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72030 Federal Register / Vol. 45, No. 212 r Thursday, October 30, 1980 I Proposed Rules
<br /> acetate.(Flueper and Payne.1982: hexavalent chromium salts are very landfill or impoundment disposal
<br /> Maltoni,1974). soluble and therefore have high situations,since these are typically
<br /> It is further agreed that only migratory potential, anaerobic environments. (Ham,1979.)
<br /> hexavalent chromium presently is Groundwater and leachate monitoring Monitoring data submitted in comments
<br /> known to pose a serious threat of data submitted by various leather likewise supports the conclusion that
<br /> mutagenicity.Chromuim compounds tanners appear to confirm the relative oxidation of trivalent chromium is
<br /> induce chromosomal abberrations in immobility of trivalent chromium under unlikely when these wastes are land
<br /> human and animal leukocytes, and normally-occurring waste disposal disposed.(See Comments of Ailey,
<br /> mutations in bacteria and yeasts(EPA, conditions.{,See,e.g., Comments of Young&Baumgartner.Inc.,July 11,19130,
<br /> 1978: Petrilli and deFlora,1977, 1978; Tanners'Council of America,August 18, Comments of Satz Leathers,Inc.,July 14.
<br /> Nakumoro,1978).in these studies. 1980,pp.7-13;Comments of Dr.Robert 19m,exh.B.)'
<br /> trivalent chromium compounds have a M. Lollar,Technical Director of Tanners' Given the relatively low toxicity of
<br /> weak response.while hexavalent Council,August 12,1880,pp.0-7.]In trivalent chromium,its low migratory
<br /> compounds show significantly higher addition,the Agency has obtained potential,and the lack of indication of
<br /> activity. groundwater and leachate monitoring potential for oxidation under usual land
<br /> Acute and chronic toxicity problems data From sites accepting large disposal conditions, the Agency does
<br /> associated with exposure to hexavalent quantities of tannery waste(which not believe that land disposal of
<br /> chromium include penetrating skin wastes contain high concentrations of trivalent chromium-containing wastes in
<br /> ulcers,perforation of the nasal septum, trivalent chrome),in some cases for long common landfill or impoundment
<br /> inflammation of the larynx,as well as periods of time(from 20 to 89 years). situations poses a present or potential
<br /> damage to kidneys and lungs.(Casarett These sites show no evidence of hazard to human health or the
<br /> and Doull,1979;NAS, 1574;NIOSH, chromium contamination of environment via soil migration to
<br /> 1975:Bovett et al.,1977.)These effects groundwater.(Comments of Berwick groundwater.We therefore believe it
<br /> do not occur upon exposure to Sewer District,June 30.1980;Comments necessary to recognize a distinction
<br /> chromium(III).The only well- of Irving Tanning Co.,July 15,1980.) between tri-and hexavalent chromium-
<br /> documented adverse consequence of Groundwater contamination did not containing wastes when land disposed.
<br /> exposure to trivalent chrome is allergic occur even in cases of prolonged worst- Our research indicates,however,that
<br /> dermatitis[also a property of case management of trivalent chromium- trivalent chromium oxidizes to the
<br /> Hexavalent chromium compounds_) containing wastes(see Comments of hexavalent form when materials
<br /> (Casarett and Doull,1979)' Wolverine World Wide.Inc..August 15, containing c romiurn(111)are
<br /> Various direct applications of 1980,Attachment 1,pp.2,9-13 incinerated or similarly treated by a
<br /> trivalent chromium 10 humans are (improperly sited landfill with high destructive oxidation process.The
<br /> actually considered to be desirable. water table and permeable soil co- incineration ash will certainly be
<br /> Trivalent chromium is required for disposing tannery wastes with other contaminated with chromium (VI)
<br /> proper metabolic functioning.It serves industrial wastes without any particular (Comments of Tanners'Council of
<br /> as a cofactor for the action of insulin, precautions still does not show evidence America,supra. p.6),and we expect
<br /> and is necessary for normal glucose of trivalent chromium groundwater that hexavalent chromium will be
<br /> utilization(Toepfer,et al..1977).The contamination)). present in incinerator emissions as well
<br /> Food and Drug Administration also has C.Potential of Trivalent Chromium to (U.S.Dept.of the Interior,1979).As a
<br /> approved the use of trivalent chromium- result,we believe that chromium-
<br /> containing pigments in cosmetics.(21 oxidize el pingHexth lent sent Chromium bearing wastes(i.e., wastes containing
<br /> CFR 73.2326 and 73.2327.)No such In developing the present regulatory both valence types)continue to require
<br /> applications of hexavalent chrome have regime based upon total chrornium,the Subtitle C regulation when managed by
<br /> been approved,nor are they considered Agency was aware of the differing incineration or similar processes.Our
<br /> to be beneficial. potentials for hazard of tri-and contemplated regulatory approach for
<br /> Thus,at the present time,there are hexavent chromium,and also of their these wastes is described in Part H.C
<br /> well-recognized distinctions between differing migratory potentials. Our below.
<br /> the,human health and environmental concern was that trivalent chromium,
<br /> hazards posed by tri-and hexavalent under waste management conditions, D.Impact of the Proposed Distinction
<br /> chromium. could oxidize to the hexavalent form, On Ocher Regulatory Programs
<br /> which would render it highly mobile and We note,at this point, that certain
<br /> R.Migratory Potentials of Trivalent and toxic.(See, e.g.,U.S.EPA,Listing other of the Agency's regulatory
<br /> Hexuvolent Chromium Background Document for Leather programs regulate on the basis of total
<br /> Trivalent chromium appears to have Tanning and Finishing Industry,pp.733— chromium.Our purposed action involves
<br /> significantly lower migratory potential 34.May 2.19W.) Further analysis only the hazardous waste management
<br /> than hexavalent chromium,and to have indicates,however,that such oxidation program,,and is based on a perceived
<br /> significantly less mobility should it is not likely to occur under most waste distinction in the substantiality of
<br /> migrate from a waste matrix.Most management practices.Although the hazard posed by tri- and hexavalent `
<br /> trivalent chromium salts are virtually oxidation of trivalent chromium can chromium-containing wastes when 1I
<br /> insoluble.Trivalent chromium, occur on a theoretical basis(Carlin, disposed on land.
<br /> moreover,is strongly adsorbed by clays IM;U.S.EPA,19771,oxidation is Different considerations underly the
<br /> and by organic soil materials(U.S.EPA, unlikely to occur in normal land Agency's other programs.For example,
<br /> 1978. Bartlett, 1978;and Griffin.1979), disposal situations.Thus,oxidation does
<br /> decreasing the possibility of exposure not take place except under alkaline and 'Ultraviolet light-sensitized oxidation or trivalenl
<br /> via a groundwater exposure pathway aerobic conditions(Robertson,1975). chromium has been demonslraled under laboratory
<br /> even if migration occurs.In contrast. Even then.the rate of oxidation is very condiiona(Stephens,19.7),This oxidation did not
<br /> slow unless manganese dioxide is take place,however,when lake water was tested.
<br /> In any case,we do not believe that these
<br /> -Various aquatic species likowise are more present(Schroeder and Lee.1975).These experimental conditions refte.;t those normally
<br /> su1 ceptible to the hexavulenl form of chromium. conditions are not ordinarily found in occurring In a waste disposal environment.
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