1 **ATTACHMENT 5 Selected SNUR Case History Abstracts** 2 HEXACHLORONORBORNADIENE (CAS # 2432 - 99 - 7) also known as HEX - BCH. 6 TOXICITY

• Extremely persistent compound with a great tendency to bioaccumulate. • Slow biodegradation. Very toxic to fish. Possible analogue to known carcinogens. II. REFERRI

NG OFFICE’S CONCERNS/NEEDS

• Monitor: its manufacture, importation, and processing; intended end uses, and potential worker exposure and environmental releases. Once production levels reach a certain point, EPA will reconsider its decision not to text HEX - BCH. III. USES A. Past and Ongoing Commercial batch manufacture and processing. Intermediate in the production of isodrin which is an intermediate in the production of endrin (both pesticides). B. Sm all Business Capable of production by a small firm. IV . REGULATORY BACKGROUND

• Listed on the Preliminary Assessment Information Rule. (One - time reporting only). • Listed on the section 8(d) model health and safety data reporting rule (40 CFR Part 716). • Loc al limit on its discharge in a public treatment sy stem. Limit based on plant’s treatment capacity and not on human health or environmental risk. V. RECOMMENDATION/RATIONALE: Section 8(a) rule for ongoing uses and significant new use rule for non - ongoing u ses. Well documented high toxicity concern. Small businesses potential. Satisfies referring office’s needs. No federal regulation exists to provide a governmental entity with an opportunity

to evaluate potential human and environmental exposures to HEX - BCH from its manufacture, importation, processing, and intended end use; and to protect human beings and the environment from potentially adverse exposures before they occur.3 METHYL N - BUTYL KETONE (CAS # 591 - 78 - 6) also known as MBK. 7 TOXICITY • Causes central and peripheral neuropathy in humans. Nerve damage is irreversible at concentrations as low as 50 ppm. • Absorbed readil y through the skin. Eye and skin irritant. Limited evid ence suggests testicular atrophy . II. REFERRI

NG OFFICE’S CONCERNS/NEEDS

• Monitor: its resumption of commercial manufacture, importation, and processing; intended end uses, and potential worker and consumer exposure. III. USES A. Past Commercial manufacture, importation and processing. Solvent in lacquers, sealers, varnish removers, oils, fats, and waxes. (i.e., consumer products). B. Ongoing Importation for toxicological research and development. C. Small Business Capable of production by a small firm. IV . REGULATORY BACKGROUND

 Occupational Safety and Health Administration standard (8 hour Time Weighted Average (TWA) 100 ppm).  American Conference of Governmental Industrial Hygienists TWA 5 ppm. No binding effect.  National Institute of Occu pational Safety and Health TWA 5 ppm. No binding effect. V. RECOMMENDATION/RATIONALE: Significant new use rule. Well documented high toxicity concern. Small businesses potential. Satisfies referring office’s needs.4

No federal regulation exists to provide a governmental entity with an opportunity

to evaluate potential human and environmental exposures to MBK from its manufacture, importation, processing, and intended end use; and to protect human beings and the environment from potentially advers e exposures before they occur.5 URETHANE (CAS # 51 - 79 - 6) Urethane is a name commonly but improperl y applied to high molecular weight poly urethanes used as foams, elastomers, and coatings. These products are not made from the urethane, and do not generat e urethane upon decomposition. I. TOXICITY

• Urethane is well established as a carcinogen. Malignant tumors have occurred in many species of animals following the administration of urethane b y the oral, inhalation, topical, subcutaneous, an d intraperitoneal routes. Urethane is also a transplacental carcinogen that readil y traverses the placenta and affects the fetus. • Toxic fumes when heated; liver toxin; bone marrow depressant. II. REFERRI

NG OFFICE’S CONCERNS/NEEDS

• Monitor: its resumpti on of manufacture, importation, and processing; intended end uses, and potential worker and consumer exposure. III. USES A. Past Commercial manufacture, importation and processing. Intermediate in the production of N - hydrox ym eth yl derivatives, which are useful as cross - linking agents for imparting wash - and - wear properties to fabrics. Human medicine: sclerosing agent for varicose veins and hemorrhoids, anti - neoplastic agent, h ypnotic, treatment of chronic leukemia, and multiple myel oma. Pharmaceutical intermediate. B. Ongoing Toxicological research. C. Small Business Capable of production by a small firm. IV . REGULATORY BACKGROUND Banned b y the Food and Drug Administration as an active and inactive ingredient in drugs. FDA also prohibited the use of a food preservative that produces urethane when it is used tin acidic beverages. Designated b y EPA as a Toxic Hazardous Waste #238. • Listed as a Hazardous material under the Hazardous Materials Transportation Act.6

V. RECOMMENDATION/RATIONALE: Significant new use rule. Well documented high toxicity concern. Small businesses potential. Satisfies referring office’s needs. No federal regulation exists to provide a governmental entity with an opportunity

to evaluate potential human and environmental exposures from urethane’s manufacture, importation, processing, and intended end use; and to protect human beings and the environment from potentially adverse exposures before they occur. The consequences of not collec ting this information is to allow, without EPA review, human and environmental exposures to toxic chemical substances.7 PENTABROMOETHYLBENZENE (CAS # 85 - 22 - 3) also known as PEB. I. TOXICITY • Carcinogenicity observed in other structurall y related compoun ds having a poly halogenated aromatic moiety. • Persistent compound with a great tendency to bioaccumulate. Slow biodegradation. II. REFERRI

NG OFFICE’S CONCERNS/NEEDS

• Monitor: its resumption of commercial manufacture, importation, and processing; intended end uses, and potential worker exposure and environmental release. If production is to be reinstated, EPA will reconsider its decision not to test HEX - BCH. III. USES A. Past and Ongoing Has been used in the past as an additive - ty pe flame retardant. No known ongoing uses. B. Small Business Capable of production by a small firm. V. REGULATORY BACKGROUND The Interagency

Testing Committee designed PEB for priority consideration in its 15th report. Listed on the section 8 (d) model health and safety data reporting rule (40 CFR Part 716). • Listed on the Preliminary Assessment Information Rule. (40 CFR Part 712). • Proposed, pursuant to section 4(a)(1)(A) findings, that chemical fate and environmental effects testing be perform ed. • Proposed Test Rule withdrawn due to termination of all known manufacture and processing operations.8

V. RECOMMENDATION/RATIONALE: Significant new use rule. Structurally

analogous to substances of carcinogenic concern. Small businesses potential. Sati sfies referring office’s needs. No federal regulation exists to provide a governmental entity with an opportunity

to evaluate potential human and environmental exposures to PEB from its manufacture, importation, processing, and intended end use; and to pro tect human beings and the environment from potentially adverse exposures before they occur.