Document 1gzRg3o3ZOxpq91Rgb60RbNQa

PLAINTIFF'S EXHIBIT 0 1 CA &3 Co & <3> p3 (a & Co k i l* > cCdO lam 030170 0122.2 5 - SM 32 IB... 9-571 IO FILE SHELL OIL COMPANY REFERENCE c&r PF C rwrr q J kW- 1976 BWD mill i JFB CWS WAR GAV FILE date NOVEMBER 18, 1976 from ENVIRONMENT, LABOR & LITIGATION DEPARTMENT HEAD OFFICE LEGAL subject ASBESTOS VARIANCE cc: K. M. Parker, J. W. Pittman R. E. Joyner, ynn F. Aurelius LAM 030171 ABS-012226 SM.32ffi*v. 9-57) SHELL OIL COMPANY ol-AS^ST-oSH REFERENCE to HEAD OFFICE - OCCUPATIONAL SAFETY AND HEALTH MANAGER DATE DECEMBER 22, 1976 from REGIONAL REPRESENTATIVE ENVIRONMENTAL & SAFETY ' SUBJECT CAL OSHA DEVELOPS NTS Local press reported Dr. David Parkinson, Chief Department of Health (DOH), OSH Section, was fired and is being replaced by James Heath, Los Angeles Health Department. As reported in previous memoranda, Parkinson's posture on OSH standards was rigid; socio economic should not be considered by the technical community in developing the standard. It is unknown whether Heath's view will be more balanced. The California Manufacturers Association (CMA) OSH Steering Committee met on December 9, 1976, to review the DOH Carcinogen Com mittee activities and consider a response to the DOH questionnaire referenced in our December 13, 1976, memorandum. This questionnaire sought to obtain information on "carcinogen" usage in California: to aid the State inspection program mandated in Senator Gregorio's S.B. 1678. Enclosed is a report prepared by the North American Asbestos Information Association. With their concurrence, it is being submitted to the DOH in partial response to the questionnaire. The report estimates there may be 100,000 - 135,000 workers in 80,000 work locations "that may be exposed at least occasionally to airborne asbestos fiber concentrations in excess of 1 fiber/cc time-weighted average". The Polyurethane Manufacturers Association is reviewing the MOCA usage; also Goodrich and Stauffer personnel have been alerted since VCM usage is covered in the questionnaire. It is unknown at this time what response if any may be offered by these groups.* Attachment * J..D. Joycr LAM 030172 l\leM $4r)Shutn " fh'pint' u@u> Cj ita*? h fat 0^ $kmd. &cai An Estimate of Occupational Exposure to Asbestos in the State of California / Submitted in Response to the California State Occupational Safety and Health Standards Board Proposal for Changes in Titles 8 and 24 of the California Administrative Code Relating to the Occupational Use of Asbestos 18 November 1976 LAM 030173 ABS-012228 TABLE OF CONTENTS Section ' INTRODUCTION METHODOLOGY AND ARRANGEMENT OF PRESENTATION ASBESTOS EXPOSURE - UNITED STATES Primary Industries Secondary Industries Consumer Industries ASBESTOS EXPOSURE - CALIFORNIA APPENDIX Tables from Roy H. Weston Report Page 1 2 3 3 7 13 15 s' 18-28 LAM 030174 ABS-012229 SUMMARY This report provides an estimate of the number of v/orkers in the State of California that may be exposed, at least occasionally, to airborne asbestos fiber concentrations in excess of 1 fiber/cc time-weighted average. The estimate is based on a report prepared for the Asbestos Information Association/florth America by an independent consultant. The Roy H. Weston Company, supplemented by published information on the Construction Industry. The California figures were obtained from the national data by ratio and are summarized in the following table: PRIMARY INDUSTRIES (Produce or use raw asbestos fiber.) SECONDARY INDUSTRIES (Use asbestos-containing products manufactured by primary industries.) TOTALS (Rounded) WORKER AGE DISTRIBUTION Over 40 Years of Age Over 45 Years of Age Work Locations 16 Except Construction 19.840 Construction 60,000 79.840 80,000 Exposed Workers 2,014 91,200 8.000- 40.000 99,200-131,200 100,000-135,000 43.000- 58,000 34.000- 46,000 1. At least occasional exposure to above 1 fiber/cc.TWA. The information presented for the Primary Industries is based on a comprehensive, in-depth survey which included a substantial amount of expo sure data.. It tended to rely mainly on responses from the larger manufac turers and probably understates both the number of employees and the number of locations. The Secondary Industries are much more diverse and the information shown had to be estimated from a variety of published sources supplemented by limited survey input. There was a reasonable amount of data on, the range of exposures that could occur but very little to define where and how after these levels actually happen in industry. It is important to recognize, therefore, the "... may be exposed, at least occasionally..." qualification that applies to the tabulated figures. These estimates are provided in good faith as the best information available today to assist the state of California in arriving at a reasonable and realistic occupational asbestos standard. We will be glad to provide more detailed information on the Construction Industry when it becomes available in the first quarter of 1977. LAM 030175 ABS-012230 1- - INTRODUCTION The California State Occupational Safety and Health Standards Board is now considering a number of proposed changes in Title 8 of the California Administrative Code covering the occupational use of asbestos and asbestoscontaining products. The impact of any changes made will obviously be a direct function of: 1. The number of workers affected. 2. The corresponding levels of exposure. 3. The number of work places affected. It seemed apparent at the public hearings on this matter held in Los Angeles on October 28, 1976, that the Standards Board had very little factual information available on these three important items. Thi%. presen tation is intended to provide the relevent data in this area that have been obtained by the Asbestos Information Association/North America (hereinafter the AIA) in connection with the preparation of a response to the current Federal rulemaking on asbestos. The AIA commissioned an independent contractor, the Roy F. Weston Company, to prepare an in-depth study of the asbestos industry and to assess the technical feasibility and economic impact of changes in the regulations proposed by the Federal government. This study was completed on March 29, 1976, and was on a national basis. It did not include the construction industry which was specifically exempted from the proposed changes. Two studies of the construction industry are now in progress, one by Research Triangle Institute under contract to OSHA and one by Equitable Environmental Health Associates, Inc., who have been engaged by the AIA. Only limited results are available from the latter work since completion is not scheduled until the first quarter of 1977. The time available does not permit a similar in-depth study of the asbestos industry in the State of California. As an alternative, the pertinent information on the number of workers, number of locations and range of exposure levels has been abstracted on a national basis from the Weston Report. The information available on the Construction Industry, which unfortunately uses approximately 70% of all of the asbestos products manufac tured, is not nearly as complete. The number of workers and a rough approx imation of the number of work locations have been estimated from the 1972 Census of Construction figures. These have been supplemented by some general observations on exposure levels based on quite limited published data. Finally, the corresponding numbers for the State of California will be estimated from national figures