Document M5qZ7NBGVzryJbrkaRdnDrnV

U.S. DEPARTMENT OF LABOR Occupational S;i-;y sni Health Administration Washington', d,c. :o:io PLAINTIFFS EXHIBIT WCD-374 nsr`o 5 V%i-5t? 7 November 21, 197-1 FIELD EiEOFtATTOH 52MOPA::DU-'I #74-92 TO: OSHA A ssista n t Ssgional D ire c to rs a rd Area D ire c to rs SUBJECT: Tram olite and Thlc 1 . Background: The attach ed l e t t e r from A ss is ta n t S ecretary o f Labor John H. Stender gives further policy guidelines in regard to tre r o lits and ta lc th a t are not a sb e stifo m o r fibrous. 2 . P olicy Change: -, In order to be considered asbestiform or fibrous the following c r i t e r i a vn.ll be used by th e S a lt la k e C ity Laboratory o f CSKA: A. P a r tic le s must appear to be fib ro u s r a th e r th an as c r y s ta ls or slivers. B. The maximum diam eter o f a f i b e r to be counted i s 3 m icrons. C. The maximum le n g th o f a f ib e r to be counted i s 30 m icrons. D. The length to w idth r a t i o must be 5 o r more to 1, t h a t i s , 5 tin e s or' more longer th an wide. E. . The sep arata o r in d iv id u a l f ib e r s m ust co n tain f i b r i l s o r th e "bundle of stick s" e ffe c t, unless they a re a t a ncnd iv is ib le stag e . A f i b r i l cannot be subdivided and would b e counted, i f i t meets th e o th e r c r i t e r i a . The e le c tro n microscope may be used to prove th e fib ro u s n atu re o f th e p a r tic le s . The le n g th to w idth r a t i o o f 5 o r more to 1 i s n o t meant to imply th a t o th er p a rtic le s are n ot hazardous, 3 . Sample C o llectio n ard Submission-. - I f th e Compliance Safety and H ealth O ffic e r (CSKO) i s reasonably sure th a t the ta lc or trem olita is fibrous or asbestiform , he w ill sample follow ing th e OSHA Sampling Data Sheet #2 fo r a sb e sto s. Goodhue WCD 000045 - 2- In a l l o th e r cases fo r t a l c o r t r e r o l i t e , h e 'v a il (1) sample follow ing th e Sampling Data Sheet =2 fo r asb esto s and (2) sample using the.midget inpincer for r.cn-aseestiferr., ncr.-fibrous ta lc or tre r.o lite . Him impinger samples a re taken, an a i r sairple must be c o lle c te d follow ing CSHl' Sampling Data Sheet =3 fo r c ry sta llin e s ilic a for determining the percent quartz a t the S a lt Lake C ity OSKA la b o ra to ry . Midget in p in g er samples r u s t be analyzed w ith in 24 hours a f t e r . c o lle ctio n ro r tr.e re s u lts to ba v alid . Therefore, arrancements irn st be irade by th e In d u s tria l H ygienist w ith a lo c a l la b o ra to ry ' concerning th e analyses p r io r to rak in g th e in sp e c tio n . 'Lease samples a re not tc ba se n t to th e CSHA L sk craterv , S a lt lak e C itv: they w ill not ba analyzed th e re . I f uhs In d u stria l K ygierust is certain tn a t m e rale cr trem olite is asbestiform or fibrous, in p in g er samples may be em itted frenv the- in sp e c tio n s. ' 4. R esults and In te rp re ta tio n {1) R esu lts from th e in p in g er samples w i l l be used i f th e t a l c o r t r e r o l i t e i s n o n -a sb e stifo m o r ro n -fib re u s . Table G-3 o f 1910,93 would apply. The T ire Weighted Average CL'S.) fo r ta lc cr tre ro lite th at is non-asbestiforn, non-fibreus .i s 20 m illio n s o f p a r tic le s p e r cab le fo o t o f a i r by th e lig h t- f ie ld count method. (2) The la h o ra to ry w ill give two r e s u lts fo r th e t a l c o r t r e r o l i t e th a t is asbestiform o r fibrous submitted fo r analyses of a sb e sto s. One fo r d e f in ite a sb estifo rm f ib e r s meeting th e - c r i t e r i a o f 5 o r more to 1 and one fo r th o se f ib e r s m eeting th e o ld er asbestos c r ite r ia , namely those p a rtic le s having a le n g th to w idth r a t i o o f 3 o r more t o 1. Samples having a 5 o r -more to 1 len g th to w idth r a t i o and meeting th e o th e r . c r i t e r i a o f paragraph $2 P o lic y Chance would mean t h a t fibrous o r asbestiform ta lc or tr e r o lite is present. There fo re , th e standard fo r asb esto s, 1910.93a, would apply. B u s guidance i s temporary and may change a s a r e s u l t o f fin d in g s fro n on on-going NICSH study on t h i s s u b je c t. Goodhue WCD 000046 A / * r - 3Any q u estio n s iray be d ire c te d to l-'x. C harles TcClure, D iv isio n o f O ccupational H ealth Programming, Occupational Safety and H ealth A dm inistration, Washington, D. C. 20210, telephone 202-S61-2725. 'P 'li'k d '.S P. iO tis e b Barry J White Associate /assistant Secretary fo r Eegional Programs Attachment ,i i. n* .) il Goodhue WCD 000047 I^~-,,r^ V ^ lir " t 'i ffl'iWfir>1ny-r-'^''^-'-kVZl ' 1 vT