Document k9N06BoDVBY7mZeqx1MRgjQEy

m' ' * ALCOA Materinls and Standards Section `Pittsburgh REMOVAL OF REFRACTORY LIKINGS IN ALUMINUM MELTING AND HOLDING FURNACES \' 20.1.7 PAGE 1 I ?r e 1~ * c f j t3 : 1. SCOPE This stanoaro covers precautions necessary ntn removing the refractory lining materials fr.1 * melting ano nolcing furnaces. the pre cautions ' cover a) Pnospnate Oonceo refractory a*.trials ana b) Asbestos containing refrac tory materials. Portions of this stancarc are la*'#" fro r. Osha 1910. JOOl ana.--j,e*ve jr.aystriei -I'y.jiene Aaire. 2. PHuSPMPtt 60N1/ED REFRACTORY 2.1 General. Tnere have been several ern ttiK inciotnts wherein Alcoa employees en gaged in cism.antiiny furnaces have teen ex- ;osec to phosphine. These exposures have teen associated with the use of pnosphate- to~:ec alumina refractories, and in particu lar uv-38 brick anc Ramtlte's 90 Ram. Pine. Rlthough other pnesphate-oonoed alumina re- r:actcries in use in our plants suen as h. k. "otter's hultex-75, Oer.eral Refractories Ai- t e-s>, horth American's Narcal fc5-b, ano fence's Spartan-fi nave not shown any evi- Cr'.te of cas evolution, the potential re- *ii''S. hospha:e tunotd refractory material is c.hn.on.y touno in m-ltiny and t.olOiriy fur naces anc lacles. Ti.e phosphine problem was f.:*.t orouyht to Our attention Curing tne re pair o* a bv-38 hearth that had failed prema Z* v= =T --i turely. In order to minimire tht CuSt genel- - lI at.cn that accompanies dismantling work ana to expedite tne disintegration of tne readtec brick, tne workers wet oown the floor of the furnace. Their use of the jackhammers drought unexpecteo results. Striking the Cv-3e neartn with a JaCk`,Bm,mer procucec minor f.recracker-like explosions. Small maten- li^e flames continued . to burn in tne area Were tne explosions had occurrec. Although a' ocor was notec, it was interoreteo as Pe- i-g the usual acety ler.e-1 ype that is notec 'rrouently During crick removal. bubseouent- -v, sim.ilar Incicents were reportec. because t-- generated gases were spontaneously flan- m : Pit, uhuspnine was suspected early, ar.c it eventually waS positively idefitifieC. Sreteennjes nave also been reported during itroval of brick that contains no pnos- p-ote. Tnerefore, the presence of fireworks is not positive ptoof or tne presence of O'cspnine. On the other hanc. If explosions anc flaming occur, the work's industrial hy gienist, with the aid of a detector tube, should determine whether or not phosphine is present. 2.2 Removal of Refractory. The removal of ispnate-jpnoeo ref ractory materials should se cone in tne dry condition., because this met'00 is usually a very dusty one, the ure o' respiratory protection is recommencec. Respirators fitteo with filters suitable hr .virig nuisance dusts will be satisfac tory. The lesoirators ShuulC br equipped with valves so that, on exhalation, moist treatn cues not contact tne cust col lected on the filters. If for sor.e reason one of these furnaces is wettec cpwn, it will oe nectssary for tne works Ii.-uStriai -ycienist to sa*ple tr.e working area to ins.re t'at there are no haj- ardous concentrations c' pnespnlne. wBncoolers or otner ventilation assists may -_e useful in clearing cut any coots-inatec area. If there is ny 'eta for a rerson to enter a conta-ir.ai ec cits (i.e., ->ere the nj concentration is above tne 0.3 ppm Tlv)____ ne will recuire tersonai protection, either a self-containec air unit or an all-service gas mask. Moisture in tne air can release phosphine from stereo reactec brick following its re moval from a furnace. Therefore it shoulc not De stereo in a confireo place, especially if employees work in tne area. If tnere are any concerns aocut tne safety of me area it will oe a simple matter to sample tne air with a cetector tube. Because of the relatively high toxicity o' phosphine, we must tie a rather conservative position to te asscrec as completely as pos sible that our employees are protected. uismantling of a furnace is an infrequent operBtion of a