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R&S 108740 BIO-MEDICAL RESEARCH " DOCUMENT DESCRIPTION FORM 63 68 69 76 Duplicate in all cards:-- year as-1961- Filnenj nvum>_/ b/'e9yr ) [Right justify [Numeric only] Author(s), as Last Name FS (No Punctuation) and coden for journal as JAMA preceeded by one blank space 1 ,, / _~-r s/j 20 2140 / / Ai 4160 77______ 78 Sub-Index Code 61 62 Title of Report; end with space-hyphen-hyphen-space. Follow with Index Terms, separated from each other with comma-space. Avoid other punctuation; do not abbreviate. rn ^ A/A ?;/, ,r// ''-'V.C' 21 22 23 24 Source (Journal, Vol., Number, Pages, Date ) 12 r /' /:-/ a ' 61 62 31 32_ Brief Summary 61 62 61 62 63 64 ~ - -.-V [**- MJJ ri R&S 108741 Environmental Health Perspectives Vol, IT, pp. SS-CJ, 197C ChemistryandToxicityof RameRetardantsfor Plastics by R. Liepins* and E. M. Pearce-^ An overview of commercially used flame retardants is given. The most used flame retardants are illustrated and the seven major markets, which use 96% of all flameretarded polymers, are described. Annual flame retardant growth rate for each major market is also projected. Toxicity data are reviewed on only those compositions that are considered commercially significant today. This includes IS compounds or families of compounds and four inherently flame-retarded polymers. Toxicological studies of flame retardants for most synthetic materials are of recent origin and only a few of the com pounds have been evaluated in any great detail. Considerable toxicological problems may exist in the manufacturing of some flame retardants, their by-products, and pos sible decomposition products. Introduction Practically all commercial plastics are "compou-nded" with various additives to improve their processing and end-use performance. In the order of total volume of additives used in 1974, flame retardants occupied second place after plasticizers with a volume of 384 million pounds (see Table 1) (1), Table 1. Additives in plastics. Plasticizers Flame retardants Colorants Heat stabilizers Lubricants Antioxidants Organic peroxides Blowing agents Antistats Ultraviolet stabilizers Amounts X 10"c, lb 1,650 384 311 92 67 30 26 14 4 4 ' Polymer Research Laboratory, Chemistry and Life Sciences Division. Research Triangle Institute, Re search Triangle Park. K. C. 27709. t Chemistry and Chemical Engineering Departments, Pol.t technic Institute of New York, Brooklyn, New York 11201. Types of Flame Retardants The major basic chemical elements in most commercial flame retardants are chlorine, phos phorus, and bromine. Most flame retardants contain one or more of these elements, often in addition to such other elements as nitrogen and antimony. The presence of nitrogen and/or antimony enhances the effectiveness of the basic elements in certain combinations (formu lations). Chlorine-Containing Flame Retardants. Chlorine-containing flame retardants are of three chemical types: aliphatic, cycloaliphatic, and aromatic (2). Chlorinated paraffins are by far the most widely used aliphatic chlorinecontaining flame retardants. These low cost products are offered in a broad range of chlo rine content and physical properties. Cyclo aliphatic chlorine-containing flame retardants are best represented by Diels-Alder adducts of hexachlorocyclopentadiene. The best known ex ample in this class is chlorendic anhydride (I). C! 0U c \ 0 / cII 0 I October R&S 108742 This flame retardant is used as an interme diate in the production of flame-retarded epoxy resins and unsaturated polyesters. Of the various aromatic chlorocompounds, :he best known commercial flame retardants are tetrachlorophthalic anhydride, chlorinated napthalenes, and tetrachlorobisphenol A (II). Phosphorus-Containing Flame Retardants. The best known commercial phosphorus-con taining flame retardants are phosphate