remains effective^' Certification' of1' the'plan;^' which was first apprpved in' 1973,. comes at a time5 when' a bill is pending in1* the' state legislature to abolish the state program (JS&HR, Feb. 7, 1977, p., 22). \ DPMC-17016 i le w M ie iu e i No. 11, September 1982 Clayton Environmental Consultants, Inc. LAM 001319 NEW DEVICE MEASURES ASBESTOS FIBER RELEASE By David Hands, C.I.H. Senior Industrial Hygienist Asbestos has long been recognized as a material which has excellent fireresistant properties, and for many years it was used in building construc tion where fire-retardant construction Cellosolve Exposure Limits Too High? Recent studies by the National Institute for Occupational Safety and Health (NIOSH) have indicated repro ductive effects in male and female test animals from exposure to several glycol ethers and their acetate derivatives. These results, and results of testing prompted by the NIOSH studies by private industry roups, have led the American onference of Governmental Indus trial Hygienists (ACGIH) to recom mend lowering the threshold limit values (TLVs) for 2-ethoxyethanol (Cellosolve solvent) and 2-ethoxyethylacetate (Cellosolve acetate) from 50 to 5 ppm. In addition, most manufacturers of these solvents have issued advisory letters to their customers suggesting that exposures be reduced to the greatest extent feasible until the exact nature of the risk is ascertained. These solvents are widely used by industry and are known under such trade names as Cellosolve, Dowanol EE, Methyl Cellosolve, and Dowanol EM. Use of these solvents and asso ciated worker exposures should be reassessed. This may include review ing the manufacturer's suggestions or monitoring Cellosolve exposures. For additional information on Cello solve, please contact the Clayton industrial hygiene department. was desired. Recently, of course, poten tial health hazards resulting from ex posure to airborne asbestos have been revealed. However, the mere presence of asbes tos containing material may not in itself present a hazard; concern arises when asbestos fibers are released into the air a$ a result of maintenance activities, vibration, or airflow (the space between the suspended ceiling and the above floor, where structural members and subflooring are coated with the fire proofing, often serves as a return air plenum for building ventilation sys tems). The integrity of the fireproofing, and its potential for fiber release, may be affected by aging, water damage, past renovation activities, and of course the original composition of the material when it was applied, especially the per centage of asbestos included in the composition. Because the materials were generally prepared onsite, con siderable variation in composition often exists even within a building. Several methods are used to deter mine whether a building containing asbestos-bearing fireproofing in fact poses a potential asbestos exposure problem to occupants and maintenance personnel or outside contractors. Air sampling in the office areas can be performed, but fiber concentrations are generally very low because the sus pended ceiling acts as a barrier to fibers. However, removal of ceiling panels for routine maintenance and inspection has been found to result in measurable fiber concentrations to employees performing the removal. Presumably office occupants would also receive exposure during this apparently innocuous procedure, so air sampling under normal conditions may not reveal an existing potential hazard. The only standardized method for testing friability, defined as the tendency for a solid material to frag ment when subjected to mechanical energy, is designed for coal and has application in material handling. A modified version of this ASTM (Ameri can Society for Testing and Materials) method was performed with asbestos at Clayton's laboratory, but results can not be related to potential occupant exposure because the bulk sample of fireproofing needed for the test must be removed from the building and because the result of the test is expressed as the percentages by weight of the origi nal test sample which fall into certain size categories after the tumbling period. Further, the tumbling does not (Continued on Page 2) Clayton Opens New Jersey Office Clayton Environmental Consultants, Inc. is pleased to announce the acquisi tion of Occupational Health Services, the industrial hygiene and laboratory service organization, formerly owned by American Can Company. Fully ac credited and licensed laboratory serv ices will now be available from two locations -- Southfield, Michigan (main office) and Edison, New Jersey. In addition, the New Jersey office brings the number of Clayton locations to five (other Clayton offices are located in Southfield, Michigan; Atlanta, Georgia; Houston, Texas; and Windsor, Ontario). Occupational Health Services has long been regarded as a forerunner in the field, and Clayton welcomes the addition of the OHS professionals to its staff. The new office and laboratory is located at Raritan Center, 160 Fieldcrest Avenue, Edison, New Jersey 08837. The manager of this office is Kirit Vora, who may be reached at (201) 225-6040. Other professionals include Allen Guy, Joseph Pedalino, William Harley, and Lee Schumann. DPMC-17017 New Device Measures Asbestos Fiber Release (Continued from Page 1) simulate the conditions which would be experienced by the material during maintenance or aging. Two methods exist for assessing some aspect of sprayed-on fireproofing in situ (i.e., as it exists in a building), the EPA algorithm and ASTM E736-80, Cohesion/Adhesion of Sprayed FireResistive Materials Applied to Struc tural Members. The EPA algorithm, used widely in schools, weights the condi tion, accessibility, friability, and asbestos content of the material in per cent to derive a number which is used to rank the material. However, the only objective element of the algorithm is asbestos percentage; the remainder of the elements are rather subjective and thus susceptible