Document Rj5zOxGqj26EZ3oXm6xK3Roya

FILE NAME: Avondale (AVD) DATE: 1971 Feb 18 DOC#: AVD148 DOCUMENT DESCRIPTION: Draft of Manual for Shipyards - Mt. Sinai School of Medicine with Cover Memo SHIPBUILDERS COUNCIL OF AMERICA 1 7 3 0 K S T R E E T IM. W . * W A S H I N G T O N . O .C . 2 0 D 0 S 2 Q 2 | 3 3 0 - 7 7 2 2 F e b r u a r y ' 18, 1971 TO: ACCIDENT PREVENTION COMMITTEE SUBJECT: D raft M anual on Handling 6f Insulation M aterials E nclosed is self-exp lan atory correspondence from Duncan A. H oliday, R esea rch A sso cia te P r o fe sso r at Mt. Sinai School of M edicine on the above subject. W ould a p p re c ia te your forw ard in g c o m m e n ts d ir e c tly to: H arry Howard A ssista n t to the V ice P resid en t B ethlehem Steel C orporation 25 B roadw ay New York, New York 10004 M r. Howard is a m em b er of the Shipyard M anual C om m ittee rep resen tin g the Sh ipbuilders C ouncil of A m erica . I would a lso app reciate your m aking a copy availab le to Sh ipbuilders C ouncil. cc: Edwin H artzm an J. M. C onley, Jr. Thom as J. Defoe John A. Byington W. B. P o w e ll P L A IN T IF F 'S E X H IB IT SBCA 5030 M O U N T SINAI S C H O O L OF M EDICINE oj The City University oj New York F I F T H A V E N U B A N D I OOTH S T R E B T - N E W YORK, N.Y. 1 0 0 2 9 Dtparlmtnt of Community SMldicint Februa ry .9, pTf To: From: Subject: Members o f S h i p y a r d Manual Duncan A. Hol aday ^ Rough D r a f t o f Manual f o r Committee Shipyards Mr. R e i t z e and 1 have composed a rough d r a f t o f a manual o f recommended p r a c t i c e s f o r h a n d l i n g i n s u l a t i o n m a t e r i a l s in shipbuilding, ship repair and shipbreaking. This is enclosed f o r your e d i f i c a t i o n , comments and s u g g e s t i o n s . Thi s d r a f t was p r e p a r e d wi t h t h e e x p e c t a t i o n t h a t t h e commi t t ee members * * -i* , Wwu I u c o l i i i c c I a Lumpu o i u n UJ r _ ir ,_ l. t _ j _ _ ai Io , a u u lu , u c o uu , i iw wr i t e the m a t e r i a l . Ther ef ore, t h i s document is not intended t o be compl e t e - - but s i mpl y a t a r g e t . We p l a n on us i ng p i c t u r e s and design s k e t c h e s of cont r ol pr ocedur es o r equipment where a p p r o p r i a t e . Some o f t h e s e i t ems we have o b t a i n e d from Mr. Man gol d and Mr. Ay, but would a p p r e c i a t e any m a t e r i a l which you may have and s ug g e s t i o n s pn what would be d e s i r a b l e to include, Particularly needed (in our opinion) are discussions of general d i l u t i o n v e n t i l a t i o n and s u b s t i t u t e m a t e r i a l s . Each o f you s ho u l d have s u g g e s t i o n s on t h e s e o r o t h e r t o p i c s , and' you a r e ur ged t o c o n t r i b u t e . We would a p p r e c i a t e your comments by March 1, 1971. A f t e r t h e s e a r e r e c e i v e d , we w i l l r e w r i t e t h e ' manual , snd you a copy and a r r a n g e a me e t i n g a t which we hope to a r r i v e a t a f i n a l form. Sincerely, Duncan A. Holaday Research Associate Professor Recommended P r a c t i c e s f o r Handl i ng i n s u l a t i o n M a t e r i a l s in S,h i p b*u i 1d i n g , Shi p Re p a i r and S h i p b r e a k i n g Introduction A. B i o l o g i c a l e f f e c t s o f a s b e s t o s ( s u c c i n c t summary) B. Tradesmen who a r e expos ed t o i n s u l a t i o n d u s t s (1) I n s u l a t i o n workmen (2) Pipe f i l l e r s , ste am fitters (3) ' Other t r a d e s working in a r e a s where i n s u l a t i o n i s bei ng a p p l i e d o r removed ' C. 1 "ns which g e n e r a t e l a r g e arnuuiii.s o f d u s t (1) Removal o f i n s u l a t i o n ( r i p - o u t ) . (2) Mixing mo r t a r ' (3) Cutting i n s u l a t i o n m a t e r i a l s ( a) On s i t e ........... (b) Fab shop .. ' ; (*t) Cl ean- up and wa s t e h a n d l i n g ' ' (5) Blocking o r hammering on bl ock o r pi p e co v e r i n g * - to seat material ' (6) Warehousing or s t o r a g e 2 * ; ' / Control of A s b e s t o s - c o n t a i n i n g d u st s by use of s u b s t i t u t e materials * ! A. F i b e r g . l a s s f o r b l a n k e t and pad f i l l i n g B. Pi pe c o v e r i n g and b l o c k wi t h r e duc e d a s b e s t o s c o n t e n t C. Use o f m a t e r i a l s t r e a t e d wi t h d u s t s u p p r e s s a n t HI. Reduction o f d u s t by changes in work methods , A. Mi ni mi z i ng hand c u t t i n g a t t h e j o b s i t e s and us e o f down-draft, exhaust-ventila ted tables B. Pr e mi xi ng a s b e s t o s m o r t a r ` d o c k s i d e ' C P r ^ v j a s b e s t o s m o r t a r ir. p l a s t i c uciyi, , D. We t t i n g a s b e s t o s c l ot h, and f i l l e r s b e f o r e pad and blanket fabrication ' I E. The u s e o f drop c l o t h s a t j o b s i t e s % F. C o l l e c t i o n and c o n t a i n m e n t o f w a s t e s as t hey a r e pr oduced 6. Cl ean- up a t end o f j o b o r end o f s h i f t , usi ng vacuum ' cleaners ' . H. Conduc t i ng a l l p o s s i b l e i n s u l a t i o n work in t he shop ' r a t h e r than on s hi pboar d ' I. Packaging of fabricated parts to ship V '3 IV. Reduct i on o f d u s t s by use o f l ocal e x h a u s t v e n t i l a t i o n A. V e n t i l a t i o n o f l a r g e power t o o l s (1) Band saws (2) Gang saws B. V e n t i l a t i o n o f hand power t o o l s ' ' C. Use o f hoods and d o w n - d r a f t t a b l e s f o r pad and b l a n k e t fabrication V. Reduct i on o f d u s t s by ge n e r a l d i l u t i o n v e n t i l a t i o n Vi . Vi I. Cnnl r ni o f numbers p.xnosp.d ' A. S c h e d u l i n g i n s u l a t i o n work t o mi n i mi z e numbers o f other tradesmen in the area B. I s o l a t i n g a r e a s in which i n s u l a t i o n i s bei ng removed C. Use o f u n t r a i n e d men i n c l u d i n g s h i p ' s company, f o r r i p - o u t s h o u l d be h e l d to a minimum. Personal P r o t e c t i v e Equipment ' . A. R e s p i r a t o r s - - g i v e c i r c u m s t a n c e s in which each t ype should be used . (1) P a r t i eu 1a t e ,fi 1t e r i n g (a) Reusahle (b) Disposable , . Vil A ( c o n t i n u e d ) * , (2) Ai r - s u p p l Ied I ( a) A r - 1 ne ' (b) Self-powered ' ' B. P r o t e c t i v e c l o t h i n g VIII. Education of workers Constant train ing and updating of information IX. . * Medical s u p e r v i s i o n ' ' * X. Summary A. . Measures involving l i t t l e c o s t which can immediately ' be adopted B. Those me a s u r e s i n v o l v i n g more c o s t l y e n g i n e e r i n g and cap i ta 1 funds. \ ROUGH DRAFT 2/ 8/ 71 i n t r o d u c t ion ' ..........." ' i Inhalation of asbestos fibers has caused serious injury t o workmen. Many s t u d i e s have found t h a t c a s e s o f a s b e s t o s i s , lung cancer and pleural and peritoneal mesothelioma occur f o l l o w i n g e x p o s u r e t o a i r b o r n e a s b e s t o s . To p r e v e n t t h e s e serious effects, it is necessary to reduce exposure to asbestos dust to the lowest feasible level. Exposures to high concentra t i o n s , even t hose o f only a few mi n u t e s ' d u r a t i o n , should be avoided. ' Handling insulating materials during ship construction, s h i p r e p a i r and s h i p b r e a k i n g o p e r a t i o n s can expos e many pe o p l e Ke s : d e s t h e s e d e s c r i b e d ec i n s u l a t i o n w o i k e i s . P i p e f i t t e r s ' - and s t e a m f i t t e r s may have t o remove i n s u l a t i o n dur i ng t h e i r work and r i p - o u t o f o l d i n s u l a t i o n may be done by any gr oup. F r e q u e n t l y , members o f o t h e r c o n s t r u c t i o n t r a d e s a r e working in t he same a r e a s wher e i n s u l a t i o n i s bei ng a p p l i e d o r removed and are thus also p o te n tia lly exposed to airborne asbestos dus't. Although areas . a >f r e s p o n s i b i l i t i e s w i l l - ................... d iffe r from,yard to yard, one responsible person, perhaps the industrial hy g i e n i s t or the sa fe ty o f f i c e r , should meet with the job s u p e r i n t e n d e n t and the j ob foreman to survey the job before any work i s s t a r t e d . The o b j e c t of t h i s s ur vey would be to. / 2 determine what and where the p o t e n t i a l dust problems will be. Thi s commi t t e e would t hen recommend p r o c e d u r e s t o r educe t h e asbestos dust exposures during the completion of the job. The committee r e p o r t would be a v a i l a b l e to t he c o s t e s t i m a t o r s as well a s t hos e concer ned f o r t he d a y - t o - d a y work s c h e d u l e . . Operati ons which ge n e ra t e l a r g e amounts of dust include: 1. R i p - o u t o f o l d i n s u l a t i o n * 2. Mixing a s b e s t o s mortar 3. Cu t t i n g i n s u l a t i o n m a t e r i a l e i t h e r on s i t e o r in . fab rica tio n shops If. Bl ocki ng o r hammering on b l o c k o r p i p e c o v e r i n g to \ s e a t m a t e r i a 1. 5. Warehousing and s t o r a g e o f m a t e r i a l ' 6. Clean-up and waste handl i ng. P a r t i c u l a r e f f o r t s s h o u l d be made to c o n t r o l d u s t dispersion during these operations to reduce peak exposures and prevent general contamination of the atmosphere of the t J work a r e a . v '3 . The f o l l o w i n g s e c t i o n s o f t h i s manual d i s c u s s in d e t a i l p r o c e d u r e s which have been used to reduce a t mo s p h e r i c ' . c o n t a m i n a t i o n by a s b e s t o s d u s t . These p r o c e d u r e s have been a s s e mb l e d from s e v e r a l s o u r c e s wi t h ma j o r c o n t r i b u t i o n s made by t h e pr ogr ams d e v e l o p e d a t t h e Puget Sound and Long Beach Naval S h i p y a r d s . ' ' I 1. Cont r ol o f A s b e s t o s - C o n t a i n i n q Dusts by Use o f S u b s t i t u t e Ma t e r i a 1s . Substitution of materials containina. less asbestos f i b e r o r no f i b e r a t a l l , i s becoming more common in s h i p construction. Before a material is substituted for asbestos, c e r t a i n p o i n t s must be c a r e f u l l y c o n s i d e r e d . From a h e a l t h ' .point of view, one must guard a g a i n s t t h a t which has happened in o t h e r environmental s i t u a t i o n s -- where in the h a s t e to r i d s o c i e t y o f a known p o l l u t a n t , a s u b s t a n c e whose p o t e n t i a l h a z a r d s a r e unknown has been s u b s t i t u t e d . A second c o n s i d e r a t i o n must be: wi l l the new m a t e r i a l meet engineering s p e c i f i c a t i o n s and will i t perform adequately under conditions of use. " b M a t er i al s containing reduced amounts of asbestos have been used in the following ap p l ic a ti o n s : / A. Fiber g l a s s for blanket and pad f i l l i n g Amosite blanket covered with asbestos cloth is a . s t a n d a r d m a t e r i a l f or making val ve and f l ange pads. Sub s t i t u t i o n of the proper grade of f i b e r g la s s as a pad f i l l e r not only reduces asbestos dust during fabrication and i n s t a l l a t i o n but a l s o tends to lessen the problems during subsequent " r i p - o u t " .- Asbest os c l o t h which has *w-w----.