esters: tricresyl phosphate, cresyl diphenyl phosphate, triphenyl phosphate, tris (isopropylphenyl) phosphate, and tris (2-ethylhexyl) phosphate (2). Bromine-Containing Flame Retardants. Bromine-containing flame retardants can be divided into four major types: aliphatic, cyclo aliphatic, aromatic, and ionic (2). In general, bromine-containing flame retardants represent the most diverse chemical structural types of all flame retardants. Some better know exam ples of aliphatic bromine-containing flame re tardants are: poly (vinyl bromide), 2,3-dibromopropanol, dibromoneopentyl glycol, tribromoneopentyl alcohol, and dibromobutenediol. An example of cycloaliphatic bromine-con taining flame retardants used commercially is hexabromocyclododecane. More examples of this type of flame retardants are used; how ever, they are proprietary compounds and their structures are not known. The most widely used aromatic bromine flame retardant is decabromodiphenyl ether. Other well-known examples are hexabromobenzene, hexabromobiphenyl, decabromobiphenyl, and tetrabromophthalic anhydride. A flame retardant containing both aliphatic and aromatic bromine is bis (3,3-dibromopropyl ether) of tetrabromobisphenol A (III). This flame retardant has generated significant commercial interest in Europe for use in poly olefins. Flame retardants containing ionic bromine include ammonium bromide and various phosphonium bromides. In addition to the above types, flame re tardants containing chlorine and phosphorus or bromine and phosphorus are prevalent and seem to become more important as time goes by. Commercially used examples of chlorineand phosphorus-containing flame retardants are tris (2,3-dichloropropyl) phosphate, tris(2-chloroethyl) phosphate, chlorinated polyphosphates, and bis(2-chloroethyl) vinyl phosphonate. One of the most widely used bromine- and phos phorus-containing flame retardants is tris (2,3dibromopropyl) phosphate. It is used in fibers, foams, and certain thermoplastics. Some other examples are tris (4-bromophenyl)phosphate, tris (2,4,6-tribromophenyl) phosphate, and di ethyl 2-bromoethyI phosphonate. Flame retardants containing bromine and chlorine (for example, vinylidene chlorobromide) and bromine, chlorine, and phosphorus, for example, tris(bromochloroisopropyl) phos phate, are known but essentially not used. Usage of Flame Retardants The major markets for plastics can be di vided into seven categories (see Table 2) (3). These seven categories accounted for 72 (7 of all plastics used and 96(7 of fire-retardant polymers (4)- Of the total consumption of 24.4 billion pounds of plastics in 1973, only a little more than 6(7 constituted fire-retarded poly mers- The largest volume end-use for fire-retarded polymers was in building and construction. Of the total of 5.2 billion pounds of plastics con sumed, about 10(7 or 515 million pounds was classified as fire-retarded. Fire-retarded plastic growth in this segment is expected to be 1315(7 per year (4). The second largest volume end use was in the electrical and electronics industries. Fireretarded plastics consumption amounted to 369 1 56 Environmental Health Perspectives w? &X31 aiaw- ***r2iU Table 2. Major markets for plastics--1973. Building and construction Electrical/electronic Transportation Furnishings Packaging Housewares Appliances Other Plastics X 10-, lb 5,154 1,633 1,551 1,095 5,830 1,3631 938 J 6,831 FR plastics X 10-e, lb 515.4 386.6 310.2 164.3 58.3 `-- -- _ 23-46 68 FR plastics % 10.0 22.5 20.0 15.0 1.0 1-2 1 million pounds out of 1.6 billion pounds. Fireretarded plastics growth is expected to be in the range of 10-12% per year range (4). Transportation was the third largest market for fire-retarded plastics, using about 310 mil lion pounds out of 1.6 billion pounds. This 'market is expected to show a major growth, as more plastics are used to