for the United States data by ratio, i.e. the number of manufacturing workers in California divided by the total number of manufacturing workers in the United States. LAM 030176 ABS-012231 2- - This approach is equivalent to the assumption that the distribution of the types of plants using asbestos in California is the same as the national average. While this is obviously not rigorously correct for all segments of the industry, California is a large state with a wide diversity of industry that employs nearly 10% of the work force in the United States. It is our judgement that deviations in detail will average out sufficiently to give a reasonably accurate overall picture. It is, in reality, the overall picture that is most important in assessing the broad impact of various regulatory alternatives. METHODOLOGY AND ARRANGEMENT OF PRESENTATION In order.to facilitate the study of the very complex asbestos indus try and to provide a workable format to present results, the Weston Company divided the industry into three segments in the manner described below: "Industry Structure Asbestos is a widely used inorganic fiber whose properties make it particularly well suited to many applications re quiring strength, chemical inertness, mold and mildew re sistance, and non-flammability. Many asbestos products pass through several manufacturing and fabrication steps before they reach the consumer. It is logical to expect different exposure levels and control tech nologies at different steps in the manufacture of any particu lar product; Weston, therefore, classified the asbestos pro ducts Industry into three groups: Primary Industries: those industries that start the manufacturing process with raw asbestos fiber and modify the fiber to produce an intermediate product (to be further processed or fabricated) or a finished product. Secondary Industries: those industries that continue the manufacturing process with an intermediate asbestos product (one in which the fiber has previously been modi fied in a primary industry), and further process, modify, or fabricate it to produce either another intermediate product (to be further processed or fabricated) or a finished product. Consumer Industries: those industries that purchase a finished asbestos-containing product (from a primary or secondary industry), and apply, install, erect, or co ure the asbestos-containing product without further physical modification of the product."(1) LAM 030177 1. Technical 'Feasibility and Economic Impact of OSHA Proposed Revision to the Asbestos Standard. Roy F. Weston, Environmental Consultants - Designers 29 March 1976. ______ ABS-012232 -3- The data for the United States has been assembled for each of these three categories and a summary table is provided for each category. The more detailed tabular data from the Weston Report which serves as the basis for these summaries has been assembled for reference in an Appendix section. The summary tables serve as the basis for the estimation of the corresponding employment and exposure figures for the State of California. ASBESTOS EXPOSURE - UNITED STATES - Primary Industries An overall summary of the quantities of asbestos used and the number of manufacturing locations for the various segments of the primary asbestos in dustry in the United States is shown in Table 2-1 (see appendix).(2) The figures are based on detailed information supplied by 58% of the industry and account for a usage of about 900,000 tons at 108 manufacturing locations. ^The miscel laneous category includes, among other things, the manufacture of tape-joint compounds, the distribution of raw asbestos to smaller users, and the use of asbestos in the drilling of oil wells. For the primary industries a two-part approach was used to assess employee exposure. The number of manufacturing workers in each industry seg ment together with the frequency of entry or time spent in the work area was determined. A detailed study of the range of exposure for each process step in each industry segment was also carried out. The combination of these two sets of results provides a reasonable estimate of the'number of employees involved and the approximate range of potential exposure levels. The type of worker exposure was divided by Weston- into four groups based on frequency in the work environment as shown below: ft The categories of exposure are defined as follows: 1. Continually in Work Environment: those whose normal work station is at a location involving asbestos exposure (production employees). 2. Frequently in Work Environment: those who enter an area of asbestos exposure on a daily basis, but who are not continuously assigned to such a location (maintenance personnel, foremen, supervisors). 3. Occasionally in Work Environment: those exposed to asbestos fiber, but who enter the work area on a less than daily basis (engineers, plant management, specialty maintenance personnel). Never or Very Infrequently in the Work Environment: those employed at the plant, but not in a production area (secretaries, clerks, guards)." (3) LAM 030178 2. Ibid. Page 2-11 3. Ibid. Page 3-5 ABS-012233 * 4- " Employment and exposure levels are presented in Table 3-1. The numbers of employees surveyed were taken directly from the questionnaires, and projected employment levels were based on the segment coverage figures in Table 2-1. Total projected employment in the primary asbestos industries is estimated to be 37,500, which is approximately 0.2 percent of the overall manufacturing work force. Very likely, this estimate is low, because in this survey a higher proportional response was received from larger plants. Small plants tend~ to be more labor-intensive; larger plants are likely to be more capital-intensive and more efficient. Projected figures, therefore, were based on large facilities and may tend to underestimate total industry employment. (Emphasis added.) Also, 37,500 represents employment at the plant level, and does (not) generally include corporate staff such as management, administrative, research, engineering, and sales personnel. The Miscellaneous segment was^omitted, because it tended to misrepresent true exposure levels in those plants handling the bulk of asbestos tonnage. Employees in the Miscellaneous segment do not make asbestos products similar to other Primary Industry segments; but. generally use small quantities of asbestos fiber to make an end-product more typical of secondary industries. In most of these plants, a relatively small number of employees handle as bestos; for example, in one plant only 5 of 1,140 employees handle asbestos. Including such a plant in Table 3~1 would tend to Indicate a generally lower level of exposure than actually occurs." (4) " Data provided by industry indicated 66.0 percent of plant personnel exposed on a regular basis (Categories l, 2, 3), or 24,750 employees. it is our opinion that this estimate is low; it is unlikely that 34.0 percent of employees at the plant level do not enter the work area on a regular basis. We believe that many responding to the questionnaire equated the four categories of exposure with levels of exposure (i.e., TWA fiber count), and, indeed several respondents indicated such. The proposed standard affects all those who are exposed to any levels, even if on an intermittent or non-routine basis. For instance, a clerk may spend virtually all his time in an office, except for fifteen minutes on Friday afternoons, when he delivers the payroll. This employee falls into Category 3, and is affected by certain parts of the proposed standard." (5) 4. Ibid. Pages 3-2, 3-4. 