Document KGZRVjkExBG1bLvzEa320q5r0

FILE NAME: Union Carbide (UC) DATE: 1973 Feb DOC#: UC370 DOCUMENT DESCRIPTION: Internal Report - The Safe Use of 'Calibria' RG-244 A SBESTO S U N IO N CABBIDE CORPORATION M INING & METALS DIVISION THE DISCOVERY COMPANY P .O .B O X 579 NIAGARA FALLS, N . V . 14302 TEL: 736-278-337S I THE SAFE USE OF "C A LIDRIA" RG-244 February 1973 1. Introduction ; Asbestos has re c e iv e d a g re a t deal o f a tt e n t io n and p u b l i c it y in the ; l a s t s e v e r a l y e a r s and has become th e f i r s t s u b s ta n c e c o ve re d b y new OSHA h e a lt h , ; r e g u l a t i o n s * U n f o r t u n a t e l y , much o f t h e . m e d i a t r e a t m e n t o f t h e s u b j e c t has been . e m o t io n a ll y o r i e n t e d and d i s t o r t e d and i n some cases has b o rd e re d on th e s e n s a tio n a l and u n tru e . Many users o f asbestos and products c o n ta in in g asbestos have been m islead re g a rd in g the s a fe ty o f asbestos and what is needed to comply w ith the OSHA requirem ents. T h is summary has been prepared t o pre se n t th e q u e s tio n o f asbestos to xic o log y in log ical perspective. I t covers asbestos toxicology in general and the key features o f the OSHA r e g u la tio n s . Dust count data are presented fo r p o ly e s te r m anufacturing plan ts using RG-244 and f o r fa b ric a to rs during the s p ra y in g o f the re s in and th e g r in d in g o f th e r e s u lt a n t la m in a te s . The - c u rre n t s ta tu s o f the s i l i c a re g u la tio n s is n o te d . Dust c o n tro l methods are . summarized. 2 . Asbestos Toxicology r Asbestos is a generic term covering s ix n a tu ra lly occurring fibrous l m inerals. I t includes c h ry s o tile , c ro c id o lite , am osite, a n th o p h y llite , tre n o lite , ,i and a c t i n o l i t e . C h r y s o t ile is by f a r th e most w id e ly used v a r i e t y and accounts ' | f q r more t h a n 35% o f w o r l d p r o d u c t i o n . I t i s t h e o n l y t y p e p r o d u c e d i n s u b s t a n t i a l j q u a n titie s in the U n ited States and Canada, A ls o o f commercial importance are 1 c r c c i d o l i t e and am osite from A f r i c a and a n th o p h y llite from F in la n d . I t is accepted t h a t a s b e s t o s , l i k e many o th e r f o r e ig n b o d ie s , can cause d i s a b l i n g lu n g damage w hich f o r asb e sto s i s commonly r e f e r r e d t o as a s b e s to s iS . I t is im p o rta n t t o n o t e , how ever, t h a t a s b e s to s is and s t a t i s t i c a l excess o c c u r r e n c e s o f b r o n c h o g e n i c c a r c in o m a ( l u n g c a n c e r ) , t h e tw o m o s t common a s b e s t o s re la te d d ise a s e s, have occurred o n ly in workers w ith long-term exposures to massive concentrations o f asbestos d u st. The ris k of th is type o f exposure is u s u a lly i n asbestos mines and m ills and i n la rg e m an ufactu rin g o p e ra tio n s th a t use q u a n t i t i e s such as 2 0 ,0 0 0 - 3 0 ,0 0 0 pounds p e r d a y . L o n g - t e r m , m a s s iv e exposures a re , o f course, not typ ica l o f polyester resin manufacturing operations u tiliz in g RG-244 where o n ly 300-400 pounds a re dumped a couple o f times a d a y . ^ 1125 a l s o a p p e a r e d i n t h e p u b l i c p r e s s r e g a r d i n g t h e r e l a t i o n s h i p o=LV/een a s b e s to s and m e s o th e lio m a , a r a r e ty p e o f ca n ce r o f th e p l e u r a . In alm ost a ll cases where there is a strong s t a t i s t ic a l re la tio n s h ip between mesothelioma and the in h a la tio n o f asb estos, c r o c id o lite and/or amosite have i Where asbestos exposure has been lim ite d to c h r y s o t il e asbestos ' 1S c h r y s o t il e ) th e re is s tro n g evidence t h a t no excess mesotheliomas : K ill occur. i : /. . rr a r, \ h U L-' -! ' ....., F i n a l l y , th e re is no evidence t h a t the general p u b lic is