to being scored differ ently by different individuals. Finally, no relation between the algorithm re sults and actual fiber release has been demonstrated. The ASTM test consists of cementing a wide-mouth bottle cap to the fireproofing with a polyurethane foam and then pulling on a hook at tached to the cap while measuring the applied force with a spring scale. Al though this method is repeatable, it measures only the strength of the bond of the fireproofing to itself (cohesion) and to the structural member (adhesion). These properties may or may not corre late to the tendency of the material to release fibers when subjected to me chanical energy, such as being struck by a tool during maintenance of elec trical or heating equipment. To overcome the lack of a meaningful standardized method for assessing fiber release potential. Clayton has developed a device (see figure) which imparts mechanical energy to asbestos bearing fireproofing while air samples are being collected. Clayton is perform ing testing on a number of materials to develop an index of fiber release poten tial. Once the index is developed, it will be possible to compare a given material with others which have been subjected to the test procedure. The device employs a counterweighted lever to deliver the impact to the material. The impacting lever is con nected to and cocked by a cam connect ed to a gear motor. When a step in the cam is reached, the counterweighted end of the lever falls and the impacting end strikes the fireproofing material with repeatable impacts at the rate of 16 per minute. Three sampling filters are arranged slightly below the impact area to collect fibers released. The filters are located within a cylindrical shroud which protects the test area from air currents which often exist in the space between suspended ceilings and the sub-floor above. The device and the sampling pumps operate for 20 minutes at each location, and the fiber concen trations indicated by the three samples are averaged to determine the result for each test. Main Office 25711 Southfield Road Southfield, Michigan 48075 (313) 424-8860 Laboratories Edison, New Jersey Southfield, Michigan Clayton of Canada 400 Huron Church Road Windsor, Ontario N9C 2J9 (519) 255-9797 Editor Preliminary results have been very encouraging. To ensure that the method is indeed repeatable, duplicate sam pling has been conducted. That is, two tests have been performed with impact points 1 inch apart. The average fiber concentrations for the first test were compared to the average for the second test. These two averages have been reasonably consistent, indicating that the test procedure is repeatable. In a given building, fiber concentrations generated by the device have also been fairly consistent; occasionally, though, locations within a building were found to have considerably higher fiber releases. At this point a detailed statistical study of the results has not been con ducted, but sampling in progress now will provide sufficient data to develop an index of fiber release. This index will permit comparisons of the fiber release potential of fireproofing in different buildings. The characteristics of these materials may change over time, and this device can also be used to monitor the fiber release potential of a given fireproofing material over time. One further application of this test proce dure is the determination of the effec tiveness of encapsulation treatments. Editor's Note: Clayton has applied for a patent for this device. U.S. Branch Offices 2141 Kingston Court, S.E. Suite 116 Marietta, Georgia 30067 (404) 952-3064 Raritan Center 160 Fieldcrest Avenue Edison, New Jersey 08837 (201) 225-6040 LAM 001320 Deborah H. Montgomery Southfield Office DPMC-17018 Accidental Hazardous Chemical Spills -- Evaluating Their Community Impact By David R. Derenzo Air Pollution Meteorologist Over the past few years there has been an increase in the use, production, and transportation of a wide variety of chemicals. As a result, the chances of accidental spills and inadvertent re leases of these substances into the ambient environment have risen. There have been numerous cases where train tank cars have derailed and tank trucks have overturned, spilling their chemical cargos. Human exposure to these chemicals can result in adverse health effects. Therefore, in the event of a spill, it is important to be able to estimate the area of impact resulting from the formation and movement of a potentially hazard ous chemical cloud. Computer simulation models specifi cally developed for this purpose are utilized by Clayton. The models are based on complex mathematical algorithms that describe the manner in which a specific chemical is released from a container and dispersed in the atmosphere. In general, there are two types of spills -- continuous leaks that may persist for some time, and large, sudden releases. These types of spills most often occur from transport lines and/or storage/transportation tanks. Many of the chemicals used or pro duced in manufacturing processes are in the form of liquids, and gases, which are usually stored and transported in liquefied form. Therefore, heat and/or mass transfer mechanics, depending on the nature of the chemical spilled, must be utilized to calculate the rate at which the spilled chemical evaporates into the atmosphere when in the ambient environment. The evaporation rate is used as an emission rate in an air dis persion algorithm to estimate downwind chemical concentrations at specific times and locations. Individual onsite systems have been developed for facilities that utilize hazardous chemicals in order to provide real-time data on the movement and impact of a vapor cloud resulting from an actual spill. These systems utilize a microcomputer programmed with the model that continuously monitors at mospheric and wind conditions. When an accident occurs, the current weather and spill data are input to the model to determine the impact on the surrounding environment as the spilled