5. Ibid. Page 3-5. LAM 030179 ABS-012234 -5- Regardless of these reservations by Weston that both the total number and the percentage of workers exposed figures are too low, the sum of categories 1, 2 and 3 will be used as the basis for the California estimates. The other part of the picture, i.e. the levels of asbestos to which these workers may be exposed in the various primary industries are shown in detail by process step in Weston Tables 4-1 through 4-9 (see appendix).(6) Weston's comments on these tables follows: Ranges and Typical Data Value Statements The data reported to Weston on the industry questionnaires, as well as the data from plant visits and telephone contacts, were in the form of ranges of exposure levels or in the form of a single value that represented multiple data points. All data were assumed to be representative of employee exposures under normal production conditions for the processing steps involved. In several instances, however, the data range was'' extremely broad, indicating questionable sampling or counting procedures, or the inclusion of data collected during the non-routine operations. When such data anomalies were evident, Weston discarded those few anomalous data which appeared questionable. The resultant values are indicated for the segment and for each process step as: "range of fiber count with existing control technology, fibers/cc". The range of fiber count with existing control technology is further simplified by condensing the range into a single or "typical" value for each processing step. Where sufficient data exist, the typical value is approximated by the average of data points. In some instances, available data were insufficient for calculation of a meaningful average; in such a case, Weston selected a value which, in our judgement, would represent the "typical" value. The resultant values are in dicated for the segment and for each process step as: "typical fiber count with existing control technology, fibers/cc"." (7) The overall results for the primary industries needed for the present analysis have been collected in Table A, immediately following. For each industry segment the tons of asbestos used and the number of com pany locations (Table 2-1), the number of exposed employees (Table 3-1), and the range of TWA levels (Tables 4-1 through 4-9) are shown. The exposure levels are for the overall range for all process steps for each industry segment. This table serves as the basis for the estimation of the primary industries in California. 6. Ibid. Pages 4-11 4-23, 4-34, 4-42, 4-50, 4-58, 4-68, 4-76, 4-86. 7. Ibid. Page 3-6 LAM 030180 ABS-012235 b 9S32T0-S9V U8UOCO IAIV1 O <uJ CO Csj CM o XC>J CCT u CL, VS at .O CO o CM CM m o ro ro o r-* GO CO CO o CO oi. CO o LO o o csj CO CSJ o in co o o-- 30J 4--A3 OH1 o-J f--nj h-- E cf) cOnS CO *o4* CO to CO,oQX- LkJjUJ SkjOzr to< is:-,;wuoj>UJ oCOo|>* CUCCHOOOJ-.MUOZJ. < ioCfLceOo PO C C(U Hw 3CT EC 3>,0u 0w O 4- T~ f-- c > a.*-- c UEJ > tu S- O' 40- >3 **C" &- S- L. 01 o o I.3 33 C 0) VCOO in c or -- V) Co. u > > Xa> *--o LcU E3 ECL a os 5 O i- O' ro in CSJ o CSJ CO CO r-- CO CM O' o * mOs co o Os CO ro o r-- U*> in CO 00 CO IT) CCOOOS Csj Os CO CO co r-- ro-s* ocCMos CO r-- o rs* fs. o CO CO CM CM -3 --*ih V-o >L ,4Cr-O> t3>. C3O --CLOUO>1 o --^ 3 E oo H-- O 8 O oc o o in o in co CO CM o o o o o oo o o o o oo in o o o o r** co co CM r- #-- 3 -- CroT 4/0 3 PO> 4> VS O3 H X4>0 < 3 F 3 m > s. 4J VS 3 *o c in in in o CO CM to N ID CO o in CM ^ CO OS fc. Q. 41 a. Q. I/S v* a. o 4J O 4J Li VS VS c 01 3 (U .o X> vs VS 0J < <u in I o c *1- p 3 c vs a vs vs 4) Q JC 4^ 4/> o c 40 0> vs 0 to VS Q. vs vs h- O *M * 04- o i- u VS c c P vs os O o a> P c 4- TO P r-- u 4- 3 Pf 4J vs C 41 **- vs at VS *- o o -o c +* o> 01 J* ^ 0) u OJ 4-* o 1- o P-- IO a X) vs u X 4. JO X L 4- ro O V vs o> to 40 VS O in os u. u. a. 0.0 40 <u o a. < 'S- < H- rO vs *o o> c 3 -C L> L. 40 3 C o E o to o 3 OJ 4- o o u o *3 i/s o cc E *" oo uc CO 4/S 01 -*-> o e x: 3 .o o VE e o> 0) CM CO CO Ii//>I US ' 41 41 OS 3 ITS O Ai XXX O U x 40 ro <0 W O U Q.C n X3 S Q. OL OU pL iEg L> jO; b.U.UOQ U -- cm co ^ in co -7- Secondary Industries The secondary industries encompass those applications that continue the manufacturing process with an intermediate asbestos product and further process, modify, or fabricate it to produce either another intermediate pro duct or a finished product. These industries proved to be very diverse and difficult to characterize with a comprehensive set of statistics. Weston found it necessary to combine data collected from a variety of industry and trade associations, the Census of Manufactures, other government publications, and Dun and Bradstreet with their professional experience to estimate the numbers of employees and workplaces involved. The overall approach shown below was used: 1. The tonnages of the various categories of product, i.e. asbestos paper, floor tile, etc., that were used or further processed by the secondary industries were estimated. In some cases these tonnages were less than the total manufactured by the primary industries because some portion of the products are >jsed directly . by the consumer industries. 2. The number of employees in the secondary industries that handle asbestos products was estimated as 240,000 in production and maintenance and 60,000 in administration and management for a total of 300,000. This did not include employees in the brake installation and repair industry which were considered separately and the construction industry which was not covered at all. 3. The 300,000 employees were allocated to the respective product categories in proportion to the amount (tonnage) of asbestos contained in the products in that category used by the secondary industries. 4. The number of establishments was estimated on the assumption of an average of 25 employees per establishment to yield a total of 300,000/25 or 12,000 establishments. These were not allocated by industry segment. 5. Comprehensive employment data for the brake repair industry was obtained from information supplied by the Automotive Parts Rebuilders Association, the 1973 Service Job Analysis Report (Hunter Publishing Co.) and numerous corporations involved with brake repair shops. These data are summarized in Table 5-2(8). The fiber count data for the products covered are described by the following excerpt from the Weston report: 8. Ibid. Page 5-11. LAWI 0301828 ABS-012237 -8- 11 Fiber Counts The variety of processing and control techniques employed by the secondary industries and of the raw materials arising from all of the primary industry segments makes the definition of a general range of asbestos exposures meaningless. The data which Weston has acquired indicate a categorization of the secondary industries by raw materials received from the primary industry suppliers. The secondary industries are segmented according to the categories presented for the asbestos primary industries: asbestos paper; asbestos cement pipe; floor tile; friction products; paints, coating and sealants; asbestos cement sheet; gaskets and packing; asbestos-reinforced plastics; and asbestos textiles. Table 5"1 illustrates general ranges of fiber counts in these industries. Asbestos paper products are used to produce gasket materials, thermal and electrical insulation, roofing products, etc. Secondary segment products are charac terized by slitting, sawing, punching, pressing, con verting, and