in any danger from the amount o f asbestos f i b e r in the community a i r . The U .S . National Academy o f Science s t a t e s in an O c to b e r 19 71 p u b l i c a t i o n , "Asbestos - The Need Fo r And F e a s i b i li t y o f A i r P o llu tio n C o n tro ls :" "a t p re s e n t, th e re is no evidence th a t the small number o f f i b e r s fo u n d i n most members o f tn e g e n e ra l p o p u l a t i o n a ffe c t health or lon g evity." T h is does n o t , h o w e ve r, p re c lu d e th e need f o r d e f i n i t i o n and c o n tro l o f man-made em issions i n t o th e atm osphere. The c u r r e n t OSHA re g u la tio n s r e la t in g t o the work area and the fo rth c o m in g EPA re g u la tio n s p r o te c tin g the atmosphere are intended to provide th is c o n tro l. 9 3. OSHA Regulations A f t e r e x te n s iv e h e a r i n g s , a new s ta n d a rd f o r Exp os u re t o Asbestos D ust was p u b lis h e d i n th e F e d e ra l R e g i s t e r , Volume 3 7 , N o . 110 on Wednesday, June 7 , 1 9 7 2 . The b a s ic exposure s ta n d a rd i s an 8 -h o u r tim e -w e igh te d average (TWA) o f S f i b e r s , lo n g e r than 5 m icrom eters, per cubic centim eter o f a i r . The f i b e r l i m i t is t o be reduced t o 2 on J u l y 1 , 19 76 . A peak c o n ce n tra tio n o f 10 fib e rs per cc is not to be exceeded a t any tim e . Note p a r t i c u l a r l y th e use o f th e tim e -w e ig h te d average over the e ig h t-h o u r s h i f t . An o p e ra to r perform ing one o r two s h o r t a d d itio n s o f RG-244 pe r s h i f t , as is t y p i c a l o f p o ly e s te r p ro d u c e rs , w ould have h is exposure du rin g th is dumping time averaged w ith ze ro (o r a low-background le v e l) fo r the re s t o f the s h i f t . I t is im portant th a t th is concept be understood fo r in te rp re tin g the e ffe c t o f in te rm itte n t exposures. 0$* Im p r o p e r i n t e r p r e t a t i o n o f t h e r e g u l a t i o n s has c r e a t e d many m is c o n cepticns about the equipment and procedures needed to use a s b e sto s. I f exposure lim its are not exceeded, there are no fu r th e r compliance requirements except fo r medical exam inations. In te rp rete d l i t e r a l l y , medical examinations are required fo r a ll employees in any " occupation exposed to airborne concentrations o f asbestos f i b e r s . " Some d e f i n i t i o n o f "exp osed" i s necessary s in c e evidence in d ic a te s th a t small amounts o f asbestos f i b e r have e x is te d in the atmosphere f o r m illio n s o f y e a r s . The source o f these fi b e r s would be from the w eathering o f n a tu r a lly occurring surface ou tcrop s. In i t s c r i t e r i a document on asbestos, NI0SK recommended t h a t "exposed t o a s b e s to s " be d e fin e d as "a ve ra g e exposures above one f i b e r p e r cc o r peak exposures above f i v e f i b e r s p e r c c . " A nutrber o f la r g e asbestos users have adopted t h i s as a g u i d e l i n e i n t h e i r o p e r a ti o n s . R e s p ira to rs and spe cial c lo th in g are re q u ire d in th e c o n s tru c tio n trad e f o r the spray a p p lic a tio n o f in s u la tio n and fir e p r o o fin g m a te r ia ls , and fo r the removal o f such m a t e r ia ls . Th is s p e c ia l p r o te c tio n is n o t re q u ire d fo r any o th e r use o f asbestos unless exposure lim it s are exceeded. T h is is also tru e f o r o th e r item s such as s p e c ia lly equipped t o o l s , pro du ct l i m i t a t i o n s , change room s, clo th e s la u n d e rin g and waste d is p o s a l. 4. " C a lid ria " RG-244 in P o lye ste r Resin - D u r i n g t h e l a s t s i x m o n th s , U n io n C a r b i d e has made a s b e s to s d u s t c o u n t measurements a t e ig h t major p o ly e s te r processing p la n ts . Counts have a lso been made d u r i n g t h e s p r a y i n g o f r e s i n c o n t a i n i n g R G -2 4 4 and d u r i n g t h e s a n d in g and g r in d in g o f p a rts produced from such r e s i n . In a l l c a s e s , sam pling and co u n tin g were done w i t h th e equipment and techniques prescribed in the OSHA regulations-. H %1/ fT \J O:j O lr.