--i. . T -wl -iL . wwu h i i_i \ w - J . . r - --------------- , ------------------------ -- ?i -^ u- , v. u- . I i1 u- 1u1i-c u- n u 1 1 3 use should a l s o be encouraged. B. Pi pe coveri ng, and b l o c k w i t h r educed a s b e s t o s c o n t e n t Over t he yea r s t he ma n u f a c t u r e r s of calcium s i l i c a t e m a t e r i a l s have been s t e a d i 1y reducing the per cent age of asbestos f i b e r in t h e i r material. Serious conside.rarion should be given to those pr oduct s co n t a i n i n g lower amounts of asbestos fib er, Several B r itis h firms have introduced / , j a s b e s t o s - f r e e c a l c i u m s i l i c a t e b l o c k and p i p e c o v e r i n g . To date, however, th is material has not been adequately evalu a t e d in t h e Uni t e d S t a t e s t o d e t e r mi n e how i t wi l l per f orm in use. 5 111. Re duc t i on o f Dust by Changes in Work Methods , - ' In many o p e r a t i o n s , changes in work p r a c t i c e s wi l l j ' reduce dust d i s pe r s i o n very s i g n i f i c a n t l y . All of the pro cedures discussed in th is section have been u t i l i z e d and found to be e f f e c t i v e . " A. Mixing A s b e s t o s Mor t ar This operation h a s 'usually been done a t the job s i t e . While t h e t i me s p e n t in mi xi ng i s q u i t e s h o r t , c o n s i d e r a b l e d u s t is p r oduc e d. A t e s t e d method o f c o n t r o l is to mix t h e mor t ar dockside, package the mixed mo r t a r in several con t a i n e r s for t r a n s p o r t a t i o n to the job s i t e . Mortar is a v a i l a b l e packaged in s e v e r a l s i z e s of p l a s t i c bags which have a ' spout through which water is introduced. * \ Sufficient water is added to moi s t en the morta r; a f t e r pr emixi ng, the bag is opened and the remaining wat e r added. The c a r t o n in which bag is packaged serves as a mixing box and waste cont ainer. Either of these methods e l im in a te s dust d i s pe r s i o n a t the job s i t e . B. P r e - c u t t i n g p i p e c o v e r i n g and b l o c k in t he f a b r i c a t i o n shoo Hand- cut t i ng o f pi pe coveri ng and block should be kept to an a b s o l u t e minimum. Bend s e c t i o n s , p i p e c o v e r l e n g t h s and b l o c k s s h o u l d be c u t in t h e f a b r i c a t i o n shop on e x h a u s t - v e n t i 1a t 6 J equipment. ' / / The c u t s e c t i o n s a r e d i p p e d ' I n wa t e r , packed in p l a s t i c bags which ar e then labeled. This procedure` insures 4 - 'I t h a t t he c u t s e c t i o n s a r e s t i l l damp and r e l a t i v e l y d u s t - f r e e when t he y a r e a p p l i e d . ' . \ ' C. P r e - s c o r i n g b l o c k s. I n s u l a t i o n b l o c k s s houl d n o t be s c o r e d a t t h e j o b s i t e . Blocks which have been p r e - s c o r e d by t h e manu f a c t u r e r can be purchased, or s t a n d a r d blocks can be scored in v t h e f a b r i c a t i o n shop u s i n g an e x h a u s t - v e n t i l a t e d gang saw. i 1- . . . . . . II*.. *. j . I. u i n o m a t i uvj i p u Q 5 3 c n l u i i c q Mi U i C j u v p . Some p i p e a s s e m b l i e s a r e q u i t e i n t r i c a t e and a r e t r o u b l e some t o l ag w h i l e in p l a c e . A s a t i s f a c t o r y method o f doing t h e s e j o b s , p a r t i c u l a r l y d u r i n g s h i p r e p a i r , i s t o remove t h e assembly in c o n v e n i e n t l y s i z e d s e c t i o n s , t r a n s p o r t them to the shop. Here t he o l d i n s u l a t i o n is removed, any n e c e s s a r y r e p a i r pe r f or me d and t h e c ompl e t e d s e c t i o n r e - l a g g e d . Not o n l y is d u s t d i s p e r s i o n r educe d, b u t i t i s much more c o n v e n i e n t to r e - l a g t h e s e c t i o n in t h e shop t han when i t i s in p l a c e s h i p b o a r d . 