relatively snort Curation. Apr this reason, chronic exposures just don't exist. Even tne probability of acute expo sures occurring is limited. The chemistry of what happens in the orick is still obscure, water is necessary to release the phosphine from the phosphide in the reacted brick. w-.en wetted, the pnospnicecontalnlng brick releases pnospnine gradual ly. -*ur tnermore, tne spontaneous ignition that ofter. accc-panies tne release of pnospnine results in tne conversion of pnespnire to a much less toxic material, pnespnorous pentoxice. however, it must be noted that even the nor mal humidity of tne air is capable of react ing itr. tne phosphices and leitasirg small amounts of pncspn;nr. Tne refractory yia.-ually loses its reactivity when it is exposed to air. A typical analysis of the gases evplveo from the wettec reacted brick ls^TtJ* nj, 2C\ phj, and 10* other unknewp^-'gases (possibly :,i2* lJ2 ,,h3 etc.) experience nas shown that the analyte's may vary yicely but the Phj concent r^Jr-fon is Just as likely to be higher tnan^ihown above as lower. There fore, Phj url'll a'.ays be the material of prime copdein. The 'crick that proouced the^etfs above re leased Ci.l ft-* per squa^e-^foc! ofSurface ov r a 24-fio-r Perigee'"'^sy e'.: apol at i on .e i ' fiyuie 'hat ^a-^-iu f l* health ouic pro cure v5 f t L-tTf gas, u* v''ich is 1' n e. In -aTite-r to :.ng Sucn a quantity of PLAINTIFF'S exhibit AL-920 ^.LClI'A .. :L r.*.atcria!s and Standards Section Pittsburgh REMOVAL CF REFRACTORY LININGS IN ALL'",IN'JM MELTING AN2 HOLDING FURNACES ^ PAGE 2 c"j con to the Threshold L-e<el Value, 0.3 c:-. it would have tp^be dilutee with .'..COC.uOC ftJ of aj><-- There are a lot of t.-^essej In extrapolating in this manner ire the f igures'shouio not be taken too lit erally^ >*tf^eer, the inference drawn from that e are ceallng itn appreciable ~.0rtlties of a tonic gas. , .^ T-e presence of nh3 .ni not^cause any aotrrciarle interference for those who have cctosic" 5.0 use the Kltaa*a Pmj detector tube to reasure tn>s c<L hydrogen^sulfree, a cas that,'will interfere, was^'riot cetected lr. t'e products given off by^tThe brick. Arsirte a~c stltine -will also .inter fere but they are rot txpeev^d to De^tfresent. The^above Car. re Ir.terpietea to eesn that *hen, saTi.pling t'e cases ^o'rocuced 0/ tne reacteo^brick with a hltaciva cetector tube the length of stain urccucec on tne tube, for all'practical purtcseso'can oe attrlDuteo tp phpspnlne. 2.3 Phosphine Cas. Phpsphine Is a colorless cas with an ooor cescribeo as like that of garlic, cecayed fish, or onions. It nas an auto-ignition temperature of 104 Deg-105 Oeg ;>.C-05 Oeg C), but may Ignite at room temcerat-re Cue to impurities or when dry. Tne relative cersity of saturated air at 25 Oeg C anc 7b; r g is 1.17 (air = 1). (kef. Haz ardous ''i'erSal Safety Lata Sheet No. 7 lb). T'e "ecranism of phosphine intoxication has net been cefinitely established, but it ap pears to cause depression of the central ner vous system and irritation of tne lungs. The symctors of acute phosphine poisoning report ed induce nausea, vomiting, diarrhea, t'irsi, sensation of pressure in the chest, back puirs, Cyspnea, feeling of coldness, and super cr attacks of fainting. 3. 4SS-ZST0S CONTAINING REFRACTORIES CbriA 1910.1001 states that no employee shall be exposed at any time to airborne concentra*. ;trs o' asbestos fibers in excess of 10 fi bers, longer than 5 micrometers, per cubic ce'-t.reter of air. The b hour time weighted a.tra:* airborne concentrations of asbestos 1::trs to wnicn any employee may be exposec v ret exceed 2 fibers, longer than 5 r:.;or-ters per cubic centimeter of air. t- e'er nee Hazardous Material beta Sheet 40 t.r aidlttonal information.) 3.2 Removal Procedures. Initial site oreparation involves taking precautions to contain entralneo asbestos fioers to the lmneciate work area. # "` , "he size of the enclos ure must oe large enougn to contain tne power equipment, an approvec vacuum cleaner, and several 55 gallon specially narked steel crums. OShA 1910.1001 states that employees engaged in the removal or demolition of structures or equipment covered or insulated with asbestos, shall be provided with respiratory equipment and with special clothing. 