Document 06zXKXjRMKxkYe0gBw9oy5gvV

Q 3. Flint umi or manufacture PCB's? A 3. first, it i* important to nota that PCS'* and PCB containing products wars navar manufactured at ths^H^^B plant sita. PCB's vara usad as an addsd safety pree^Mon in the Therminol Haat transfar systems, as was done in literally hundreds of such systems throughout the country. PCB's wars usad as a haat transfar fluid because they are fire resistant, vary stable and chemically inert compounds, as wall as being good haat transfar madia. PCB's ware (and are still today) used by countless industries from manufacturers to hospitals in applications requiring an extra flame resistant safety factor, as they were in every Therminol Heater unit until 1971 when we switched to a non-PCB heat transfer fluid. Q 5. What are PCB's? A 5. PCB's are compounds consisting of carbon, hydrogen and chlorine atoms. They are chemically inert, stable and fire resistant. These properties made them invaluable for their principal use -- as cooling and insulating fluids in heavy-duty electrical equipment, including capacitors and transformers. Q 6. For more than 40 years, the use of PCB electrical fluids was required in most high-rise buildings, schools, hospitals and industrial operations where the risks of fires or explosions were major concerns. What's the problem with PCB's? A 6. PCB's are very stable chemicals. Because they biodegrade very slowly, they are environmentally persistant compounds. They can bioaccumulata in the fatty tissue (adipose tissue) of fish and animals including humans. While their persistence and bioaccumulation constitutes a concern, their mere presence and durability, par se, does not make them dangerous or a threat to human health. MOWS 003953 In short term exposure/feeding tests, PCB's are not acutely toxic. They ere classified by AIHA (American Industrial Hygiene Assoc.) as "slightly toxic to practically non-toxic." Long tarn aninal tests, e.g., life tine feeding studies for rats have given equivocal and contradictory results. However, several retrospective human epidemiology studies of occupationally exposed workers have failed to find any statistically significant chronic hunan health effects,except skin disorders such as chloracne and dermatitis which are reversible upon removal from exposure. No cancer, cardiovascular or neurological illnesses were found at a statistically significant level. In all worker exposures, levels of exposure were very high for exceedingly long periods of time, as long as 20-40 years in many cases. q 7. What are phthalates? A 7. Phthalates are esters composed of phthalic anhydride and one or more of a number of alcohols. They are used in plasties to impart softness or flexibillity to plastics. Perhaps the easiest way to help you identify them is the "new car smell" you're familiar with is the plasticizer in the vinyl of the car. Q 8. What haalth/anvironmental problems do they cause? A 8. Phthalata esters readily biodegrade and do not accumulate. They are not generally harmful to aquatic life at concentrations below solubility in water. While phthalates are on the priority pollutant list, these are much less environmentally prevalent than EPA originally thought and much less toxic to aquatic organism than EPA erroneously thought. While there has bean some recent concerns about one phthalate and its affect on rodents at high doses, no evidence exiats on harm to humans even after the many years phthalates have been manufactured and used. MQNS 003954