7 / E. H a n d -cu ttin g a t lob s i t e s . j ` Some h a n d - c u t t i n g a t j o b s i t e s i s u n a v o i d a b l e . Dust d i s p e r s i o n can be r educed to a minimum by doing a l l sawi ng on a d o wn d r a f t t a b l e . T h e d e s i g n o f such a t a b l e i s shown in Fi g. ___ . A smal l i n d u s t r i a l vacuum c l e a n e r s e r v e s as an ai r- mover . A p l a s t i c bag under t h e t a b l e c o n t a i n s the l a r g e r dusts and wastes. ' . p F a b r i c a t i o n of "pads and b l a n k e t s . Where p o s s i b l e , pad f i l l i n g and a s b e s t o s c l o t h s h o u l d - be done In l a t e r a l l y v e n t i l a t e d hoods. In a l l cases both t h e f i l l e r and t h e a s b e s t o s c l o t h s h o u l d be dampened b e f o r e u s e . See F i g s . ____ ____ ' 6. - Housekeeping and Clean-up . . Area and atmospheric cont ami nation with a s best os dust can be reduced g r e a t l y by m e t i c u l o u s a t t e n t i o n to t h e c o n t r o l o f d u s t and l a r g e r w a s t e s . Drop c l o t h s s h o u l d be p l a c e d on the deck'under each working area to prevent spread of wastes. Scrap should be dropped into p l a s t i c bags as i t is produced 8 r a t h e r t han on t h e deck t o be p i c k e d u p - l a t e r . Work a r e a s s houl d be vacuumed a t t he lunch br e a k and end o f the- s h i f t . tf In a l l . p o s s i b l e ' i n s t a n c e s , t h e workmen s h o u l d be r e s p o n s i b l e f o r c l e a n i n g t h e i r own a r e a s . Where work r u l e s p r o h i b i t t h i s , t h e c l e a n - u p men s h o u l d be u n d e r t h e s u p e r v i s i o n and c o n t r o l o f the i n s u l a t i o n foreman to insure proper a t t e n t i o n to t h i s very important' matter. . , IV. Re duc t i on o f Dusts by Use o f Local Exhaus t V e n t i l a t i o n _ A. V e n t i l a t i o n o f l a r g e power t o o l s . . Band Saws ' The e x t e n s i v e use o f band saws both in docks i de f a b r i c a t i o n shops and on l a r g e r s h i p s ( a i r c r a f t c a r r i e r s ) ' * * in t h e v e s s e l i t s e l f , make e m i s s i o n s from band saws a ma j or s o u r c e o f a s b e s t o s d u s t . Cont r ol d e v i c e s f o r such saws have been known f o r y e a r s and a r e r e l a t i v e l y s i mp l e d e v i c e s . Conventional low v e l o c i t y , high volume systems using a n e g a t i v e p r e s s u r e bag house a r e u s u a l l y more p r a c t i c a l in a fixed i n s t a l l a t i o n 'fabrication shop. IV A ( c o n t i n u e d ) Because some d e g r e e o f p o r t a b i l i t y i s d e s i r a b l e in a temporary shipboard fabrication area, a high velocity, low volume u n i t i s d e s i r a b l e . ( Fi g. ________ ) \ This type of u n i t can a l s o be designed to control dust e m i s s i o n s from t a b l e saws and gang saws. Because o f i t s p o r t a b i l i t y , high v e l o c i t y u n i t s can a l s o be used to perform v a r i o u s housekeeping t a s k s on j o b s i t e s . " >< < . - r I. . _ , i ___ . . . . . _____ l . ' . V C I 1 L I l a L M J I I W l I R . I I U y w v < v . i > .w w . >i . High v e l o c i t y , low volume c o l l e c t i o n systems a d e q u a t e l y h a n d l e most smal l power t o o l s . Saber saws f o r c u t t i n g p i p e ~ I . cover i r . g and, r o t a r y saws f o r c u t t i n g a s b e s t o s cement boar d ar e well c o n t r o l l e d with these systems. (Fig. ) 10 Vl# , * . ' ) ' Cont r ol o f Number o f Workmen Exposed ' - a . Schedul i ng o f i n s u l a t i o n work . * - - " ' --- i, . , Standard industrial hygiene practices call for isolating operations which contaminate the atmosphere with toxic m a te r ia l s Area's where i n s u l a t i o n work i s b e i n g done s ho u l d be i s o l a t e d by p l a s t i c c u r t a i n s o r o t h e r means. Whenever p o s s i b l e , work s h o u l d . be