produce smaller and lighter cars. Fire-retarded plastics will grow at about 17% per year in this market (4). . The next major market is in furnishings, consuming about 164 million pounds of fireretarded plastics out of 1-1 billion pounds. Here too, a very high rate of growth (17-20%) is expected as a result of the proposed Con sumer Product Safety Commission standard for upholstered furniture. Although packaging was the largest market for plastics, only about 5S million pounds (1%) out of 5.S billion pounds were flame-retarded. Generally, fire-retarded plastics are not re quired in this application. Finally, housewares and appliances used about 2.3 billion pounds of plastics, of which only 23 to 46 million pounds (1-2%) were flame-retarded. In summary, much activity is expected in this area as a result of tighter construction codes and stiffer government requirements for flame and smoke suppression. Better flame re sistance is an increasingly pervasive legal re quirement and is the prime reason for the projected overall annual growth rate of 1517% for flame retardants. Toxicity of Flame Retardants Broadly speaking, all flame retardants can be subdivided into "nonreactive" and "reactive" types. Nonreactive types are used as is prior to or during polymer processing and as a finish or surface coating. Pveactive flame retardants are used as comonomers in the polymerization or grafting of the material. This leads to an important distinction as concerns the toxicity of a material when used as a flame retardant. Thus, materials to be used as nonreactive flame retardants have to be inherently , nontoxic, whereas reactive flame retardants which are converted into nontoxic polymeric materials may not necessarily have to be nontoxic (vinyl chloride is an example). Of course, effective removal of traces of unreacted toxic reactive flame retardants is a problem when dealing with such materials. Toxicological studies of flame retardants for most synthetic materials are of a rather recent origin--since late 1960's. Thus, still only a few detailed toxicological studies on flame re tardants have been published. Overall we have found no evidence for persistent toxic concern from the flame retardants themselves. There is a more serious toxicological problem in the manufacturing of some flame retardants, their by-products, and possible products of degen eration. However, these problems are outside the scope of this report. Review of Experimental Studies Only those compositions considered commer cially significant today are reviewed. Thus, we find data on 18 compounds and/or families of compounds that are pertinent. Some data on inherently flame retarded polymers are also included. The flame retardants are subdivided into the following groups: nonreactive flame 3) </> CO -4 CO r: fa si t. October 1976 o( retardants, including also plasticizers which function also as flame retardants; reactive flame retardants; inorganic-nondurable flame retardants; and inherently flame-retarded poly mers. Nonreactive Flame Retardants Dccabromodiphenyl Oxide. A 2-yr toxicity study with decabromodiphenyl oxide, DBDPO (d-9) was conducted. Rats ingesting 1.0, 0.1, or 0.01 mg DBDPO/kg for 2 yr showed no dis cernible alterations in body weight, food con sumption, hemotology, organ weights, tumor formation, or tissues subjected to pathologic examination. Serum, muscle, and kidney showed no increase in bromine content. In liver, showed less weight gain and a decrease in organ weight. However, no clinical or histopathological effects were noted. Tissue residue analysis showed bromine build-up in all tissues at the end of the 28-day feed period. After 6 weeks withdrawal, residue levels decreased to essentially control levels. It is concluded that TRIS exhibits very low oral and dermal tox icity, is not a skin or eye irritant, and has a low order