material moves downwind. This information is used in a program to immediately notify community officials and businesses in the area to establish evacuation zones and take necessary precautions. Similar highly movable systems have been and are being developed for use by emergency response teams to evaluate spills from ruptured transportation tanks and other sources. To apply the model to a particular situation, data on the spill and dis persion conditions are required. For example, chemical name, spill size, rate at which the spilled substance flows out of its container, duration of a continuous leak, wind speed, and atmospheric sta bility are used as inputs to the model. The simulation computer program can be used and adapted to obtain data for a variety of uses. Hypothetical spill scenarios from chemical sources within a plant can be evaluated to determine if the resulting vapor cloud has the potential to be hazardous to anyone within or outside the facility's confines. This type of information is important to management in determining potential liabilities, appropriate insurance cover age, and plant expansion, and to acquire immediate surrounding property (if the opportunity arises) to establish or expand a "buffer" zone between the plant and the nearest residential areas. LAM 001321 PC/PLM Provides Qualitative Analysis of Asbestos Air Samples By Jeanne Bedrosian Chemical Technologist The current method for analyzing asbestos in air samples adopted by the Occupational Safety and Health Administration (OSHA) is by phasecontrast microscopy using the National Institute for Occupational Safety and Health (NIOSH) Method P&CAM 239. The method counts all fibers having a length-to-width ratio of 3:1 and being longer than 5 micrometers. Therefore, cellulose, fiberglass, cotton, and wool may be counted as well as asbestos. This is often a problem since high fiber counts do not always indicate high asbestos fiber concentrations. To overcome this drawback and to identify specifically asbestos fibers, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) has been used. With these methods, fibrous forms are classi fied by morphology and identification is confirmed by energy-dispersive X-ray spectroscopy and/or selected area electron diffraction. The disadvantages to these methods are the high costand length of time for analysis. However, polarized-light micro scopy (PLM), which has been used extensively for analysis of asbestos bulk samples, combined with phasecontrast microscopy, now appears to be very promising in the quali tative analysis of asbestos air samples. In switching from phase contrast to polarized light, there is some loss in fiber resolution, which results in a lower fiber count, so the method should be considered semi-qualitative at best. Presently, Clayton per forms the analysis only on filters which indicate total fiber counts reater than 0.1 fibers/cc when the C method is used. The analysis is also limited by the mounting solution currently speci fied by NIOSH. The difference in refractive indices between the mounting solution and asbestos does not allow the use of dispersion staining, which is commonly used in asbestos verification. Despite these shortcomings, the method is attractive because it is faster and less costly than other qualitative methods. In addition, the development of a more appropriate mounting solution should enhance the reliability and usefulness of this technique. DPMC-17019 Clayton News Briefs Staff News Clayton Environmental Consultants, Inc. is pleased to announce that Kenneth F. Cherry. P.E., C.I.H., has joined Clayton as Manager of Environmental Engineer ing Services (EES). The EES Department incorporates our waste management, air pollution, and engineering design groups. Mr. Cherry has extensive experience with the evaluation and design of pollution control systems with several major engineering firms and with the Ohio Environmental Protection Agency where he was pre viously employed. He has authored a number of articles on pollution control, is the author of a recent book on plating waste treatment (Ann Arbor Science), and has received five patents ranging from an air pollution control device to ergonomics. Mr. Cherry has degrees in both Chemical Engineering and Economics. Mr. Timothy W. Ferrel, an Industrial Hygiene Technologist with the Southfield office, has passed the core exam in in dustrial hygiene given by the American Board of Industrial Hygiene. The exam was given at the American Industrial Hygiene conference in June. A paper prepared by Mr. Paul V.Harvath, Environmental Chemist at the Southfield laboratory, will be presented at a poster session at the Seventh International Symposium on Polynuclear Aromatic Hydrocarbons October 26 through 28, 1982. His paper is entitled "Use of Repeating Chromatographic Profiles in the Quantitative Analysis of PAH in the Coal Conversion Environment." The symposium, which is sponsored by Battelle Columbus Laboratories, will be held in Columbus, Ohio. Publications The results of extensive Clayton re search into two timely environmental issues have recently been published. "Medical Management of Chemical Exposures in the Petroleum Industry," prepared by Clayton under contract to the American Petroleum Institute, is designed to assist the health specialist in considering and recognizing the role of various environmental stresses and hazards in worker health problems in the petroleum environment. "Evaluation of the Relationship between Formaldehyde Emissions from Particleboard Mobile Home Deck ing and Hardwood Plywood Wall Panel ing in Experimental Mobile Homes" was prepared by Clayton under contract to the U.S. Department of Housing and Urban Development subsequent to a 2-year study of formaldehyde in mobile homes. For further information on these two publications, contact the Southfield office. LAM 001322 Copyright 1982 by Clayton Environmental Consultants. Inc.. 25711 Southfield Road. Southfield. Michigan 48075. A Technical Service of Marsh & McLennan. DPMC-17020