3.2.2 Clothing, The employer shall pro- vice, anc require tne use of, special cloth ing, such as coveralls or similar whole oody clothing, head coverings, gloves, anc foot coverings for any employee exposed to airoorne concentrations of asbestos fibers, wnicn exceed tne ceiling level prescribed in 3.1. Oisposable coveralls, gloves, hair covering (uneer the hard hats) and respirators ap proved for asbestos shall be worn a*, all times when work is in progress in the enclos ure. The coveralls are to oe taped at tne ankles and wrists. All disposable clcthing is to be removed and clscarced each time a workman leaves tne work area. Shoes must be ibed with a oamp rag or vacuumed so that the are. outside tne enclosure is not contamina ted. before leaving the contaminatec area 'or any reason, tne workmen shall vacuum the protective clothing, remove the head cover ing, unzip tne ccvtralls and carefully peel tr.em off, with gloves ana shoe coverings re maining attached. Tne respirator is removeo last. Trie clsposable clothing and used fil ter cartridges shall be cisposeo of in plas tic Dags, appropriately labeled for asbestos waste. Respirators shall be cleaneo ana sanitized at the end of every shift, workers must wash all skin surfaces that nave been exposed to asbestos before eating, drinking, smoking or leaving work. Any water that is usee for these purposes must be placec in clastic bags ana '.hen into the arums with tne contaminated clothing. no smoking or eating is permittee while in the enclosure. *r . ALCOA 5 4> * Z . c j;-? 5 5j 0 Materials end Standards Section*Pittsburgh REMOVAL OF REFRACTORY LININGS IN A'.'J'IN'J:: NELTJNG AND HOLDING FURNACES 25.1.7 PAGE 3 sealec steel drums shell be afflxeo titn labels tnat read: CAUTION CONTAINS ASbtSTOS fI&ERS fcAA T MINC ASbSTOS OUST MAY CAUSE SERIOUS bOOlLY HARM -t -; /C. :5=i 2 S r : t-c r ; 1 J. _t Caution signs snail be provided and dlsplayeo at each location where airborne concentra tions c.f asoestos fibers may be in excess of exposure limits prescribed in 3.1. 15* Tnese cruirs must then be disposed of in an approved lano fill. Most lane fill facili ties cannot accept this kino of aste so there is an incentive to completely fill the drums. 3.t Outside Contractors. It is imperative that the outsioe contractor *no he is deal ing itn asbestos. It is recomT.enoee that a copy of Alcoa Material Safety Cata Sheet no. AO (asbestos! Oe Included with either the specifications or toe orcer, as well as ver bally calling the contractor's attention to the hararc. iI ~c t jf Tne disposal of all asbestos containing waste = p " material as ell as coritaminated material re- E c 5 = cj'.res special procedures. Ascestos contain- p 3 ; : :r-~ insulation, contaminated refractory ruo- 3 " i. - -It, the usee Cispcsaole clothing, loose ma- ; i r'-crial ?jc<ea up with tne vacuum cleaner, .:i:ny rags, rinse water from tne wiping ; t ? 4 t.. s, and finally tne plastic enclosure Li-. S'-T'.inc snail oe pacKageo in plastic bags .2 * \ tnen sealec in specially mi&rkec steel I .t -:-'sl, USnA states that caution labels snail : : e affixed to all scrap, waste, ceoris, anc 't*er products containing asbestos, or to ; J 3 t't;r containers. All plastic bags ano Alcoa has no direct liability unoer trie as bestos section of UEhA 1510.1C01 for tne con tractor employees anile tne contractor Is cenolisning tne furnace. Tne contractor shoulo oe required to furnlsn appiovec iespiratory equipment ana special clothing for nis employees as notec In OSrniA 1510.1001<c)l2)(iii). The final cleanup of pieces and particles that may contain asbestos fibers snail be bacced and sealed in specially n.arkec steel oruns (see 3.3! and laoelec according to uS-tn 1510. K GH g) (2 ) ( i i). final disposition of tht material shall be as covered ov RCAA.