Document ykzZ1ZGnO53yE3DpgMybx90XD

FILE NAME: Kentile (KEN) DATE: 1970 June 15 DOC#: KEN026 DOCUMENT DESCRIPTION: Report - Dust Measurements - Interim Report Asbestos Fibre Dust Determinations KNT 47 KENTILE FLOORS, INC. B ro o k ly n , New York Dust M easurem ents - In te rim R eport A sbestos F ib re Dust D eterm inations L _l Subm itted by R. A. W illiam s S r. In d u s tria l H ygienist FERTILE FLOORS, INC. Brooklyn, Xev fo rk D ust M easurements - In te rim R eport A sbestos F ibre Dust D aterm inations Several mOnthB ago, as part of our endeavor to provide information cn the degree of asbeBtos dust exposures related to handling of mixed dust at several locations in the Brooklyn plant, 12 membrane f i l t e r dust samples were collected and sent to our Bopkinton laboratory fo r analysis. Pnis work vas in itia ted in December 1969. S ev era l months have e la p s e d sin c e th is stu d y vas i n i t i a t e d . A lthough p re lim in a ry fin d in g s w ere o b ta in e d and d isc u sse d v i t h Mr. G e n tile , no form al r e p o r tin g o f th e s e r e s u l t s was made s in c e i t v a s f e l t a t th e tim e t h a t th e in fo rm atio n ob tain ed v as not s u f fic ie n tly d e f in itiv e to allow sound s c ie n t if i c judgm ent t o he made v i t h r e s p e c t t o th e e x a c t n a tu r e o f th e ex p o su re as f a r ap t h e p r e s e n t TLV o r p r o p o s e d TLV f o r a s b e s to s f i b r e s v a s c o n c e r n e d . K o r d i d v e b eliev e th a t th e d ata vas s u ffic ie n tly sound to perm it reaching conclusions concerned v ith th e e s ta b lish in g o f a standard fo r K en tile o p eratio n s. So t h a t you m ig h t h a v e th e b e n e f i t o f t h e s e p r e li m in a r y f i n d i n g s , i t can h e r e p o rte d t h a t out o f 12 membrane f i l t e r p a p e r sam ples c o lle c te d , c o n c e n tra tio n s o f a sb e sto s fib re s ranged from ^ to 8 fib re s g r e a te r th a n 5 m icrons in le n g th p er m i l l i l i t e r o f a i r . These co n centrations v ere a rriv e d a t by counting s e c t i o n s o f t h e f i l t e r p a p e r s a t 130 d ia m e te r m a g n i f i c a t i o n w ith o u t t h e b e n e f i t of phase contrast illu m in atio n . We i n t e n d t o r e - e v a l u a t e t h e s e sa m p le s -w ith t h e p h a s e c o n t r a s t m ic ro s c o p e an d phase c o n tra st lig h tin g to determ ine i f th e se p re lim in ary fin d in g s a re above o r b elo w t h e s u g g e s te d TLV o f 12 f i b r e s / m l g r e a t e r t h a n 5 m ic ro n s i n l e n g t h . Our la b o ra to ry a t th e p re se n t tim e has th is equipm ent on o rd er; and as soon as i t is o p e ra tiv e , th e se d eterm in atio n s w ill he com pleted. In th e m eantim e, we a r e i n v e s t i g a t i n g t h e p o s s i b i l i t y o f o t h e r m eth o d s t o a s s i s t u s w ith t h e s e determ inations. We ho p e i n t h e n e x t s e v e r a l w eeks t o he i n a b e t t e r p o s i t i o n t o o f f e r comment on th e r e s u lts o f th i s sam pling. Continued - -2 On th e b a s i s o f w h at we h av e le a r n e d th u s f a r , v e a r e s t i l l o f t h e O p in io n th a t th e exposure a t a l l o p e ra tio n s in v o lv in g mixed d u sts should he c o n tro lle d b y m e e tin g t h e c u r r e n t l y e s t a b l i s h e d TLV f o r a s b e s t o s . I t i s s i g n i f i c a n t t o n o te in th is reg ard th e in fo rm atio n co n tain ed in th e Supplem ental D ocum entation o f t h r e s h o l d L im it V a lu e s f o r A sb e s to s (c o p y e n c l o s e d ) , as w e l l a s t h e new recommended chan g e l i s t e d in th e N o tic e o f I n te n d e d Changes f o r 1570 (c o p y aJLso e n c lo s e d ) . I n t h i s new l i s t i n g , th e TLV f o r a s b e s t o s i s lo w e r y e t , i . e . , "5 f ib r s s /m l g r e a te r th a n 5 m icrons in le n g th w ith 10 f ib r e s /m l c e i l i n g o f s tip u la te d d u ratio n end frequency and as m easured by s p e c ifie d p ro ce d u re ." We t r u s t t h a t t h i s b r i e f r e p o r t i n g w i l l b r i n g you u p t o d a te w ith r e s p e c t t o our e f f o r ts aimed a t d eterm in in g th e asb e sto s c o n te n t o f th e mixed d u s t exposure i n y o u r o p e r a t i o n s . We i n t e n d t o co m p lete t h i s w o r t j u s t as Boon as p r a c t i c a l l y p o s s ib le ; and when s u f f i c i e n t in fo rm a tio n i s a v a ila b le , o u r recom m endations f o r c o n tro l p ra c tic e s w ill be made. B. A. W illiaifas Sr. In d u stria l H ygienist Loss P rev en tio n D epartm ent d l - 6/ 15/70 E n cs. -> NOTICE OF INTENDED CHANCES TO APTEAR IN ACCia THRESHOLD LIMIT VALDES OF ATi'Jl'jRNE CONTAMINANTS FOR 1570 _ I'he f o l l o w i n g c h a n g e s and . ' E d i t i o n s t o Lbc TLV B o o k l e t f o r IQQo u e r e r e c o m mended f c r a d o p t i o n by t h e C o n f e r e n c e a t t h e Conn i t t o e 1s p l e n a r y m e e t i n g A p r i l 1 and 0, 1970. Each p r o p o s a l t ; i l l ;er..nln in t h e above s e c t i o n f o r n p e r i o d o f a t l e a s t two y e a r s b e f o r e t r n n s i e r r n L t o th e Recommended L i s t . RECOMMENDED CHANCES ITEM Armonia Ammonium c h l o r i d e Allyl glycidyl ether Asbestos ' FROM C JO purn 1 mg/oP 10 ppn 12 f i b e r s / m l > 5p in le n g th or 2 mppcf Camphor Diethylene triamine Formaldehyde " I n e r t" or Nuisance Mercury . Methyl chloride Aerosols Quarte, mppcf R e s p i r a b l e Mass Sa mpling Lim i t s for T otal Dust Vinyl chloride Wood d u s t ( n o n a l l e r g e n i c ) 2 T2./u? 10 ppm c 5 pps lp mg/cw' Organic compounds C 100 ppm 2 9 O______ Quartz + 5 DO B t/li^ - Q u a rtz + 2 C 500 ppm 10 mg/mP TO 25 ppm _ 10 mg/mD 5 PFTM 5 f i b e r s / m l > 5(i I n length, w ith 10 f i b e r s / ml c e i l i n g o f s t i p u l a t ed d u ra tio n and f r e quency and as measured by s p e c i f i e d p ro c e d u r e 12 mg/m3 o r 2 ppm 1 ppm C 2 ppm 10 ng/m3* Alley 1 compounds 100 ppm 300 Q u a rtz + 10 30 mg/m? efl Q u a r t z + 5 2 0 0 ppm 5 mg/nP * T h l s r e v i s i o n a u t o m a t i c a l l y r e d u c e s a l l o t h e r s u b s t a n c e s l i s t e d a s 15 m g / n ^ I n t h e 1969 TLV B o o k l e t t o 10 n g / n P . . NEW ADDITIONS ITEM Butyl lactate Coal (b itim in o u s ) D1 a 2 i r.on 2-N Di.bu t y Lam i noe t ha no 1 Iren pentncarbonyi Meihylc v c lo p r n : ad i en y 1 manganese t r i c a r b o n y l (as Mn) Rosin fmes . S u b tilisin s (p ro te o ly tic enzymes) PROPOSED LIMIT 1 ppm 2 rne/n'3 0.5 ng/nvJ 2 ppm 0.01 ppm 0 .1 ppm 0 . 1 mg/r.i5 ( a s a l d e h y d e ) 0.0005 mg/mi (as c r y s t a l l i n e enzyme a c t i v i t y ) F o r t h e TLV C o r m i t t e e May 1?70 1963 SL PPLEMENTAL d o c u m e n t a t i o n OF THRESHOLD L1MIT VA LUES ASBESTOS - ALL FORMS C 5 m ppcf (2 mppc.f, tim e-w eighted av erag e), or 12 f ib e r s /m l > 5 i nj e ngi h A sb e sto s is a g en eric te rm th a t ap p lies to a num ber of m in eral s ilic a te s , incom bu. Lie in a i r an d s e p a ra b le into fila m e n ts. T he m ost w idely used in industry is c h ry s o tile , a ... ignesium silic a te from serp en tin e. O ther typeB include am osite (an iro n m agnesium silicate) cro cid o lite (a sodium iron s ilic a te ), tre m o lite (a calcium m agnesium silic a te ) and anthophyllite (also an iron m agnesium silicate). That exposure to asbestos is asso ciated with development of a potentially' disabling p n eu m o co n io sis in m an has b een am ply d e m o n strated by in d u stria l e x p e r ie n c e ^ . 