scheduled to minimize the numbers o f o t h e r tradesmen in the a r e a . Ship c o n s t r u c t i o n o p e r a t i o n s a r e more r e a d i l y scheduled ^than e r e s h i p r e a p i r o r s h i p - b r e a k i n g j o b s . However, e ve r y ... v v n \ e f f o r t s h o u l d be made t o keep t h e number o f men exposed a t a minimum. In p a r t i c u l a r , r i p - o u t o f o l d i n s u l a t i o n s houl d $ a-lways be i s o l a t e d and i f n e c e s s a r y pe r f o r me d on an o f f - s h i f t . T r a i n e d workmen s u p p l i e d wi t h p r o p e r p r o t e c t i v e equi pment shoul d al ways be used f o r r i p - o u t work. VII. Personal P r o t e c t i v e Equipment In a d d i t i o n t o- d u s t - s u p p r e s s i o n and dust control pro cedures, personal protective equipment is often necessary to reduce e x p o s u r e and l i m i t t he s p r e a d o f c o n t a mi n a t i o n . The equipment des cr i bed below is used n c ont r ol programs. A. P ro te ct i v e clothing . Protective clothing is required to prevent carrying a s b e s t o s o u s t i n t o l o c k e r rooms t h u s e xpos i ng o t h e r workmen and e v e n t u a l l y i rfco i n s u l a t i o n w o r k e r s ' homes. A s a t i s f ac t or y type of p r o t e c t i v e cl othing c o n s i s t s of resin impreg nated paper c o v e ra ll s . These are inexpensive, readily d i s posable, and eliminate laundering . and p il ferage pr obl e ms . They a r e worn . for one s h i f t , t hen removed and ^placed in p l a s t i c bags for disposal with other asbestos-con taining wastes. These coveralls provide s u f f i c i e n t protection for al l but extreme conditions. \ 12 B. R e s p i r a t o r y p r o t e c t i v e equi pment Even i f d u s t s u p p r e s s i o n and d u s t c o n t r o l p r o c e d u r e s a r e u s e d , some o p e r a t i o n s g e n e r a t e so much d u s t t h a t i t is impractical to maintain atmospheric concentrations of asbestos f i b e r s below t h e Th r e s h o l d Li mi t Value (7LV), and r e s p i r a t o r y p r o t e c t i o n must be provided to the workers. A v a r i e t y of r e s p i r a t o r y p r o t e c t i v e equipment is a v a i l a b l e from which devices s u i t a b l e f o r v a r i o u s s i t u a t i o n s can be s e l e c t e d . American Nation Standard Z88.3-1971, Saf et y Guide f or Re s p i r a t o r y P r o t e c t i o n Against Asbestos-Containing Dusts' should be r e f e r r e d ' t o for de- WM tWV* I | t I ^ -4-1-4--I-U- -Ui-:I --}| t , ^ Air-supplied respirators -Extremely dusty j o b s , such as r i p - o u t of old i n s u l a t i o n where d u s t c o n c e n t r a t i o n s exceed 10 t i mes t he TLV, r e q u i r e use of a i r - s u p p l i e d r e s p i r a t o r s which will d e l i v e r clean, d u s t - f r e e a i r t o a f a c e p i e c e o r hood. Two g e n e r a l t ype s a r e av a ila bl e; a i r - l i n e and self-powered. (a) A i r l i n e r e s p i r a t o r s in which a i r is supplied / to a hood give the greatest degree of protection. A i r i s f e d t o t h e hood from a compr es s ed a i r l i n e . The a i r source must be located in an uncontaminated area and t h e a i r must be f i l t e r e d t o remove o i l and w a t e r ' 13 mi st s before del i ver y. P l a s t i c , disposable hoods are a v a i l a b l e commercia 11y . P r e f e r a b l y t he a i r l i n e should be f as t e n ed to the hood with a ^ u i c k - d i s c o n n e c t f i t t i n g , (b) Self-powered a i r - l i n e r e s p i r a t o r s A i r - l i n e r e s p i r a t o rs connected to a compressed a i r s u p p l y impose l i m i t a t i o n s on movement, and t h i s l i m i t a t i o n can be troublesome. Self-powered r e s p i r a t o r s do n o t impose such l