laminating operations. The range of fiber exposure is 1.0 to 3.5 fibers/cc TWA. oAsbestos cement pipe is manufactured and machined in the primary industries almost exclusively. The next step for this product is the construction (or plant maintenance) industry for installation. This segment's products, when 'used by the construction industry, are not subject to OSHA's proposed standard. Floor tile Is manufactured, cut, and packaged for shipment by the primary industries. The next step for this product Is either the construction industry (including builders and remodelers), or homeowners use for installation. There fore, this segment's products (when used by the construction industry or homeowners) are not subject to OSHA's proposed standard. Paints, coatings, and sealants are similar to asbestos cement pipe and floor tile; that is, they are used by the construction industry and home remodeling markets. Thus, this segment's products, when used by the construction in dustry or homeowners, are not subject to OSHA's proposed standard. LAW 030183 ABS-012238 -9- Friction products are used to manufacture brake and trans mission assemblies for the automotive, truck, heavy machinery, and railroad industries. A wide variety of motion-controlling applications are dependent upon in dustrial friction components. These secondaries receive the friction products from the primaries and form them into a product which requires drilling, sawing, tapping, grinding, and cutting of the friction products to conform to the product specifications. The range of fiber exposure is 2.5 to 6.5 fibers/cc TWA. Asbestos cement sheets are used widely by the secondary industries for molten metal and glass supports and troughs, thermal insulation, building materials, etc. A.R operations require some machining -- punching, pressing, sawing, drilling, sanding, etc. -- which generates substantial amounts of asbestos-laden dust. The range of fiber ex- . posures Is 1.0 to 6.0 fibers/cc TVA. Gaskets and packings are used as fluid seals in a variety of devices. They may be impregnated with polymers, latex, and other materials to yield special properties. Gaskets and packings which have been treated with chemicals to further bind the asbestos fibers release less dust than unbound materials when undergoing additional processes such as pressing, punching, and slitting. For gaskets and packings which are received from a primary industry with out a binder or as a yarn for making packings in the secondary segment, the range of fiber exposure is 1.0 5.0 fibers/cc TWA. Similarly, for those products which had been combined with a binder or impregnated in the primary industry, the range of fiber exposure is 0.2 to 1.5 fibers/cc TWA. Asbestos-reinforced plastics are used to make electrical switchboards and a wide variety of molded plastic products requiring a high strength-to-weight ratio. Secondary in dustries cut, drill, mill, and grind these materials ac cording to product needs. The range of asbestos exposure is 0.5 to 2.0 fibers/cc TWA. Asbestos textiles are processed into packing materials, friction products. Insulation, and protective clothing by the secondary industries. The textile product as received by the secondary may be bound with a resin which supresses dust evolution in the secondary processing; how ever, a portion of textile material is received as raw fabric. The secondary industries employ processes such as cutting, stamping, slitting, sawing, braiding, laminating, and sewing according to the specifications of the product. The range of asbestos exposure is 0.5 to 5.0 fibers/cc TWA.''(9) LAM 030184 ABS-012239 -10- The foregoing information on the Secondary Industries has been summarized in Table B. This table includes the tonnages of the various cat egories of asbestos-containing products processed by these industries, the estimated employment (production and total), the estimated total number of employment locations, and the range of TWA fiber levels reported. All of these figures come directly from the Weston Report except the exposure levels in the brake installation and repair industry. The Weston figures for fric tion materials apply mainly to manufacturing locations where the operations are carried out continuously. In repair shops the operations are intermittent, so TWA values should be considerably lower and are estimated to fall in the _raoge shown. The lower end of the range represents the fairly rare shop where good controls and industrial hygiene practices are in effect while the higher end is more representative of present typical job shop conditions. It is important to point out that Table B does not include the Construction Industry. This is a critical ingredient in the analysis of oc cupational asbestos exposure since this industry is the final consumer of about 70% of the asbestos-containing products manufactured in this country. In reality, it is difficult to find a job site of any appreciable size"that is not likely to contain asbestos in some shape or form. The number of v/orkers with potential exposure to asbestos may thus be nearly as large as the total of the construction workers shown in the following table from the 1972 Census of Construction Industries published by the United States Department of Commerce I I '$ No. of Establishments Construction Industries (Total) 430,027 Special Trade Contractors (Only) 268,982 Construction Workers 3,464,203 1,817,126 All Employee 4,083,465 2,106,599 Although the definitive studies of this industry will not be available for several months, it seems important that the California Standards Board be aware of the size and nature of this industry and at least of the order of mag nitude of the compliance problems it may present. A brief description of the AIA's best estimate of the current exposure situation in this industry is, there fore, provided here. Much of the present awareness of asbestos health hazards originated from the use of dry asbestos mixed with water as sprayed building insulation and from formed asbestos shapes used to insulate pipes and equipment. These practices have been discontinued for some years. While the insulation already installed is a concern for certain demolition and repair operations, these products are not now a source of exposure for the great majority of the con struction workers. Today the asbestos that is delivered to the construction site is generally either bound or encapsulated or, if dry, has been diluted to a very low level by other ingredients in the product. The rate of fiber release from such products during use will depend upon the amount of asbestos in the product, the nature of the binder, and the amount of energy imparted to the product to break fibers loose. The resulting airborne concentration in the work area will depend on the duration of the operation, the volume and the ventilation of the area into which the fiber is released. Each product used can thus give a LAM 030185 ABS-012240 IVZZTOSSV 981<00 IAIV1 4CL->.l r4(-A1 a O > ID eQ4c1. --4,, 1I A u uu V- 41 S. O X) IA *- L. 41 Li. 41 CH X) cICcC<t--2U**". CO Cl rjQ-- Z to <0 Oo o. o. crv ID O VD CM I* in ^ CM O oo o CO m CM Q. #-- CM in d *o o <D h- 44-0* 4*-3> O T- O o co V CM o o o o oo in o o o o o oo o ion oo O ion ion O * 11 * * 11 CO c- o * 0> co r** cr> CM o r. CM o o o oo VO o oooo o o o o 3" o o O o r- o CVJ o o *3- V) 41 "O X> 41 IA <A < r> viOo co o in m in 00 CO cm co o o o **- *o O 41 *-- VI 3 41 3 -O C (A, CD CD CM CO o in VI O 4- X(4A> *401 (A (A C=> O CO CO o in VO CM c4Jr CO O*- X431 V* IVDI c 4-> O oo o O oo om oin 3 -4O1 C VI 5** V> >1 *L. 41 4-> ^ V) 4. 