2, 3, 4. 5, 6, 8, 9)_ a th resh o ld lim it of 5 m ppcf w as recom m ended by D re e sse n e t a l. (6), in 1938 a f te r studying 541 em ployees in 4 a s b e s to s te x tile p lan ts w here m a ssiv e e x p o su re s to c h ry so tile o ccu rred . Only 3 doubtful c a se s of pneum oconiosis were found at the tim e of the study in those exposed to dust concentrations under 5 mppcf, w hereas num erous w ell-m arked cases w ere found above 5 mppcf. Counts w ere from im pinger-collected sam p les in ethyl alcohol and d istilled w ater. Both fibrous and nonfibrous p articles w ere counted, but the la tte r greatly predom inated. Although chem ical analyses of collected sam ples of airb o rn e dust co rresp o n d ed to those of s e ttle d d u st, it is b eliev ed that du st counts of p a rtic u la te s by im pinger can be expected to give only an in d irect m easure of the risk of a sb e sto sis because im pinger sam pling collects p articulates other than asbestos. A co n feren ce on the biologic effe c ts of a s b e s t o s ^ ) in 1965 called atten tio n to the v e ry re a l probability that the 5 mppcf lim it recom m ended by D reessen is inadequate to give com plete w orldng-lift-tim e protection against a ll form s of asbestos. M edical data on which the lim its had been based were inadequate; m ore than half of the asbestos w orkers studied w ere under 30 y e a rs of age and thus provided an insufficient exposure tim e for a sb e sto sis to develop. Of th e 105 w o rk e rs exposed to < 5 m ppcf, 82 had w o rk ed C 5 y e a r s ; 101, < 10 y e a r s ; only 4 had > 10 y e a r s ex p o su re. Seven of 36 w o rk e rs exposed to 5 - 9 .9 y e a rs had a s b e s to s is ; 3 of 50 w o rk e rs exp o sed to 10 - 19.9 m p p cf f o r < 5 y e a r s had a s b e s to s is (6) . M o re o v e r it w as a "po in t-in -tim e" study; many of the ill w ere m issing and the dead uncounted, hence not eon sid e re d in the o v er-all evaluation of the lim it. The asbestos conferences^) fu rth e r called attention to the rising worldwide rate of in crease in lung cancer among asbestOB w o rk ers, p a rticu larly bronchial c a n c e rs, and also noted with a la r m a w id esp read incidence of p le u r a l and diffuse m e so th e lio m a s, tu m o rs h e re to fo re c ' e r'h looked and only recently (1959) asso c ia te d with exposure to asb e sto s. The epidem iology of the e a rly cases was especially revealing in pointing out the scope of asb e sto s exposures; many of the m esotheliom a cases had no in d u strial association, but were "neighborhood'' c a se s o r cases tra c e d to u se rs of asb e sto s. E xposures to asbestos extend fa r beyond those of m in ers and m illers of asbestos or textile w eavers, and include carpenters (sawing asbestos board) in su la to rs an d pipe la g g e rs , d o c k e rs handling a sb e sto s cargo, b ra k e -lin in g w o r k e r s , rubb'e compounders and several others. The Com m ittee on Hygienic Standards of the B ritish O ccupational Hygiene Society from an evaluation of m ed ical evidence fro m G reat B rita in and data from the U. S. P u b lic H ealth S e rv ic e Study() has