of subacute toxicity as determined by 28-day rat-feeding studies. A recent study (11), however, showed that 1 ppm of TRIS in water for 5, days killed goldfish (Carassiu-s auratus). Hexabromobenzene (IV) (12). Administra tion of hexabromobenzene to mice orally in doses from 0.875 to 7.0 g/kg-day for 30 days Br Br R&S 108744 DBDPO low-level steady-state conditions were attained by 12 months. Adipose tissue showed a timeand dose-related increase in bromine content subsequent to ingestion of 1.0 or 0.1 mg DBDPO/kg-day. Despite the accumulation of bromine in adipose tissue, no discernible toxi cologic effects were observed. DBDPO is neither an eye nor skin irritant nor skin sensi tizer, nor is it absorbed through the skin in acutely toxic amounts: it does not possess bromacnegenic activity. Tris(2,3-dibromopropyl) phosphate (TRIS). Acute oral LD;o for TRIS (10) in male albino rats was calculated to be 5.24 g/kg. Acute der mal LD-,,, of TRIS for male and female New' Zealand white rabbits was found to be greater than 8.00 g/kg. TRIS was found not to be an eye or skin irritant in rabbits. Repeated skin patch tests on 52 human subjects showed that TRIS did not produce primary skin irritation, (CH1CHCH1O), PO II Br Br TP.IS skin fatigue, or skin sensitization. Rats fed 100 ppm and 1000 ppm TRIS for 28 days Br Br IV had no effect on food consumption, body weight, blood serum enzymes and did not induce patho logical changes in the organs examined. - Chlorinated Paraffins. Subacute toxicity tests in which as much as 1 g of chlorinated paraffin (V) per day was fed to rats for 42 days (13) produced no noticeable effects. Con- Cl H-- f(CHJ . (CH), (0,1--H II. Cl Cl V tact of the skin with chlorinated paraffins does not give rise to any irritation or sensitization. Antimony Trioxide. Subacute oral toxicity for antimony trioxide (Sb,Ou) administered in the food to rats for 30 days produced the following dose-symptoms relationships (14) : maximum dosage having no effect, 0.27 g/kg; reduced growth, reduced appetite, micropath ology in liver, kidney, spleen, or testis of any rat at 1.07 g 'kg. Single dose, oral LD-3 is higher than 20 g/kg. 5S Environmental Health Perspectives Plasticizers That Also Function as Flame Retardants Plasticizers are mixed into polymers to in crease flexibility and workability. The esters formed by reaction of the three functional groups of phosphoric acid with alcohols or phenols are excellent plasticizers. The phos phoric acid esters are also remarkable flameretarding agents, and for this reason are ex tensively used in plastics. Generally, phosphoric acid esters are toxic {13). Tricresyl phosphates have been one of the most important plasti cizers, and it is believed that the tricresyl phos phate used as a plasticized is free of the ortho isomer. 1 g/kg body weight are fatal to rats. Oral doses up to 4 g/kg have been tolerated {13,16). The material possesses moderate skin irritant action in rabbit and man. 2-Ethylhexyl Diphenyl Phosphate (Santicizer 141). Rats were kept for at least 2 yrs on diets containing 5.0, 1.0, 0.125, and 0.0625 ft ethylhexyldiphenyl phosphate (VIII). The diets containing 0.125 and 0.0625 (T of the phosphate had no adverse effects {13, 17). Dogs were fed on diets containing 2.5 and 1.5 (Tc of the phosphate for 6 days a week over 2 years. OH, I . I VIII Dogs experienced normal weight gain, and cr-Tricresvl phosphate nothing in particular was found at macro scopic or microscopic post-mortem examina The ortho isomer has prominent neurotoxic properties. The question of the purity of ma terials in this group because of the neurotoxic components is a very serious one. Triphenyl Phosphate. Repeated ingestion by rabbits of doses of triphenvl phosphate (VI) varying between 0.10 g and 1 g/kg body weight gave rise to kidney damage {13, 15) which, tions. In rabbits single doses