i m i t a t i o n s , but do add t o t h e e q u i p ment which maintenance. t h e workman must c a r r y a n d . r e q u i r e c a r e f u l - . M LL B a t t e r i e s must be r e c h a r g e d a^-t-e-t5r-ea-e-b--u-s-e, f i l t e r s replaced and o t h e r maintenance done r o u t i n e l y. Workers u s u a l l y a tors . prefer these devices / to air-line respir' 2 . Pa r t i c u 1a t e - f i 1 t e r i ng r e s p i r a t o r s ' There a r e s e ve r a l t ypes of p a r t i c u l a t e - f i 1t e r i n g re sp ir a to rs. Those equipped with a half-mask facepiece are c o n s i d e r e d most s u i t a b l e f o r us e by i n s u l a t o r s . Only t h o s e appr oved f o r p r o t e c t i o n a g a i n s t a s b e s t o s u s t by t he gover nment -agency r e s p o n s i b l e f o r t e s t i n g r e s p i r a t o r s should be used. These d e v i c e s a r e recommended f o r p r o t e c t i o n in t h o s e s i t u a t i o n s where t he a t m o s p h e r i c conce'n t ra t i on o f a s b e s t o s f i b e r s does not e xc e e d 10 t i mes t h e TLV. AH t he r ecommendat i ons f o r r e s p i r a t o r ' , f i t t i n g , t r a i n i n g o f workmen and m a i n t e n a n c e , d e t a i l e d in Z88.3-1971 snould be followed, (a) Reusable p artic u late f i l t e r i n g respirators A variety of reusable particulate filtering respira t o r s a r e a v a i l a b l e . Tc ( i n s u r e p r o p e r f i t t i n g , s e v e r a l ' d i f f e r e n t makes s houl d be a v a i l a b l e from which t h e worker can s e l e c t one. No one model r e s p i r a t o r f a c e p i e c e w i l l f i t all faces. Routine maintenance is absolutely necessa to replace clogged f i l t e r s and leaking inhalation or ex . I h a l a t i o n valves. Un-maintained r e s p i r a t o r s can be booby t ra p s . > (b) Disposable p a r t i c u l a t e f i l t e r i n g r e s p i r a t o r s ^ Operation o f an adequate r e s p i r a t o r maintenance pr ogram can be t r o u b l e s o me and, i f o n l y a few men a r e involved, impractical. Disposable respirators are ; a v a i l a b l e which a r e d e s i g n e d t o be worn f o r no l o n g e r than one s h i f t and then discarded. .\ ' Inherently, these devices are not as r ugged as a resuable r e s p ir a t o r and " no a t t e m p t s h o u l d be made to us e them l o n a e r t han one 15 Education and Training * No d u s t c o n t r o l pr ogram can be ' e f f e c t i v e u n l e s s work men and s u p e r v i s o r s u n d e r s t a n d t h e h a z a r d s a s s o c i a t e d wi t h t h e / * jobs, the sources of the hazards and the reasons for following recommended p r o c e d u r e s c a r e f u l l y . - Underst andi ng i s o n l y o b t a i n e d by educat i on of personnel and t r a i n i n g in c o r r e c t o pe ra t ing procedures. For an education and t r a i n i n g program to be s u c c e s s f u l , both management and l a b o r must be concerned and p a r t i c i p a t e . As wi t h a l l s a f e t y pr o g r a ms , i t i s e s s e n t i a l t h a t f i r s t - l i n e s u p e r v i s o r s be i n t e r e s t e d in. and c o o p e r a t e in the work. . The harmful e f f e c t s * trolling asbestos dust are of neglect of procedures for n o t a p p a r e n t f o r many y e a r s . I con There f o r e , i t i s more d i f f i c u l t t o c o n v i n c e workmen o f t h e n e c e s s i t y of following r ul es for working with i n s u l a t i n g m a t e r i a l s .than i f phys i c al hazar ds were involved. However, those s h i p y a r d s which conduct education and t r a i n i n g programs r epor t good success. i ' Education in hazards associated with use of insulating . * . m a t e r i a l s and i n s t r u c t i o n in c o r r e c t work p r a c t i c e s should be v