Chlorine skin absorption

Because of the nature of some applications in which chlorinated paraffins are used, skin contact is inevitable and therefore an important potential route into the body. Skin absorption studies (7) have shown that chlorinated paraffins are very poorly absorbed through the skin and should not cause significant systemic concentrations. 

Exposure of workers by inhalation or skin absorption to lower-chlorinated naphthalenes (penta- and hexachloro) causes a severe acne-form dermatitis, chloracne. Surprisingly, on human volunteers, octachloronaphthalene was entirely nonacneigenic. Octachloronaphthalene (20 mg, 5 times/week for 2 weeks) did not induce gross or histologic changes in skin of hairless mice." ... 

Carbon tetrachloride is colorless, heavy, non-flammable liquid with a characteristic odor. It has a boiling point of 78 Celsius, and a melting point of -23 Celsius. Carbon tetrachloride is insoluble in water, but miscible with alcohol, benzene, chloroform, ether, and carbon disulfide. Carbon tetrachloride is a potential poison, and inhalation, ingestion, and skin absorption should be avoided at all cost. Carbon tetrachloride may be a carcinogen. It is prepared on an industrial scale by the chlorination of methane, but can be conveniently prepared by reacting chlorine with carbon disulfide in the presence of iron fillings the carbon tetrachloride is recovered by distillation. 

Hazard An animal carcinogen. Toxic by ingestion, inhalation, and skin absorption strong irritant. TLV (54% chlorine) 0.5 mg/m3 (42% chlorine) 1 mg/m3. 

Properties Colorless, mobile liquid becomes yellowish under the action of light and air. Fruitlike odor (high dilution). Decomposed by water. Attacks brass but not iron (dry). D 1.742 (14C), bp 156C (decomposes), fp —65C, coefficient of thermal expansion 0.0011, vap d 6 (air = 1.29), volatility 20,000mg/m3(20C), vap press 2.29 mm Hg (21.5C). Soluble in alcohol, benzene, ether, and water. Derivation Chlorination of ethyl arsenious oxide. Hazard Toxic by ingestion, inhalation, and skin absorption strong irritant. 

Chlordane (CAS 57-74-9) Irritating to skin. A CNS convulsant. Skin absorption is rapid and has caused convulsions and death. Hepato-toxic. Evidence of carcinogenicity in test animals (lARC 2B). See also p161. 0.5 mg/m. S,A3 100 mg/m Viscous amber liquid. Formulations vary in appearance. A chlorine-llke odor. Vapor pressure Is 0.00001 mm Hg at20°C (68°F). Not combustible. Thermal-breakdown products include hydrogen chloride, phosgehe, ahd chloride gas. EPA bahhed this insecticide in 1976. 

Endosulfan (CAS 115-29-7) Inhalation and skin absorption are major routes of exposure. Symptoms Include nausea, confusion, excitement, twitching, and convulsions. Animal studies suggest liver and kidney Injury from very high exposures. Limited evidence for adverse effects on male reproduction and fetal development In animal studies. See also p 161. 0.1 mg/m S Chlorinated hydrocarbon insecticide. Tan, waxy solid with a mild sulfur dioxide odor. Thermal-breakdown products include oxides of sulfur and hydrogen chloride. 

Synonyms Chlorinated polyethylene Chloroethene, compd. with ethene CPE Classification Olefin Properties Wh. gran. dens. 1.220 Toxicology May be harmful by inh., ing., or skin absorption may cause skin/eye irritation Precaution May dec. under fire conditions to form flamm./explosive mixts. in air Hazardous Decomp. Prods. CO, CO2, hydrogen chloride gas Uses Infoodpkg. 

Ideally, toxicology studies should mimic, as near as possible, human exposure. Thus, both the route of administration and the exposure should, where possible, be similar to that in man. The classic route of administration in man is oral and thus most toxicology studies are conducted by the oral route. Elowever, parenteral routes may be used either to mimic the clinical route or to ensure exposure. The administration of some medicines is directly on to highly differentiated surfaces such as the alveolar surface of the lungs or the skin. It is, therefore, important to assess the topical irritancy, absorption and subsequent systemic toxicity following such applications. It should be remembered that some compounds, for example, chlorinated hydrocarbons, may be more toxic when given by the inhalation route than when given orally or may directly affect... 

The findings of toxic effects in the heart, stomach, blood, muscles, and kidneys of humans who were dermally exposed to chromium compounds is suggestive of distribution to these organs (see Section 2.2.3.2). Fourteen days after a salve containing potassium chromate(VI) was applied to the skin of an individual to treat scabies, appreciable amounts of chromium were found in the blood (2-5 mg/100 mL), urine (8 mg/L), feces (0.61 mg/100 g), and stomach contents (0.63 mg/100 mL) (Brieger 1920). The preexisting condition of scabies or the necrosis caused by the potassium chromate could have facilitated its absorption. A transient increase in the levels of total chromium in erythrocytes and plasma was observed in subjects immersed in a tank of chlorinated water containing potassium dichromate(VI) (Corbett et al. 1997). 

Chlorine dioxide can be rapidly absorbed through the gastrointestinal tract. Peak blood concentration levels can be reached within Ih after a single dose administered orally. It can also be slowly absorbed through shaved skin with a half-absorption time of 22 h. Chlorine dioxide is metabolized to chlorite, chlorate, and mostly chloride. Most administered chlorine dioxide and its metabolites remain in plasma followed by kidneys, lungs, stomach, intestine, liver, and spleen. About 43% of orally administered chlorine dioxide is eliminated in the urine and feces within 72 h. It is not excreted via the lungs. 

The compounds that have been identified as xenoestrogens vary widely in chemical nature. Many are highly lipophilic and slowly metabolized (TCDD, chlorinated hydrocarbon pesticides). Others are less lipophilic and more labile (phthalates) and some are hydrophilic (methyl paraben, aluminum chloride, and aluminum chlorohydrate). It is known that lipophilic chemicals are more readily absorbed through the skin than hydrophilic chemicals, but as has been pointed out repeatedly in this book, lipophiles facilitate the absorption of hydrophiles and contribute to unexplained mixture effects. Table 22.3 lists some of the known xenoestrogens, types of products they are used in, and their K)w values. 

Experimental data on the percutaneous absorption of PCBs in humans is limited to in vitro studies thatused human cadaver skin (Wester et al. 1990,1993). These studies utilized "C-labeled Aroclor 1242 and 1254 (mixtures containing 42 or 54% chlorine by mass) in soil, mineral oil, and water. Over a... 

Dermal absorption of PCBs has been measured in monkeys and guinea pigs by comparing excretion following topical administration to excretion following parenteral administration. Single doses of " C-labeled PCBs (42% chlorine content) in benzene/hexane were applied to the abdominal skin of four... 

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