up to 24 g/kg have not caused death. To sum up, the sub stance has a low toxicity and its use in contact with food has been authorized by the Food and Drug Administration. Tricresyl Phosphate. Tricresyl phosphate (IX) is claimed to be the most toxic of all plasticizers in general use {13). In rabbits, a single dose of 0.10 g/kg is fatal; in dogs the t ? dose is 0.50 g/kg {13, 15). In white mice, a I single dose of 12 mg/g is fatal when injected )--0 PO subcutaneously. The minimum toxic dose for human beings has not been stated precisely. In general, it is very low, and traces are enough 33 I VI OJ however, cleared up. Intraperitoneal injections of 0.1-0.2 g/kg do not have any toxic effect. Subcutaneous injection of 1 g/kg was fatal to rabbits. Cresyl Diphenyl Phosphate. Intraperitoneal doses of cresyl diphenyl phosphate (VII) over VII PO CH, IX to cause paralysis of the extremities of the limbs. Of the three positional isomers, the meta isomer is less toxic and the para isomer is very slightly toxic. Of the mono-, di-, or tri-o-cresyl esters, the monoester in animals was six times more toxic than the tri-o-cresyl ester. Tri-2-elhylhexyl Phosphate. Tri-2-ethylhexyl phosphate (X) has only -a very slight ooNol CJ1 October 1976 59 i, J R&S 108746 acute toxicity; for rats the lethal dose LDi0 is 39.S g kg. Subacute oral toxicity for the (CH;CH:CH:CH:CHCH;0)3PO CHj I CH, X phosphate given in the food to rats for 30 days produced the following dose-symptoms relationship; maximum dose having no effect, 0.43 g/'kg, reduced growth at 1.55 g/kg. Reactive Flame Retardants Vinyl Chloride. There is probably more toxicological information now on vinyl chloride (A7) than any other monomer {13, 18-22). For example, a recent paper on health effects of vinyl chloride monomer contains an anno tated bibliography of some 162 references {19). The monomer, but not the polymer, is toxic and is a carcinogen. When rats were exposed CH: = CHC1 XI to 50 to 10,000 ppm of atmospheric concentra tions of vinyl chloride, 4 hr/day, 5 days/week for 12 months, angiosarcomas, symbal gland carcinomas, and nephroblastomas were devel oped. The upper exposure limit of 1 ppm aver aged over an 8-hr period has been set by the Occupational Safety and Health Administra tion of the Department of Labor. Vinylidene Chloride. Exposure of rats to 500 ppm of vinylidene chloride (XII) for 6 hrs caused nose irritation, retarded weight gain, and liver cell degeneration {13, 18, 23). CH: = CCl: XII For a 4-hr exposure, the lethal dose LDS0 for rats was found to be of the order of 32,000 ppm. 2,2',6,6' - Tel rabromo-3,3',5,5' -tetraniethy1-4,4'dihydroxybiphcnyl (TTDB). Acute toxicity studies in rabbits and rats showed that TTDB (XIII) is a possible eye irritant. ( is not a pri mary skin irritant, and is not a toxic material by the dermal route of administration and by the oral route of administration {21). A lethal dose of LD;() of 5 g/kg was observed. In a 2S-day chronic toxicity studies, rats were fed TTDB at dosage levels of 1, 10, 100, and CH: Br Br CH: CH: Br Br XIII CH, 1000 ppm- No changes considered to be re lated to TTDB were seen in behavior, appear ance, body weight, food consumption, gross or microscopic pathologic lesions, or organ weight variations. N-Methylol dimethylphosphonopropionamide (Pyrovotex FR), Pyrovatex (XIV) shows OO tr (CHjO):PCH:CH.CNHCH:OH XIV only a very slight acute toxicity when admin istered orally to rats {25). A lethal dose LDi0 of 6 g/kg was observed. It produces no per ceptible signs of skin irritation. Tetrakis(hydroxymethyl)phosphonium ' ' chloride and Hydroxide. THPC1 (XV), (HOCH:): P+ ClXV (HOCH:).P'OH- XVI THPOH (XVI), and Pyrovatex FR are prac tically the only flame retardants currently used for cotton textiles {2G). THPC1 is a watersoluble compound prepared from formalde hyde, phosphine, and hydrogen chloride. The CHiO + HCP+PHj ;= (HOCH:). P* CV THPC1, THPOH flame-retardant system is an extremely versatile one as can be seen from some of the variations used: THPC1 -f- methylolmelamine + urea; THPC1 -f- niethylolmelamine -f- urea -f- NH,; THPC1 4- NaOH -J- NH^; 60 Environmental Health Perspectives * .i.1.'