\' - 2- Resin Compounding O p e ra tio n s : I n th e m a n ufac tu re o f p o l y e s t e r r e s i n w i t h R G -2 44 as th e t h i x o t r o p i c ' a g e n t , 10 -5 0 bags o f RG-244 a re n o rm a lly dumped i n t o th e r e s in i n th e t h i n ta n k . T h i s g i v e s a c o n c e n t r a t i o n i n t h e r e s i n o f 0 . 5 - 1 % . T y p i c a l l y , t h e dump t a k e s p la c e .o ve r a 10-30 minute period several times a day. The re su lts o f dust counts taken in the breathin g zone o f the operator a t e ig h t m an ufactu rin g lo c a tio n s are shown in T a b le I . Samples were c o lle c te d du ring the dumping o f the bags o f RG-244 and represent c e ilin g concentration {not f i b e r c o u n ts . Exa m in ation o f th e data shows t h a t i n a l l cases the asbestos dust le v e ls were f a r below the allow able c e ilin g concentration o f 10 fib e rs /c c . > 5 * prescribed in the 0SHA re g u la tio n s . ` TWA) N o r m a l l y , t h e o p e r a t o r makes o n l y one s u c h dump i n h i s 8 - h o u r s h i f t s o t h a t t h e peak l e v e l s shown w o u ld be a ve ra g e d w i t h much lo w e r v a lu e s i n fin d in g h is tim e-w eighted-average (TWA) exposure. F o r exam ple, i f the operator w e r e e x p o s e d t o t h e h i g h e s t l e v e l f o u n d , i . e . , 2 . 8 f i b e r s / c c . , f o r eve n as much as one h a l f hour d u rin g the dumping o p e ra tio n and to a background le v e l o f 0 .5 f i b e r s / c c . f o r the o th e r seven and one h a l f hours o f h is s h i f t , h is tim e weighted average would b e : TVA ^ 17-6 K 0 .5 ) , 0 . 7 fibers/cc. Th is is w e ll below both the c u rre n t 5 fib e r s / c c . and the 1976 le ve l o f 2 fib e rs /c c . The OSHA re g u la tio n s p rescribe special precautions f o r the disposal o f empty asb e sto s bags and c o n t a i n e r s - i f i n any re a s o n a b ly fo r e s e e a b le use and handling dust le ve ls above the allow able lim its w il l be generated. In two of t h e p l a n t s u r v e y s , d u s t c o u n ts w ere made d u r i n g t h e h a n d l i n g o f t h e empty RG-244 b a g s. The r e s u lts given in Ta b le I I show le v e ls w ell below the OSHA l i m i t s . As w ith the dumping data given p r e v io u s ly , these values were obtained during a c tiv e h a n d lin g o f the bags and would represent peak ra th e r than tim e-w eighted average exposure. . A ll o f the data presented in Table I and I I in d ic a te th a t " C a lid ria " R G -2 44 asb e sto s as t y p i c a l l y h a n d led i n p o l y e s t e r m a n u f a c tu r in g , gives d u s t . ' .l e v e l s w e ll below OSHA l i m i t s . As lon g as t h is is t r u e , dust m asks, p r o te c tiv e c l o t h i n g , change room s, w arning s i g n s , and s p e c ia l bag disposal are no t re q u ire d . Dust m o n ito rin g is re q u ire d to determ ine t h a t le v e ls are v/ith in th e OSHA standards. Spraying P o lye ste r Resin Containing RG-244: u . I t would not be expected th a t spraying a liq u id re sin con tain in g 0 .5-1% o f " C a lid r ia " RG-244 would create any airb o rn e asbestos d u s t. Samples were c o lle c te d d u rin g a sp ra ying operation-, and no asbestos fib e rs were found. -3 - H V v' -I TABLE I AIRBORNE ASBESTOS DUST COUNTS0 ) DURING PUH?IKG OF RG-244 P la n t A B C D E F G H Data Reference -- 1929-46-2 1929-30-2 19 2 9 -5 6 -1 1929-50-3 19 2 9 -2 6 -3 1929-24-2 19 2 9 -16 -1 Description o f Operation Dump Sample Bags Tim e Time Dumoed { M i n .) ( M i n .) 10 10 10 14 9 9 15 21 21 36 12 12 15 8 8 45 20 . 