3O o 3r C v> CM t- aic o o o o oo o ooo co o in o CO r> *a- CM *-- - rm o >> *- o 1- *J 40 VI o E 3O * X3 CO LC d**- 4 JZ C >>4-> 1- L 40 01 X3 XJ 4- VI c 41 c >> O a>. c ns a. in o o o m o o c O CJ r- O O IO fll -- 4-1 VI *-- C 40 o > o x> o 4- E 41 ,-- 40 4-> o 4-1 ( r-N. VO CO CM r- o vi *0 o O Cl *o V- l r~ 4^ VI 41 o> VI VI VI 4i ai 3 4-> < Xu c: vi O 41 01 <g l l Ul -- d 4i 1 v- 5 41 V4-) .<. CM O 41 c d4 L vi Cl 41 v> to Cl : -- C O CO x XcI vO -yC v<o ve* 3s o o o o ooo o o o o ooo 4- --_C Oc > r0-1 in oo o mo o C O J O U 4- . f-. *3- r- vO m cs o V. *-> <e fl o o Q3. W01 (WA CCl. V3* X 0* <o u *0 X c T3 E D O C O c 41 *" *3 in *" W. -- (A V O 41 CXV ig ia L >> do CO UJ CLh- X> c X XM^C(3>CA3i+<cE&44>/11) 0u1 CL oto. <J4oVVV43-1*)II Q41. 4oV-I X<i4vA1Ii CL o4C4E4-1i 41 ooc IL -4OU<cr--uU. o4Ovu31-O.). 9 VI +-> tz aA3 *OVVOOcr-Il rC4Vi<4caO-10lI V4v41>> <J4oVV4VO11tIII JmZ on4Ec411 TC*3o J4m#V4C-o1I *mCraUid c# 41 4uV*1-I CC to Xio4vV*n-1iI a. *uuO4o1 VOI X4Vt4n-1*I --V41I PX41 VO4<3C1oI r-- rm4U*-) to ofc---- -12- wide range of airborne asbestos concentrations depending on where and how it is used. Different products, however, may give quite different concentration ranges. The levels of exposure that can occur in construction can be illus trated in terms of the various types of products involved. The installation of asbestos-cement sheet when extensive cutting is required probably represents the high end of the range. Values from several fibers per cc to thirty or more fibers per cc have been reported. The sanding of tape-joint compounds, mixing of spray stucco, and the cutting and grinding of reinforced plastics falls in _an intermediate range. These operations tend to occur for limited time periods. Although there is some disagreement regarding exposure levels, partially because there are difficult samples to count accurately, TWA values of several tenths of a fiber/cc up to perhaps 3-5 fibers/cc appear to be representative of normal commercial operations. On the low end of the range are products like vinyl asbestos tile, roll flooring, roofing paper, paints, caulks and sealants. With these materials it is generally difficult to demonstrate exposure levels that are significantly different from background. The asbestos concentrations just described refer to the source, i.e. the immediate vicinity of the operation generating the dust. There will be a decreasing gradation in exposure as the distance from the source increases. Exposure will also be less on days when asbestos is not being used. Quali tatively four "classes" of exposure can be identified. 1. Workers who regularly install asbestos-containing products. There will be almost daily exposure to these workers at different parts of the same construction site or on different sites. 2. Workers who do not themselves use asbestos but who happen to be scheduled to work in the immediate vicinity of the instal lation of asbestos products during the time they are being installed. This exposure level will be similar to that of the workers using the asbestos but will generally occur for a con siderably lesser number of days per year. 3. Workers who pass through the area occasionally while asbestoscontaining materials are being used. 4. Workers who are on the site while asbestos is handled but are at distant locations, those who are on the site on other days, or who subsequently pass occasionally through an area where asbestos has been used. This rather orderly progression is complicated by the fact that more than one asbestos-containing product is often used on the same site and that, during clean-up, short but possibly fairly high exposures can occur to whoever happens to be in the vicinity. The difficulty in accurately characterizing exposure in the construction industry is obvious. The numbers of construction workers potentially exposed that was given previously can, however, be combined with the approximate exposure levels and exposure patterns just described to make a rough estimate of the exposure situation in the construction industry. If the criteria of "exposure" is defined as exposure to even a single fiber as would be LAM 030187 ABS-012242 -13- the case for a strict interpretation of the present federal regulations, vir tually all of the 3,464,203 construction workers would be covered and would need at least an annual physical examination. It does not alter the situation particularly to change the interpretation to include only exposures that are above the background level because the analytical procedures are very inaccurate at such low levels. The distinction cannot be made with any degree of reliability Changing the criterion to cover only an exposure of a 1 fiber/cc TWA for even a single day out of the year would obviously make a sharp reduction in the number involved. A range of 500,000-2,000,000 workers is estimated for this definition of exposure. A further change to a requirement of regular " exposure to a 1 fiber/cc TWA would tend to limit the coverage to the portion of the Special Trade Contractors who work with the asbestos-containing materials plus employees of other contractors who are regularly assigned to work in the same areas. A range of 100,000 to 500,000 workers is estimated to be covered by this much more limited criterion. The number of work locations is also obviously large and difficult to determine accurately. The Census reference cited defines a "construction establishment" as "...a relatively permanent office or place of business at which or from which the usual business activities related to construction are conducted". Mote that it is the business office not the construction site. If each establishment did business on only two jobs per year almost 900,000 job sites would result. There are over a million housing starts annually most of which use some kind of asbestos containing product. The figure of a million and a quarter working locations covered to some extent by the asbestos regu lations seems a reasonable and conservative estimate. For more the restricted exposure criteria of "occasionally above 1 fiber/cc TWA" the number of locations would not drop appreciably since housing sites tend to contain some asbestos and represent a'major portion of the work location. Significant exposures can result during clean up here. A figure of 1,000,000 locations is thus estimated for this approximate expo sure level. The same situation is largely true for ^'regular exposure above 1 fiber/cc TWA". Although the number of exposed workers is down considerably the special crafts concerned work at a substantial number of sites each year. Accordingly, a figure of 750,000 sites has been estimated here. The estimates just described have been summarized in Table C. Consumer Industries The "Consumer Industries" were defined previously as those industries that purchase a finished asbestos-containing product, and apply, install, erect or consume the asbestos-containing product without further physical modifica tion of the product. Under this definition exposure levels would generally be down in the range that would be difficult to distinguish from background. As might be expected, detailed characterization of these industries was very dif ficult and Weston relied mainly on the National Input/Output Table and the Census of Manufactures to arrive at the following estimate of workers and loca tions continuously involved with asbestos-containing products:O0) Employees 11,800,000 Establishments 140,000 LAM 030188 10. Ibid. Page ABS-012243 -14- TABLE C PRELIMINARY ESTIMATE-ASBESTOS EXPOSURE IN THE CONSTRUCTION INDUSTRY IN THE UNITED STATES Approximate Exposure Level Any exposure to a ------- single fiber, or Any exposure above background. ------- Occasionally above 1 fiber/cc TWA Regularly above 1 fiber/cc TWA Number of Workers 3,500,000+ 500,0002,000,000 100,000500,000 Number of Work Sites 1,250,000 1,000,000 s' 750,000 LAM 030189 ABS-012244 -15- ASBESTOS EXPOSURE - CALIFORNIA The information in Tables A, B, and C has been used to estimate the corresponding exposures for the State of California. This estimate requires two adjustments from the national figures: 1. A ratio for the number of workers in California compared to the total number of workers in the United States. 