*-...1.1 li 1 i ii'Mi--jijgi R&S 108747 THPC1 -f NaOH 4- NH, + amide; THPC1 + NaOH -I- methylomelamine + urea; THPC1 + NaOH 4- methylolmelamine 4- urea 4- copper salt. The final flame-retardant composition on the fabric can. be broadly characterized as a highly crosslinked, aminated, phosphine oxide one. The THPC1 reacts with the amine groups in the system, and following hydrolysis loses chlorine, resulting in the general composition XVII. when used in a polyurethane foam formulation during the combustion of the foam decomposes and is known to be {31, 32) responsible in part for the generation of an extremely toxic com bustion product, 4-ethyl-l-phospha-2,6,7-trioxabicyclo[2.2.2]octane-1 oxide (XIX). This ap parently can occur when polyols based on other than trimethyol propane are also used. (RNHCH:)3PO XVII During the curing of the composition on the fabric, HC1 and formaldehyde are gen erated. To eliminate the problem of HC1 gen eration, sodium hydroxide can be used in the formulation. Heat and moisture have been shown to degrade the THPC1 or THPOH fin ishes. It has been shown experimentally that detectable amounts of formaldehyde, hydrogen chloride, and phosphine are given off for as long as 2 months after the finishing opera tion {27, 28). The danger here is that suf ficient amounts of formaldehyde and hydrogen chloride could conceivably be given off to gen erate spontaneously small amount of bis(chloromethyl) ether {29). 2HC1+2CH-.0 ^ ClCH:0CH;Cl-f-H:0 In the study by Afanazeva et ah {27), it was shown that six THPC1 formulations pro duced local irritant and systemic effects. Topi cal applications of aqueous extracts resulted in death of up to 70 {7c of the experimental mice. However, the dosages used were not given and the presence of bis(chloromethyl) ether was not demonstrated. Recently it was shown that 1 ppm of THPOH in water for 5 days was toxic to goldfish {Carassius auratus) {11). Furthermore, THPC1 was found to be one of the most intense skin irritants tested {30). 0,0-Dieihyl-'N.'S-bis (2-hydroxyethyl) arninomcthyl Phosphonate. 0,0-Diethyl-Ar,Ar-bis (2- 0 T (CH:CHjO): P-CH;N (CH:CH:OH), XVIII hydroxyethyl) aminomethyl phosphonate (XVII) is presumably a nontoxic flame retardant, but XIX The reported LD5() for XIX, when admin istered interperitoneally to mice, is 1 mg/kg {33). This represents a relative toxicity level of approximately six times that for diisopropylfluorophosphate (a chemical warfare agent) or parathion (an insecticide). Inorganic Nondurable Flame Retardants The use of nondurable flame retardants has been declining since about late 1950's and their usage in plastics has been minor. The major markets are in paper.and wood products and forest fire fighting. Some of the more common formulations consist of the following: borax/ boric acid mixtures, Na:B40; lOH-O/HjBCh; ammonium sulfamate, NH^SONH,; diammo nium phosphate, (NH,):HPO,; ammonium bromide, NH,Br. The borax/boric acid compo sitions appear to be the least toxic of all the nondurables. Ammonium sulfamate is sold also as a weed killer and reportedly has an oral LD 50 in rats of 3.9 g/kg. Ammonium phos phates can cause skin irritation; however, one of their long-term usages has been in ferti lizers. Ammonium bromide is a sedative at oral doses of 0.6-2 g. Inherently Flame-Retarded Polymers In general, most synthetic high ploymers are chemically inert and exhibit only slight or no physiological and toxicological effects. How ever, there are distinct differences in their action depending upon the mode of their intro duction into the body. October 1976 61 !,yi_ ! 