20 10 24 24 28 15 15 S p e c ia l Venti la ti on(2) None None Hood over th in tank opening 'None None None Hood over m ixing area None C EILIN G Concentration F ib e r Count {Fibers/cc. > 5 ^ 1 0 .7 1 .2 D .7 2 .4 0 .5 1 .6 0 .8 2 .8 ^ A l l samples c o lle c te d in the b re a th in g zone o f th e o p e ra to r dumping th e R G-244. . . ' 'S p e c ia l v e n t ila t io n r e fe rs to du st c o lle c tio n equipm ent a t o r near th e dumping area t h a t is s p e c if ic a lly in te nde d f o r d u s t c o n tro l d u rin g th e dumping o p e r a tio n . A ll p la n ts had v a ry in g measures o f o v e ra ll b u ild in g v e n til a t io n . TA3LE II AIR30RNE ASBESTOS DUST COUNTS DURING EMPTY BAG REMOVAL P la n t A 8 B Data Reference --- 1929-40-3 1929-40-5 Description o f Operation Sample ta k e n 3 fe e t above waste disposal drum fo r empty bags. (D u rin g dum ping.) D ir e c tly o ve r empty bag stacking area. Taken d urin g dump. Empty bag s to rag e a re a . Taken d u r in g dump as bags were put in . Sample Tim e {M in .) 10 23 24 Fib e r Count ( F ib e r s / c c . >5*,) 0 .4 0 .6 0 .4 ! it, a i> Sanding and G rin d in g o f P o ly e s te r Resin Containing R G -244: The main use o f t h i x o t r o p i c p o ly e s te r r e s in in th e U n ite d S ta te s is in the m anufacture o f fib e rg la s s re in fo rc e d b o a ts , shower s t a l l s , and other s im ila r la rg e o b je c t s . These products c o n ta in 10-30% fib e r g la s s and th e remainder is m ainly re s in . The o ve ra ll lam inate thus g en erally contains o n ly 0 .4 -0 .7% o f In th e m an ufactu re o f such o b j e c t s , t h e edges and some p o r tio n o f th e surface are g e n e rally sanded or ground w ith a ro ta ry disc g rin d e r. This generates a clo u d o f v i s i b l e d u s t and i t is necessary to determ ine w hether any fre e asbestos fi b e r is present in the c lo u d . To check t h i s , samples were .c o lle c te d a t fo u r locations during the sanding or grinding o f finished polyester p a r t s . The r e s u l t s , given in Ta b le I I I , show no fre e asbestos fib e rs in anv o f the operations. . . J A l l o f t h e s e d a t a a r e b a s e d on Mi H i p o r e f i l t e r c o u n ts b y th e OSHA procedure. In a d d itio n to t h i s , la rg e r samples o f airborne dust were collected d u r in g O p e ra tio n fca n d were s tu d ie d by s p e c ia l s t a in in g and m icroscopic t e c h n iq u e s w i t h v a r i o u s ty p e s o f i l l u m i n a t i o n a t m a g n i f i c a t i o n s up t o 1000X. T h e s e , to o , fa ile d to reveal any fre e asbestos f i b e r . These data e s s e n tia lly confirm th a t p o lye ste r resin containing the usual leve ls o f RG-244 w ill not y i e l d asbestos fib e r counts exceeding the allowable values. . 5. S ilic a Toxicology S i l i c a , in c lu d in g amorphous s i l i c a , is a " ta r g e t" h a za rd o f .the U .S . O ccupational S a fe ty and Health A d m in is tra tio n . The " C r it e r ia Document," which is the f i r s t ste p in u pda tin g th e re g u la tio n s on s i l i c a , is in th e la t e stages o f p r e p a r a t io n by th e N a tio n a l I n s t i t u t e o f O c c u p a tio n a l S a f e t y and H e a lth (NIOSH) The c u r r e n t e xp o s u re l i m i t ( T L V ) f o r amorphous s i l i c a is 20 m i l l i o n p a r t i c l e s per * cubic fo o t. ' - r 6. Dust Control Although the data presented herein ind ica te th at RG-244, a s .i t is ty p ic a lly handled in polyester m anufacturing, generally gives dust levels w ithin th e OSHA s t a n d a r d s , asbestos is an em otion a l s u b j e c t ; and th e lo w e s t p r a c t ic a l le v e ls are most d e sira b le . The b e s t c o n tro l measure f o r t h is typ e o f o p e ra tio n is an exhaust c o l l a r o r d u c t a t the to p o f th e m ixin g t a n k , so s itu a te d to c re a te a vacuum a t th e m anhole w here th e t h i x o t r o p e is a dded . The e x h a u s t system s h o u ld be equipped w ith a f i l t e r to prevent the discharge o f dust