2. An estimate of the proportion of the workers in the U.S. totals shown where exposure exceeds a time-weighted average of 1 fiber/cc >5p. The ratio needed was obtained from the data on manufacturing employment in the 1972 Census of Manufactures shown below. For simplicity a value of 0.08 was selected. This number is in accord with the "10% of the U.S." figure commonly quoted for California. All Employees Production Workers California United States Rati Wi1 1,546,000 19,029,000 0.081 Use 0.08 1,020,000 13,529,000 0.075 At their meeting on October 28, 1976, the California Standards Board adopted-a 1 fiber/cc >5y TWA cut-off level for monitoring and medical examin ations. Mo requirement that such exposure should occur for any minimum number of days per year was included so a worker who is exposed to this level for even a single day would be covered. Examination of Tables A and B indicates that the 1 fiber/cc TWA level could be exceeded in the work area at least occasionally for all of the industries considered. Accordingly, the categories "Number of Workers in Working Envir onment" from Table A and "Production" employees from Table B have been used as the basis for the California calculations. These categories cover a substantially lower number of workers than the totals in the respective industries and their use is intended to provide a conservative estimate. Since a place of employment must be counted regardless of the number of workers exposed, the total U.S. figures have been used as the calculation basis. For the Construction Industry, Table C, the exposure levels are less well defined. In view of this uncertainty and in an attempt to avoid over estimating the figures for "Regularly above 1 fiber/cc TWA" will be used as the basis for the California estimate. The relevant U.S. figures and the corresponding values for California calculated via the 0.08 factor are summarized in Table D. In the Primary In dustry group, the U.S. numbers did not include the manufacture of tape joint compounds or the mining and milling of asbestos. California is unique in that it has three asbestos production operations. Approximately five tape joint compound manufacturers in the state use asbestos. Some figures to include these have been added. Weston noted in their report that the survey method LAM 030190 ABS-012245 -16- tended to miss the smaller primary industry operations. It is suspected that' the actual number of primary industry locations in the State of California is several times larger than the 16 estimated. Table D shows quite clearly, however, that the exposures in the primary industries are heavily outweighed by those in the secondary industries, particularly those for brake repairs and construction. Obviously, these num bers could shift widely depending on a better definition of actual exposure levels but they do represent the best estimate that can be supplied at this time. It should also be noted the number of locations for construction exceeds the number of workers exposed because it is characteristic of this industry that a worker is employed at a multiplicity of locations each year. It should be noted that Table D does not include the Consumer Industry category since exposures here are generally expected to be well below 1 fiber/cc. It is relevant to point out, however, that the Standards Board will be required to promulgate reporting requirements for asbestos in accordance with the Gregorio Bill (S.B. 1678) that was passed during the 1976 legislature session. The definition of "use" in this bill is so broad that, unless the Standards Board decides otherwise, all of the consumer industries would be required to report. Based on the Weston estimate of 140,000 estab lishments in this category, 11,000 California locations in addition to those shown above would be required to report. As a final point, California is considering a sputum cytology requirement for workers older than 40-45 years. The Statistical Abstracts of the United States provides the following age distribution for the male U.S. Labor Force. Age % of Labor Force^ 16-19 20-24 25-34 35-44 45-54 55-64 65 and over1 (1) Based on 57.3 million 9.1 14.2 24.4 18.5 18.3 12.2 3.3 100.0 e workers in 1974. Based on these percentages and the lowest estimate of 100,000 workers exposed to a 1 fiber/cc TWA level shown in Table D, sputum cytology would encompass 43,000 workers older than 40 or 34,000 workers older than 45. Addition of a requirement of 10 years of exposure would obviously reduce these numbers to some extent. The available exposure data is too limited to make an estimate of this reduction. LAM 030191 ABS-012246 lam 030192 ^gS-012247 -17- TABLE D STATE OF CALIFORNIA ESTIMATE OF EXPOSURE LOCATIONS AND EMPLOYEES EXPOSED1l) PRIMARY INDUSTRIES^ UNITED STATES Locations Exposed Workers 103 22,670 CALIFORNIA Location? Exposed Workers 8 3 Minesu',,,, _5 TJC Mfg.u; 16 1814 150 50 2014 SECONDARY INDUSTRIES Except Construction Construction^) Subtotals 248.000 750.000 998,000 1,140,000 100,000-500,000 1,240,000-1,640,000 19.840 60.000 79.840 91,200 8,000-40,000 99,200-131,200 OVERALL TOTALS (ROUNDED) ,000,000 1,300,000-1,600,000 80.000 100,000-135,000 1. Includes only those workers where there is a reasonable possibility that exposures will exceed 1 fiber/cc TWA. 2. U.S. numbers do not include the "Miscellaneous" Industry Segment category. Additional figures shown are specific for California. 3. Based on estimate for regular exposure to 1 fiber/cc or more. LAM 030193 ABS-012248 LIcCADi CL *aio_ ooa>> C>413>O>. > XI -18- CTl vCOM OO N Irt IA 1 OO o co>a a> --c c<0 -- Cl C EO oO cVmCcL CM 4) cr Ol- co tt-) in o o o CM ON O co vO vO o o> -- fO CO -J U"\ vO CM | CO IA col CO o s' Li C 4) > ia <y <u > l_ L Cl 3 V to OC > o o o CM CO o o o --33- o o -3- co -3 Q o CO co ooo ooo CO o o o CM G-3O -- -- o o tn <T\ O O CTl CM -- Oo oo o OO * o cO CM . CM co VI X) c o V- Asbestos F ib e r Usage and P ercent o f Coverage o f Each In d u s try Segment 4> o o o o o o o o o o o A e C3 o </) I- c o o oo oo ft ft CM -3 J- -3 CO -- oo o o CO to CO o ft ft CM OO L* V-- to \D CO -- o ooo o o to o ft r**M OO 'co CO CM vO o o * o o o> o a CD tA oCO 3 3 l/l o V|_ Li (A oo 00 vO CO CO to CM vO to o vD o ro O CM to V-- o r-s o o o *-- V M _o (A < (A c ua <0 0CD) iCnD Li to -- c Li CL Q) o E CL "O 0) c 4> <7 "O a CD jr C a> 4> CL (A to -- u (A oto Li lA i_ 4> Li o <r> Li u >U c u 0) o Li CL E 3c o"O -- Li cc CD u- *-- 0) CL Li E -- X IA CD 4) C- CD 4) *T3 4) 4) 3 CL O V CL 0 C-> C CL 1- <_> CD to 3 O 0c) LAM 030194 o o oc (A (A *-- C L O Li H ft. (A lA A CD CA O O IA Li Li Li Li #-- A tn L Li Li IA 4) (A (A 4) r-- o4> 4) o c 4> 4> V O CD oJO A jtOn -- -- <A JO tA Li L CD A CD CA A -- O < < L. u. CL < O < < 2! 