1 9 "n i If" JI 'uyIIJ TLh Some of the polymers with inherent fiameretardant properties which have been investi gated for their toxicological properties are: poly (vinyl chloride), vinyl chloride'vinylidene 3. Anonymous, Goodbye resin shortage? Don't you be lieve it! Mod. Plastics, 52: 44 (Jan. 1975). 4. Schongar, L. H., and Zengierski, L. A. Flame Re tardant Polymer Markets. Hooker Chemicals and Plastics Corp., Niagara Falls, N. Y. (1975). chloride copolymer, polytetrafluoroethylene, and 5. Norris, et al. J. M. Toxicological and environmental chlorinated rubber. Poly (vinyl chloride) tubes as a prosthetic material for replacing the esophagus of a dog gave rise to no irritation and were very well tol factors involved in the selection of decabromediphenyl oxide as a fire retardant chemical. J. Fire Flammability/Combustion Toxicol. 1: 52 (1974). 6. Kociba, R. J., et al. Results of a two year dietan feeding study with decabromediphenyl oxide erated by the animal (34). Vinyl chloride/vinylidene chloride copolymer has been incorporated (590 in a daily diet for dogs and rats (35). The dogs were main (DBDPO) in rats. J. Fire and Flammability/ Combustion Toxicol., 2: 267 (1975). 7. Norris, J. M., et al. Toxicology of octabromobiphenvl and decabromodiphenyl oxide. Environ. Health. Perspect. 11: 153 (1975). tained on the diet for 1 year and the rats for 2 years, and no signs of poisoning were found in these animalsPolytetrafluoroethylene has been evaluated in rats. Feeding a diet containing 25c/c of finely powdered polytetrafluoroethylene induced no symptoms of poisoning (36). Subacute oral toxicity tests on rats with "chlorinated rubber" indicated the material to 8. Norris, J. M., Norris, et al. Toxicological evalua tion of fire retardant chemicals; decabromodiphenyl oxide and octabromobiphenyl, Paper presented at Fall Meeting, Am. Soc. Pharmacol. Exp. Therap. 1973; The Pharmacologist, 15: 394 (1973). 9. Norris, J. M., et al. Toxicological and environ mental factors involved in the selection of decabro modiphenyl oxide as a fire retardant chemical. In: Polymeric Materials for Unusual Service Condi tions (J. Appl. Polym. Sci. Symp., 22) M.A. Golub and J. A. Parker, Eds., Wiley-Interscience, New be as innocuous as the chlorinated paraffins were (13). York, 1973, p. 195. 10. Kerst, A. F. Toxicology of tris(2,3-dibromophenyl) phosphate. J. Fire Flammability/Fire Retardant Chem. 1: 205 (Nov. 1974). Conclusion 11. Gutenmann, W. H., and Lisk, D. J. Flame retardant release from fabrics during laundering and their In general, flame retardants per se present less problems than the components from which they are manufactured, by-products in their manufacture, and products of their degrada tion. More studies on their toxicity and of the toxicity to fish. Bull. Environ. Contamination Toxi col. 14: No. 1, 61 (1975). 12. Kitagawa, H., Satoh, T., and Fukuda, Y. Subacute toxicities of hexabromobenzene. Oyo Yakuri, 9: 663 (1975). 13. Lefaux, R., Practical Toxicology of Plastics, CRC decomposition products of flame retardants Press, Cleveland, Ohio, 1968, pp. 140, 370. when they reside in the polymer substrates are 14. Smith, H. F., Jr., and Carpenter, C. P. Further badly needed. experiences with the range finding test in the in Co Another emerging area that needs more at- dustrial toxicology laboratory. J. Ind. Hyg. Toxicol. 30: 63 (1948). 2 tention is the area of multiple-functional addi- 15. Guess, W. L,, and Haberman, S. Toxicity profiles 00 tives. The matter of combining in a single of vinyl and polyolefinic plastics and their additives. product the additive functions that formerly J. Biomed. Mater. Res. 2: 313 (1968). required two or three or more separate ma 16. Mallett, F. S., and VonHaam, E. Studies on the terials is a cost-efficient trend that will become more important. We already are familiar with one such group of materials, the phosphate plasticizer-flame retardant materials. Inciden tally, this group of materials, because of the toxicity and skin effects of compounds used of the rubber and plastics industry. Part II. Arch. Ind. Hyg. Occup. Med., 6:231 (1952). 