reco m m en d ed the following c r ite r ia for lim itin g ex p o su re to c h ry so tile a s b e s to s a ssu m in g a 1% r is k of c o n tra c tin g asb e sto s d ise a se d u ring a 5 0 -y e a r w orking exposure^ l). Dust Category C h ry so tile C o n cen tratio n 21) Fibers/m l^) Negligible Low M edium High 0.5 0.5 - 2.0 >2-10 > 10 a) A veraged during a 3-m onth period k) G re a te r th a n 5^p in length F rom these c rite ria , a lim it of 100 fib e rs/m l-y e a rs was proposed, hence a lim it of 2 flbers/m l averaged over a 50-year period. In arriv in g at an asb esto s lim it b ased on A m erican experience and considerations applicable to the A m erican industrial scene, the following predom inated. Recent evaluation of the health ex p erien ce in a sb e sto s p lan ts indicated that the 5 m ppcf lim it w as not sufficiently low to protect w orkers exposed for 30 yearB, a period ra re ly exceeded in A m erica. B alzer and C o o p er(12) su p p o rted th is view in a r e p o r t of a sb e sto s is o c c u rrin g am ong in su la ti :i w orker from levels that w ere deem ed highly unlikely to have exceeded a tim e-w eighted average of 5 mppcf. A retro sp ectiv e investigation of the association between lung c a n c e r in asbestos w o rk ers and sm oking by Selikoff et a l. (13) rev ealed th at a sb e sto s n e o p lasias w ere strongly associated with sm okers. In ac c o rd a n ce with th e se findings, th e 5 m ppcf lim it was m ade a c e ilin g v alu e below which a.. concentrations should fluctuate. T his is equivalent to a tim e-w eighted av erag e value of s lig h tly le s s th an 2 m ppcf, a s show n by A y e r(14) fro m the follow ing d e te rm in e d fo r asb e sto s w here 5% of th e sa m p le s only e x c e e d th e 5 m ppcf lim it: % Sam ples Exceeding 5 mppcf A verage C o n cen tratio n mppcf 1 1. 3 2 1.5 _5 1.9 10 2.4 25 4. 5 Inasmuch as the count by im pinger procedure often consists p rim arily of extraneous particulates (textile plants) an alternate fiber-count may be made by the m em brane filte r m ethod using p h a se -c o n tra st illum ination at 430 X m a g n ific a tio n 's ^ p o r the p u rp o se of determ ining significant asbestos exposure, the m em b ran e-filter method in which only fibers g r e a te r than 5 m ic ra (u) in length a rc counted, is recom m ended, On this b a s is , 6 f ib e r s /m il- lilite r g re a te r than 5 n had been found to be equivalent to 1 mppcf. Hence fo r a tim e-w eighted av era g e lim it by count of a s b e s to s p a rtic le s of 2 m ppcf, the co rresp o n d in g lim it b a se d on f i b e rs of sp ecified s iz e is 12 f ib e r s /m l. T h is lim it is intended to red u ce to an in sig n ific a n t ris k , the o c c u rre n c e of a s b e s to s d ise a se am ong those exposed fo r 30 y e a r s to a ll fo rm s of asbestos. There is still asb esto s disease appearing in industry. It is not known to what extent this represents a re se rv o ir effect of past exposures, o r if the 5 mppcf level is still contributing to the disease incidence. F or this reason the 5 m ppcf is recom m ended as a ceiling value (2 m ppcf a s a tim e -w e ig h te d a v e ra g e )u n til a m o re definite value can be e sta b lish e d b a se d on m edical findings. R efere n c es1234567890 1. M e re w e th e r, E . R. A .: J . Ind. H y g ., 12: 198, 239 (1930). P n eu m o co n io sis ^ A bstracts, 1926-1938, Vol. 1 p. 128. ' 2. Wood, W. B ., G loyne, S. R .: L an cet, D ec. 22, 1934, pp. 1383-1385. 3. Fulton, W. B . , D ooley, A ., M atthew s, J . L . Houtz, R. L . : P enn. Dept, of L ab o r and Ind. B ull. 42 (1935). 