1" CM CO -3" to vO fMft OO CO O ABS-012249 19 Number o f Employees at Various Exposure Levels Primary Asbestos In d u s trie s >* P C co P U VV O uw- Lc O-- > >* z 4J O O %st -X3-1 SO COCO lA os CO WO>A cr\ sO a> \D *> JV0- sO O O fA CO N VO C\ ro XV C 4- -- c 51 -- EL IQ C 4-1 Qj O <s> <0 > cc O uj "vs X ID Uo CUS *01 > 5 o\ lA -33A*" a CO vO X- O-- X* ---3" --1Tb u 4- c *- JZ c -- c o 4) E --c oc >.*l_- --c 4O- eo i/C>J COA LA O CTv CS lA tA fA N O fA -r3A- --> * C o CV UJ 4> > Dtn Xl~ Vo o U~V o cn r- o PA W \0 -u> co CJ LA vO O r*\ > * tprt CO o *53" CO CO cv CO o, o C *J 4-* -- C co D cE -- > cou -- to *-> E. oa --> <D C P UJ c -- J co o^ IOp 3" N J-o lA lA (Tt LA ts O M> eCgT\ rOoA rg eg lam 030195 >u* Oo> v 4-* U(Q -Col oVI CXL "O <U IP 4-> >K cz> O o; i- c VUu to o Cl ABS-012250 It -20- y' Table *-1 Time-Weighted Average Fiber Counts Asbestos Paper Process Step 1 Receiving & Storage 2 Fiber Introduction 3 Stock Preparation U Papermaking 5 Dryer 6 Slit and Calendering 7 Rewind Fiber Count: with Existi Control Technology Typical Ranqe Fibers/cc Fibers/cc 1.0 0.25 - 2.5 1.9 0.3 - 2.8 1.2 <N1 1 o 0.75 0.25 - 1.0 0.75 0.5 - 1.5 1.0 0.1 - 1.6 1.0 0.5 - 1.5 Data Base: Data collected from plants consuming 182,000 tons of asbestos annually, or 53 percent of the Asbestos Paper Segment. LAM 030196 ABS-012251 -21- Table L-2 Time-Weighted Average Fiber Counts Asbestos Cement Pipe Process Step Fiber Receiving & Storage Fiber Introduction Dry Mix Wet Mix Pipe Formation Cure Finishing (Lathes) Coupling Cutoff & Machining Fittings & Specialties Rework Saw . Crushing Fiber Count with Existing Control Technology Typical Range Fibers/cc Fibers/cc 1.0 0.25 - 2.5 . 1.5 0.5 - 3.5 1.8 Oo rv\ CO 11 CO 0 0 oo 1.2 0.75 0.5 0.5 - 1.1 - 2.0 1.75 1.9 2.2 0.6 - L.5 1.0 - 2.25 1.5 - 2.1 2.0 - 2.9 Base: Data collected from plants consuming H*i,000 tons or 100 percent of the Asbestos Cement Pipe Segment LAM 030197 ABS-012252 -22- Table 4-3 Time-Weighted Average Fiber Counts Floor Tile Process Step 1 Receiving 5- Storage 2 Fiber Introduction 3 Blending 4 Banbury Mixer 5 Milling 6 Calendering 7 Embossing 8 Cutting 9 1nspection 10 Packing 11 Scrap & Rework Fiber Count with Existing Control Technology Typical Ranqe Fibers/cc Fibers/cc 1.0 0.25 - 2.5 1.5 0.9 - 4.3 1.75 0.9 - 4.3 1.5 0.75 0.75 0.75 0.75 0.75 0.8 - 4.3 - 0.5 - 0.5 -- Data Base: Data collected from plants consuming 43 t,00 tons of asbestos annually, or 39 percent of the Floor Tile Segment. LAM 030198 ABS-012253 -23- - Process Step 1 Receiving Storage 2 Fiber Introduction & Storage 3 Mixing k Forming or Rol1ing 5 Curing 6 Finishing 7 Adjustment & Printing 8 Inspection 9 Packaging Table kA Time-Weighted Average Fiber Counts Friction Products Fiber Count With Existinq Control Technology Typical Range fibers/cc f ibers/cc 1.0 0.25-2.5 2.5 0A -4.6 2.3 0.2 -8.0 3.3 0.5 - 22.0 1.5 0.5 -3.5 2.0 0.6 -7A O 1 o 1.0 2.0 0.1 -15.0 1.5 1.0 -2.0 Data Base: Data collected from plants consuming 35,100 tons of asbestos, or 60 percent of the Friction Products Segment. LAM 030199 ABS-012254 Table 4-5 Time-Weighted Average Fiber Counts Paints, Coatings, and Sealants Process Step 1 Receiving Storage 2 Fiber Introduction 3 Mixing Compounding 4 Packaging Fiber Count with Existing Control Technology Typical Range Fibers/cc Fibers/cc 1 .0 0.25 - 2.5 2.5 1.5 - 8.0 -- -- Data Base: Data collected from plants consuming 20,500 tons of asbestos, or 30 percent of the Paints, Coatings, and Sealants Segment. LAM 030200 ABS-012255 -26- Table 4-7 Existing Fiber Counts Operation Fiber Introduction Mixing Braiding and Twisting Sheet Formation Cutting Packaging TWA Range Fibers/cc 0.5 - 2.5 0.014 - 1.0 For the basic gasket and packing processes, fiber exposure levels in the fiber introduction area are of the most C9ncern. Where mixing is accomplished with a wetted compound, fiber evolution is low. Data for fiber levels in the braiding, sheet formation, cutting, and*packaging steps were not re ceived in sufficient quantity to estimate employee exposure since these companies surveyed felt that they are complying with the existing standards and to the 2.0 fibers/cc TWA level for July 1976. Table 4-8 Time-Weighted Average Fiber Counts Asbestos-Reinforced Plastics LAM 030201 Process Step1 2 3 * 5 6 7 1 Fiber Receiving 6 Storage 2 Fiber Introduction 3 Dry Blending /* Resin Formation 5 Kneading, Rolling, Etc. 6 Cure 7 Finishing Fiber Count with Existing Control Technology Typical Range bers/cc Fibers/cc 1.0 0.25 - 2.5 2.0 0.5 - 3.0 1.0 0.2 - 1.5 0.75 1.0 0.5 - 1*5 0.25 - 1 .5 0.75 1.0 0.2 - 1.5 0.5 - 1-5 ABS-012256 Table 4-9 tn 4-> c D o o 1. O tn XJ U- -- 4-> OX cn o <0 H t. 0) tn >O < 4- tn X> ft) a -o tn JZ < CJ> ft) :* I ft) E J- 27 o> c o o oo 4-* o * tn >* --a o \ o o. o LA ID ID -- r-- 4- 4-> x o > tn UJ -- v_ u ID ID OO o o ft) -C c _o 4J JZ ooo o o z o z -- o lL LA CM CM CM CM ?o 1--' CM 4-* c-- 3O o - LA O 4-> c u o CM o uO \ o o ft) u> o. tn oo o o o -4" r-- -Q E L. << D ft) \s 1 li_ O JD U. Zz o ooO CM CM -4" ID 4J ID ' O o z o LA 1 o CM o --V ID \ U tn t. o O O o O o o ' O a ft) j- J- J- cn CA > X> V- Li. tn tn ft) Q o ft) o 4J in CL ft) cn c ID o L. o *J 4-1 u tn D *o t-5 oL. U) 4-> cc > L. ft) ft) o JZ ft) oC lx. 1-- CM cn c *o c ft) CO C7> cn cn cn C c cn c cn c -- - c *-- c -- c 4- *-- "U -o c tn > -- X L. -- <D a ID ID ft) L n O to H- ? CO CA -3* LA vO CO couo ft) cl vO cn O Otn *- 0tn) Xto) <0 o n c o o o cn s' CM c ft) E Cl -- 3 cr ft) 4- o a E O i_ 4- ft) tn ---- O X) 4- ID ID O E -- 4- Cl tn Ol ft) < ft) 4- Lo ID z 10 1 U ID < Q\ z cn c *3toi cC o tn 4- c10 CL ip C o 4J c f>t) oCo cn E ft) O oo vi_- a> -a -- o 4- 4oo--1 hXa* *-- tn oo O 4-> <0 tfnt) o4<-o* J<tOn ain ID CO ID ID4- O LAW 030202 ABS-012257 A- ECONOMIC IMPACT FOR BRAKE SERVICE/REPAIR SECTORS - SECONDARY INDUSTRIES -28- o o o o o o o o o fo^. CM v) <n -viDr CM O 0 lO > oCL fftt). -tCo uto1- *o-> -- ft) o o o LT\ CM CM O o o in m o o o > o VmO o o o CM o o o k in ft) -- t/> Ll, o (0 f3t. CL o 1- -C Mft. to CD L. o 0) ooo . -ma* ooo o jx ooo . in 00 Ooo mcn ooo in CM -- CM 2 o CO ft) zo m 4- CL *0TC>) -t/CO> o o o o o o o o o oo oo oo Cft) *- o. -- ft) cd o cn -- oo r- Vvo0 co O o-- "D CL C ft) -- CC o oo OO o O o o \viDnD -a- CTi VO >- 3 o3 c c o o ft) >ft) o T? cftn) Q. oQ_ E UJ X6) X> ft) >* 10 --o -- CL CO X C ft) --o > in -- CD 4- oc u ft) O3 O' ft) ft) O t>***oc CL uEi wn "O ft) c-- in Oa X in 4- C ft) ft) in XE ft) ft) >* tn -- *-- O J0 -- CD Q. E 44 Ifl ft) ft) *-- CD 4-4 CD 4-4 (/) o o l-- l-- --v -o u ft) -- >Q CL o> cfet) c\ ft) in u-- 4-4 > cu ft) ft) E CO JiCn ft) -- JX JO 1CO. 4C-D/ CO mc LAM 030203 ABS-012258 * ^ */. H, * .itiU/mi . tKC ** ' *-A`* * -v* <p 3 .4 MEMORANDUM *.4t DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE PUBLIC HEALTH SERVICE CENTER FOR DISEASE CONTROL NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH 7 TO n .