17. Halpern, L. K., and Weiss, R. S. Toxicity of 2-ethvlhexyl diphenvl phosphate. Arch. Ind. Hyg. Occup. -Med., 8: 284' (1953). possibility of the presence of neurotoxic com 18. Jaeger, R, J. et al. Biochemical toxicity of unsat- ponents, needs a lot more toxicological evalua tion work than appears to be available, uratod halogenated monomers. Environ. Health Perspect. 11: 121 (1975). 19. Warren, H., ami Huff, J. E. Health effects of vinyl REFERENCES 1. Anonymous. For chemicals and additives, a new chloride monomer: an annotated literature collec tion, Environ. Health Perspect. 11: 251 (1975). splash in R & D. Mod. Plastics 52: No. 9, 41 (1975). 20. Hefner, R. E., Jr., Watnnabe, P. G., and Gehring, 2. Level;, R. P., and Williams, D. 0. Flame retardants. Modern Plastics Encvclopedia, 52: No. 10A, 200 (19751. P. J. Preliminary studios on the fate of inhaled vinyl chloride monomer (YCM) in rats<- Environ. Health Perspect. 11: 85 (1.075). R&S 62 Environmental Health Perspectives 21. Reynolds, E. S., Jaeger. R. J., ami Murphy, S. D. retardants on exposure to UY and elevated tem Acute liver injury by vinyl chloride: envelopment peratures. Text. Chemist Colorist 5: 55 (1973). of endoplasmic reticulum in phenobarbital-pre- 29. Kallos, G. J., and Solomon, R. A. Investigation of treated rats. Environ. Health Perspect. 11: 227 the formation of bis-chioromethyl ether in simu (1975). lated hydrogen chloride--formaldehyde atmospheric < 22. Drew, R. T., et al. Effects of vinyl chloride expo environments. Am. Ind, Hvgiene Assoc. J., 34: 469 1, sures to rats pretreated with phenobarbital. En (1973). viron. Health Perspect. 11: 235 (1975). 30. Aoyama, M. Effect of antiflame treating agents bn 23. Gage, J. C. The subacute inhalation toxicity of 109 the skin. Nagoya Med. J., 20: 11 (1975). j industrial chemicals. Brit. J. Ind. Med., 27: 1 31. Voorhees, K. J., et al. The identification of a highly \ (1970). --------------------------- toxic bicvclophosphate in the combustion products | ! 24. Orlando, C. M., and Thomas, D. P. A new aromatic of a fire-retarded urethane foam. J. Polym. Sci. j biominated flame retardant and its application in Polym. Letters Ed. 13: 293 (1975). 1 high impact polystyrene. J. Fire Flammability/Fire 32. Petajan, J. H., et al. Extreme toxicity from com Retardant Chem., 2: 1S3 (1975). 25. Aenishanslin, R., et al, A new chemical approach bustion products of a fire-retarded polyurethane foam. Science 1S7: 742 (1975). jJ to durable flame retardant cotton fabrics. Textile 33. Ballet, E. M., and Casida, J. E. Bicyclic phosphorus j Res. J. 39: 375 (1969). esters: high toxicity without cholinesterase inhibi- I 2G. Hindersinn. R. R., and Wagner, G. M. Fire re- tion. Science 1S2: 1135 (.1973). j tardancy. In: Encyclopedia of Polymer Science and 34. Chalnot, P., Benichoux, R., and Gille, P, Prothese Technology, W iley, New York, 1967. de 1'oesophage en matiere plastique. Presse Medi 27. Afanaseva, L. V., and Evseenko, N. S. Hygiene cate, 82: 1742 (Dec. 25. 1952). evaluation of fireproof textiles processed with an 35. Wilson, R. H., and McCormick, W. E. Toxicology of organophosphorus impregnant based on tetrnkis- plastics and rubber--plastomers and monomers. (hydroxymethylphosphonium chloride). Gig. Sani- Ind. Med. Surg., 23: 479 (1954). tar. 36: 450 (1971). 36. Zapp, J, A., Toxic and health effects of plastics and 28. Meczeno, L. W., et al. Degradation of selected flame resins. Arch. Environ. Health 4: 335 (1962). R&S 108749 October 1976 ro-;v4.;^: t.vt-fi-;.... W;v -w . *.................. .1 i ib 63 *. *i' _