4. Lanza, A. J . , M cConnell, W. J . , Fehnel, J . W-: Pub. Health Rep. 50, 1 (1935).' 5. Donnelly, J . : J . Ind. Hyg. & T ox. 18. 222 (1936). 6. D reessen , W. C ., D allaV alle, J . W ., E dw ards, T. I ., M iller, J . W ., S a y e rs, R . R .: Pub. Health B ull. No. 24, W ashington, D. C. 1938. 7. ' Lynch, M .: A rc h . Ind. H ealth _11. 185 (1955). 8. Sm ith, K. W .: A rc h . Ind. H e a l t h ^ , 198 (1955). 9. C a rtie r, P . : A rch. Ind. Health 11, 204 (1955). 10. B iologic E ffects of A sb e sto s, H. E. W hipple, ed. Ann. N. Y. A cad. S ciences 132, A rt. 1, 1965, 766 pp. 11. R e p o rt of C o m m ittee on Hygiene S ta n d a rd s, B r it. Occ. Hlth. Soc. "H ygiene Standards for C hrysotile A sbestos Dust" Dec. 1967. 12. B a lz e r, J . L . , C ooper, W. C ., Ind. Hyg. N ews R ep o rt D ec. 1967. 13. Selikoff, 1. V ., Ham m ond, E C. . Churg, V ., J . A m . Med. A ssn. 204, 104 (1968). 14. A y er, H. . : M em orandum to C o m m ittee M em ber Ja n . 1968. 15. A y er, H. E. , Lynch, J . R ., Fanney, J . H .: Ann. N. Y. A cad. S cien ces U)2, A n . 1, p. 274 (1965). CRISTOBALITE* * Use one-half the value obtained from cith er the count or m ass form ula for quartz. C risto b allte, one of the th re e m ajo r c ry stallin e fo rm s of silicon dioxide is stable at high tem peratures and is form ed when quartz or am orphous silica is heated, as in the calcining of diatom aceous ea rth or in the silica b rick industry. G a r d n e r ^ re p o rte d on e x p e rim e n ts in which ra b b its w e re in jected in trav en o u sly and guinea p ig s intraperitoneally with various m in eral d usts. R esponses to cristo b alite w ere m ore s e v e re than from quartz, and the fib ro sis that followed was diffuse ra th e r than nodular. King, Mohanty, H arriso n , and N agelschm idt(2) had sim ila r re su lts in ra ts given in tra tra c h ea l in jections of cristobalite, fused silica, quartz and tridym ite. ' 1 T h e p re se n t reco m m en d ed th re sh o ld lim it is b a se d on stu d ie s in the d iato m ite in d u stry i3 >4) and by analogy w ith the th re s h o ld lim it f o r q u a rtz . R ecen t e x p e rim e n ta l s tu d ie s (5) in a n i m a ls .with d iato m aceo u s e a r th of 61% c ris to b a lite content a t le v e ls of 2, 5 and 50 m ppcf have presented strong evidence foi the need to review' the p re se n t lim it. Although no frank fi b ro s is of the lung developed from any level of exposure in 2. 5 y e a rs , the lifetim e of one of the exposed sp ecies (ra t), th e re was considerable c e llu la r in filtratio n in the lung End hva- linized fib ro tic nodules developed in the pulm onary lymph nodes in 1 anim al sp e c ie s (dog) at the 5 mppcf level with sc a tte re d nodules at the 2 mppcf level. Long industrial m edical experience indicates that the lim it of 5 m ppcf does not po ssess the requisite safety facto r; occasional cases of pneom oconiosis continue to occur a fte r c risto . b a lite ex p o su re s had b e e n re d u c e d to le v e ls a p p ro x im atin g 5 m ppcf(6). Accordingly, a lim it approxim ating one-half that for quartz of the corresponding percentage in the dust is recom m ended as calculated either from the count or m ass form ula. R e fe re n c es123 1. G ard n er, L. U. ; A m . In st. M ining & M etall. E n g rs. T ech. Pub. No. 929 (1938). 2. King, E. J . , M ohanty, G. P . , H a rriso n , C. V ., N ag elsch m id t, G .; B r it. J . Ind. Med. 10, 9 (1953). 3. Sm art, R. H. , A nderson, W. M .: Ind. M ed. & Surg. 21, 509 (1952).