*< .M : The Assistant Secretary for Health Through: ES/PHS_________ Director, CDC DATE: OEC 1 S 1Q7fi U 111,0 FROM : Director, National Institute for Occupational Safety and Health SUBJECT: Evaluation of Data on Health Effects of Asbestos Exposure and Revised a Recommended Numerical Environmental Limits i -) The National Institute for Occupational Safety and Health (NIOSH) ..recommends that occupational exposure to all types of asbestos be controlled so that no worker will be exposed to an airborne concentration of asbestos in excess of 100,000 fibers over 5 pm in length per cubic meter on an 8-hour time-weighted average (TWA) basis. In addition, no worker will be exposed to peak concentrations in excess of 500,000 such fibers per cubic meter of ] air based on 15-minute sampling periods. i4i Previously, in a criteria document transmitted to the Occupational Safety 1 and Health Administration (0SHA), U.S. Department of Labor, on January 21, 3 '/ 1972, NIOSH recommended that occupational exposure to asbestos be limited - 'i i ia to 2,000,000 fibers over 5 pm in length per cubic meter of air, determined as a time-weighted average exposure for an 8-hour workday, and to a peak concentration of 10,000,000 fibers over 5 pm in length per cubic meter, determined by a minimum sampling time of 15 minutes. That recommended standard was designed primarily to prevent asbcscosis. Recognizing that there was then insufficient information to establish a standard to prevent such other asbestos-related diseases as pulmonary, pleural, and peritoneal neoplasms, NIOSH had included in its calculations a safety factor intended to guard against neoplasms more adequately than unmodified environmental limits based solely on prevention of asbestosis. The current recommendation of a stricter standard was formed after review of both the most pertinent publications considered in the 1972 document and papers published during the four years since that document was transmitted to OSHA. The recent literature reviewed has shown that the British standard of ^ t 2,000,000 fibers per cubic meter, adopted in 1969 and implemented in Nay of 1970, has not halted the development of radiographic abnormalities of the chest in workers in asbestos-using establishments. Another study has reported that miners exposed to fibers from amosite asbestos in airborne concentrations of less than 2,000,000 fibers per cubic meter (average concentration 250,000 fibers per cubic meter) have twice the likelihood of the general population of dying from either malignant or nonmalignant respiratory disease. Other papers have demonstrated that the risk of developing cancer after mixed exposure of factory workers to chrysotilc, amosite, and crocidolite asbestoses is dose-related. LAM 030204 i ABS-012259 The Assistant Secretary for Health 2. Furthermore, one paper reported that an excess mortality from lung cancer was found in 65 men who had been exposed to an unmeasured concentration of amosite asbestos for less than one month thirty years previously.. The mortality rate was determined on an age-specific basis. The present indications are that concentrations of asbestos fibers of 100,000 per cubic meter will occur rarely except in the asbestos-processing industry. Asbestos-containing fireproofing and anechoic linings of airducts and plenums, although they are possible sources of asbestos fiber, probably are not major polluters of air within buildings. Currently it is not possible to establish a safe exposure level for the carcinogenic activity of asbestos. Therefore, the exposure values now recommended by NIOSH are based on what N10SH considers to be the lowest concentration at which asbestos fibers can be monitored reliably using phase-contrast fiber counting procedures. After a thorough review and evaluation of all available sampling and analysis methods, NIOSH believes that phase-contrast microscopy is the only generally available and practi cal technique for routine monitoring at the recommended environmental limit. The recommended TEA standard of 100,000 .fibers greater than 5 ym in length per cubic meter of air is intended to (1) protect against the noncarcinogenic effects of asbestos and (2) materially reduce the risk of asbestosinduced cancer. Because it is not possible to specify a safe exposure level for a carcinogen, only a ban on the use of asbestos can ensure com plete protection against this mineral's carcinogenic effect. Therefore, emphasis should be placed on prohibiting the occupational use of asbestos in other than completely closed operations and on substituting other pro ducts whenever possible. Asbestos should be replaced, where technically feasible, by substitutes with the lowest possible chronic toxicities. John F. Finklea, M.D. LAM 030205 ABS-012260 J J <^a/ MEMORANDUM DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE PUBLIC MLALTil SERVICE CliNTEK FOR niSC.NSI: COM KOI. NATIONAL INSUTUTH FOR OCCUPATIONAL SAFETY AM> HEALTH 'O Morton Corn, Ph.D. Assistant Secretary of Labor Occupational Safety and Health Administration Department of Labor 1978 FROM Director, National Institute for Occupational Safety and Health SUBJECT: Evaluation of Data on Health Effects of Asbestos Exposure and Revised Recommended Numerical Environmental Limits According to your request, NIOSH has evaluated available data concerning the health effects of exposure to asbestos. The general conclusion of this study is that all forms of asbestos, both commercial and non commercial, are carcinogenic. All have the capacity to induce pleural and peritoneal mesotheliomas and/or lung cancer in man. In addition, all forms of asbestos have been found to cause asbestosis in man. NIOSH has proposed new environmental limits which are based on this study. These recommend that no worker be exposed to an airborne concentration of asbestos in excess of 100,000 fibers over 5 p in length per cubic meter on an 8-hour time-weighted average basis. In addition, the proposed standard states that no worker should be exposed to peak concentrations in excess of 500,000 such fibers per cubic meter of air based on 15-minute sampling periods. Currently, it is not possible to establish a safe exposure level for a carcinogen. Therefore, recommended exposure values are based on the lowest concentration at which asbestos fibers can be monitored reliably using phase-contrast fiber counting procedures. After a thorough review and evaluation of all available sampling and analysis methods, NIOSH feels that phase-contrast microscopy is the only generally available and practical technique for routine monitoring, although electron microscopic methods are available on a limited scale for more precise research studies. The recommended TWA standard of 100,000 fibers over 5 pm in length per cubic meter of air is intended to (1) protect against the noncarcinogenic effects of asbestos and (2) materially reduce the risk of asbestos-induced cancer. Because it is not possible yet to specify a safe exposure level for the carcinogenic activity of asbestos, only a ban on its use can ensure complete protection against this mineral's carcinogenic effect. Therefore, emphasis should be placed on prohibiting the occupational use of asbestos in other than completely closed operations and on substituting other products whenever possible. Asbestos should be replaced, where technically feasible, by substitutes with the lowest possible chronic toxicities. LAM 030206 ABS-012261 l Morton Corn, Ph.D. 2 The present indications are that concentrations of asbestos fibers of 100,000 per cubic meter will occur rarely except in the asbestos-processing industry. Asbestos-containing fireproofing and anechoic linings of air-ducts and plenums, although they are possible sources of asbestos fiber, probably are not major polluters of air within buildings. This report addresses only the health effects of exposure to asbestos and the proposed environmental limit. NI0SH intends, however, to address formally, as soon as possible, the other provisions of the standard outlined in OSHA's Notice of Proposed Rulemaking dated October 9, 1975, and further comments will be brought to your attention. John F. Finklea, M.D LAM 030207 ABS-012262