<unk>  finds its major application in the production of PVC. It is volatile, so the primary exposure is via inhalation as against food or water with occupational hazards being highest. Prior to 1974, workers were commonly exposed to 1,000 ppm<unk> , causing<unk>  illness" such as acroosteolysis and Raynaud's Phenomenon. The symptoms of<unk>  exposure are classified by ppm levels in ambient air with 4,000 ppm having a threshold effect. The intensity of symptoms varies from acute (1,000–8,000 ppm), including dizziness, nausea, visual disturbances, headache, and ataxia, to chronic (above 12,000 ppm), including narcotic effect, cardiac arrhythmias, and fatal respiratory failure. RADS (Reactive Airway Dysfunction Syndrome) may be caused by acute exposure to<unk> .<unk>  is a mutagen having clastogenic effects which affect lymphocyte chromosomal structure.<unk>  is a Group 1 human carcinogen posing elevated risks of rare angiosarcoma, brain and lung tumors, and malignant haematopoeitic lymphatic tumors. Chronic exposure leads to common forms of respiratory failure (emphysema, pulmonary fibrosis) and focused hepatotoxicity (hepatomegaly, hepatic fibrosis). Continuous exposure can cause CNS depression including euphoria and disorientation. Decreased male libido, spontaneous abortion, and birth defects are known major reproductive defects associated with<unk> .<unk>  can have acute dermal and ocular effects. Dermal exposure effects are thickening of skin, edema, decreased elasticity, local frostbites, blistering, and irritation. The complete loss of skin elasticity expresses itself in Raynaud’s Phenomenon. The US OSHA limits<unk>  exposure of workers to no more than 1 ppm for eight hours or 5 ppm for 15 minutes. The US EPA and FDA limit<unk>  in drinking water to 0.002 ppm. Food (ingestion) is a trivial source of exposure. Liver toxicity The hepatotoxicity of<unk>  has long been established since the 1930s when the PVC industry was just in its infant stages. In the very first study about the dangers of<unk> , published by Patty in 1930, it was disclosed that exposure of test animals to just a single short-term high dose of<unk>  caused liver damage. In 1949, a Russian publication discussed the finding that<unk>  caused liver injury among workers. In 1954, B.F. Goodrich Chemical stated that<unk>  caused liver injury upon short-term exposures. Almost nothing was known about its long-term effects. They also recommended long-term animal toxicology studies. The study noted that if a chemical did justify the cost of testing, and its ill-effects on workers and the public were known, the chemical should not be made. In 1963, research paid for in part by Allied Chemical found liver damage in test animals from exposures below 500 parts per million (ppm). Also in 1963, a Romanian researcher published findings of liver disease in<unk>  workers. In 1968, Mutchler and Kramer, two Dow researchers, reported their finding that exposures as low as 300 ppm caused liver damage in<unk>  workers thus confirming earlier animal data in humans. In a 1969 presentation given in Japan, P. L. Viola, a European researcher working for the European<unk>  industry, indicated, "every monomer used in V.C. manufacture is hazardous....various changes were found in bone and liver. Particularly, much more attention should be drawn to liver changes. The findings in rats at the concentration of 4 to 10 ppm are shown in pictures." In light of the finding of liver damage in rats from just 4–10 ppm of<unk>  exposure, Viola added that he "should like some precautions to be taken in the manufacturing plants polymerizing<unk> , such as a reduction of the threshold limit value of monomer …" Cancerous tumors In 1970, Viola reported that test animals exposed to 30,000 ppm of<unk>  developed cancerous tumors. Viola began his research looking for the cause of liver and bone injuries found in<unk>  workers. Viola's findings in 1970 were a "red flag" to B.F. Goodrich and the industry. In 1972, Maltoni, another Italian researcher for the European<unk>  industry, found liver tumors (including angiosarcoma) from<unk>  exposures as low as 250 ppm for four hours a day. In the late 1960s, the cancers that all of these studies warned of finally manifested themselves in workers. John Creech from B.F. Goodrich discovered angiosarcoma (a very rare cancer) in the liver of a worker at the B.F. Goodrich plant in Louisville, Kentucky. Then, finally, on January 23, 1974, B.F. Goodrich informed the government and issued a press release stating that it was "investigating whether the cancer deaths of three employees in the polyvinyl<unk>  operations at its Louisville, Ky. plant were related to occupational causes." In 1997 the U.S. Centers for Disease Control and Prevention (CDC) concluded that the development and acceptance by the PVC industry of a closed loop polymerization process in the late 1970s "almost completely eliminated worker exposures" and that "new cases of hepatic angiosarcoma in<unk>  polymerization workers have been virtually eliminated." The Houston Chronicle claimed in 1998 that the<unk>  industry manipulated<unk>  studies to avoid liability for worker exposure and hid extensive and severe chemical spills in local communities. Environment pollution According to the United States Environmental Protection Agency (EPA),<unk>  emissions from polyvinyl<unk>  (PVC), ethylene dichloride (EDC), and<unk>  monomer <unk> M) plants cause or contribute to air pollution that may reasonably be anticipated to result in an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness.<unk>  is a known human carcinogen that causes a rare cancer of the liver." EPA's 2001 updated Toxicological Profile and Summary Health Assessment for<unk> M in its Integrated Risk Information System (IRIS) database lowers EPA's previous risk factor estimate by a factor of 20 and concludes that "because of the consistent evidence for liver cancer in all the studies...and the weaker association for other sites, it is concluded that the liver is the most sensitive site, and protection against liver cancer will protect against possible cancer induction in other tissues." Additional references * International Programme on Chemical Safety (IPCS) (1997). '"Vinyl<unk> . Poisons Information Monograph. PIM 558. WHO. Geneva. * National Poisons Information Service (NPIS) (2004).<unk> ." TOXBASE®. * World Health Organisation (WHO) (2000). "Air quality guidelines for Europe." WHO Regional Publications, European Series, No. 91. 2nd edition. WHO Regional Office for Europe. Copenhagen. * Hathaway G.J. and Proctor N.H. (2004). Chemical Hazards of the Workplace. 5th edition. John Wiley & Sons, New Jersey. * Risk Assessment Information System (RAIS) (1993). "Toxicity summary for<unk> . "Chemical Hazard Evaluation and Communication Group, Biomedical and Environmental Information Analysis Section, Health and Safety Research Division.
Vinyl chloride
Triphenylchloroethylene
Coal tar
Heptachlor
Hydrogen fluoride
Triphenylbromoethylene
Naphthalene
Butylated hydroxytoluene