in to the atmosphere. A system of t h i s ty p e sh o u ld a ls o reduce s ty re n e fumes in th e work a re a . An a l t e r n a t e p r o c e d u r e i s ari e x h a u s t hood o v e r th e du m ping p o r t . U n io n Carbide uses th is type o f hood in t h e i r m anufacturing p la n t bagging o p e ra tio n s. A fa c e v e l o c i t y f o r th e open hood o f 300 fpm and d u c t v e l o c i t i e s i n the range o f 2500-3500 -fpm work w e ll f o r asbestos f i b e r s . -5 - / * r: o o o r-i O vJ TA3LE III AIR30RNE ASBESTOS DUST COUNTS H ) HADE DURING SANDING OR GRINDING OF POLYESTER PARTS CONTAINING RG-244 Plant Data Reference Description of Operation Sample < Time Special (Hin.) V e n tilatio n ^) I 1929-40-4 O perator sanding fin is h e d 23 (F u rn itu re polyester fu rn itu re parts M o ld e r) c o n ta in in g ,-0.5% RG-244. Hood d ire c tly over grinding area. J 1 9 2 9 - 4 2 - 7 O p e r a to r edge g r i n d in g on 12 (Boat hull c o n tain in g "'0 .5 Yard). R G - 2 4 4 . ( - , 20S5 f i b e r g l a s s ) 1C O p e ra to r edge g rin d in g on 13 p a r t c o n t a i n i n g - j O . 7% R G - 2 4 4 , 20% f i b e r g l a s s . L (Fu m i ture Holder) Operator hand sanding 45 polyester parts containing "'0.05% RG-244. General area sample. None (Outdoors) None (C lo s e d room 8 'x 8 ` 8*.) None L ( Furniture Holder) Large power Sander 45 smoothing p olyester , parts containing "0.05% RG-244. In te g ra l hood ; CEILING Concentration F ib e r Count ( F i b e r s / c c . > 5w) 0 0 0 <0.01 < 0.01 ^ ^Unless otherw ise n o te d , a ll samples c o lle c te d in the breath in g zone o f the ope rato r during the sanding or grinding o f parts containing "C a lid ria " RG-244. (2) . . . 'S p e c ia l v e n t i l a t i o n r e fe r s to du st c o l le c t io n equipment a t or near the dumping area th a t is s p e c if ic a lly intended f o r dust c o n trol during the dumping o p e ra tio n . A ll p lan ts had va ryin g measures o f o ve ra ll b u ild in g v e n t ila tio n . - 6- V sJ \j V Fo r sm all o p e ra tio n s , an a i r - o r flu id -o p e ra te d a s p ira to r w ith a f l e x i b l e pickup hose can be used to remove th e th ix o tro p e from bags. This would p re c lu d e the need f o r c u t t i n g th e end o f t h e bag c o m ple tely o p e n , and would e lim in a te the subsequent dumping and bag-shaking o p e ra tio n . The dust from the discharge o f an a ir-o p e ra te d a s p ira to r w o u ld , o f c ou rse, re q u ire adequate . collection. Empty bags can be disposed o f by packaging them in p l a s t i c bags Each bag o f RG-244 is o v e r -s lip p e d w ith a p o ly e th y le n e bag which can be used f o r th is purpose. La rg e r p la s t ic bags are com m ercially a v a ila b le i f the RG-244 bags are n o t saved. Waste bags can subsequently be burned or given to a re g u la r trash pickup service. Dust which accumulates on t a n k s , f l o o r s , e t c . should be removed w ith a vacuum hose o r washed down w it h w a t e r . B lo w in g w it h a i r can o n ly r e lo c a t e th e d u s t and may cause a i r b o r n e c o n c e n t r a t i o n s t o e x c e e d t h e p r e s c r i b e d l i m i t s . E x c e s s iv e d u s t can be c re a te d by poor work o r housekeeping p r a c tic e s . Workers should be in s tru c te d to handle dusty m aterials w ith care and to avoid ' undue c r e a tio n o f d u s t by s h a k in g b a g s , th ro w in g th e m , e t c . R e s p ira to rs can be w o r n i f d e s ire d and sho u ld be approved f o r the d u s t e n co u n te re d. Exce p t fo r sp e c ial circum stances, re s p ira to rs cannot be used to achieve compliance w ith OSHA re g u la tio n s. . A d d itio n a l in fo rm a tio n about the safe use o f RG-244 can be obtained by c a llin g 716-278-3376 or w ritin g : ~ "C a lid ria " Asbestos Union Carbide C orporation Mining & Metals D ivisio n . P . 0. Box 579 N i a g a r a F a l l s , New Y o r k 14302