Dermal absorption/toxicity

The water solubiUty of glutaric acid fosters its toxicity. Glutaric acid is a known nephrotoxin. Renal failure has been documented ia rabbits adruinistered sodium glutarate subcutaneously (124). Dibasic ester (Du Pont), which contains primarily dimethyl glutarate, has low acute toxicity by inhalation and by ingestion, and is moderately toxic via dermal absorption. The acid is both a dermal and ocular irritant of humans. The ester is a severe skin irritant and may cause a rash ia humans (120). 

Generally, the main pathways of exposure considered in tliis step are atmospheric surface and groundwater transport, ingestion of toxic materials that luu c passed tlu-ough the aquatic and tcncstrial food chain, and dermal absorption. Once an exposure assessment determines the quantity of a chemical with which human populations nniy come in contact, the information can be combined with toxicity data (from the hazard identification process) to estimate potential health risks." The primary purpose of an exposure assessment is to... 

EPA. 1990a. Endosulfan Review of four toxicology studies and three dermal absorption studies. Memorandum. Washington, DC U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances. Document no. 007937. 

Dermal Absorption. To determine the toxicity of parathion following dermal application, the method of Draize, Woodard, and Calvery (3) was followed. Variables considered in the design of these experiments were concentration as a factor of area, solvent, exposure time, and number of exposures. In some cases the wettable powder was applied in the dry form, while in other cases sufficient water was added to produce a viscid paste. All doses in the table are presented as milligrams per kilogram of parathion, regardless of the concentration or solvent. 

Dermal Absorption and Toxicity Assessment, edited by Michael S. Roberts and Kenneth A. Walters... 

Recycling of printer circuit boards is deemed as the most important source of heavy metals to the ambient environment. These heavy metals may be entering into human body from various exposure routes such as ingestion, inhalation, and dermal absorption. Exposure to high levels of heavy metals can lead to acute and chronic toxicity, such as damage to central and peripheral nervous systems, blood composition, lungs, kidneys, liver, and even death [14],... 

Fenvalerate toxicity is antagonized by atropine sulfate or methocarbamol, which may be effective in treating severe cases of poisoning (Hiromori et al. 1986). Conversely, some compounds exacerbate the toxicity of fenvalerate and interfere with a desired use. Domestic cats (Felis domes-ticus) treated with Fendeet (an aerosol mixture of fenvalerate and A-A-diethyl-m-toluamide) to control fleas and ticks sometimes show signs of toxicosis, such as tremors, hypersalivation, ataxia, vomiting, depression, and seizures. Signs usually appeared within hours of topical application, and females and juveniles seem to be the most sensitive groups. The demonstrated ability of N-N-diethyl-m-toluamide to enhance the dermal absorption of fenvalerate is the probable cause of toxicosis (Dorman et al. 1990). 

Injection, inhalation, and dermal absorption generally result in the toxicant entering the bloodstream unaltered. Toxicants entering through ingestion are frequently modified or excreted in bile. 

Toxicants that enter by injection and dermal absorption are difficult to measure and quantify. Some toxicants are absorbed rapidly through the skin. 

The kidneys are the dominant means of excretion in the human body. They eliminate substances that enter the body by ingestion, inhalation, injection, and dermal absorption. The toxicants are extracted by the kidneys from the bloodstream and are excreted in the urine. 

Hotchkiss, S.A., Dermal metabolism, in Dermal Absorption and Toxicity Assessment. Drugs and the Pharmaceutical Sciences, Vol 91, Robberts, M.S. and Walters, K.A., eds., New York, Marcel Dekker, 43-101 (1998). 

Hexachloroethane caused reversible corneal injury in rabbits following ocular contact, but contact with the skin for 24 hours resulted in no dermal effects (Weeks et al. 1979). The physical properties of hexachloroethane suggest that absorption across human skin would be limited (Fiserova-Bergerova et al. 1990). Therefore, unless dermal absorption studies indicate that this prediction is incorrect, there is no need for additional studies of acute dermal toxicity. 

Therefore, unless dermal absorption studies indicate that this prediction is incorrect, there is no need for additional studies of intermediate dermal toxicity. 

Dermal exposure of rats and rabbits to endrin resulted in toxicity and death (Gaines 1960 Treon et al. 1955), indicating that percutaneous absorption of endrin occurs. It is likely that occupational poisonings reported by Hoogendam et al. (1962, 1965) also involved dermal absorption, but the extent and relative contribution of dermal exposure cannot be determined. Data describing the rate or extent of dermal absorption were not located. 

S. A. Hotchkiss. Dermal absorption. In M. Roberts and K. A. Walters (eds.), Dermal Absorption and Toxicity Assessment, Marcel Dekker, New York Basel, 1998, pp. 43-101. 

When it is absorbed through the lungs, gut, or skin, phenol enters the bloodstream where it can then be distributed throughout the body. The dilution of phenol in water enhances the dermal absorption of phenol, as indicated by the greater toxicity of a water-phenol solution compared to neat phenol (Conning and Hayes 1970). 

Animal data include an inhalation study in rabbits that resulted in an increased incidence of retroesophageal right subclavian artery in the fetuses (Hayes et al. 1985), and an oral study in rats that resulted in an increased incidence of an extra rib (NTP 1987). The data were considered sufficient to derive an acute-duration inhalation MRL of 0.8 ppm, based on a NOAEL of 300 ppm for lack of developmental effects in rabbits. It would be useful to have additional information on the developmental effects of 1,4-dichlorobenzene by inhalation and oral exposure in relation to maternal toxicity. There are currently no data available for the dermal route. Information on the developmental effects of dermal exposures would be useful if dermal absorption and systemic distribution of 1,4-dichlorobenzene could be demonstrated in toxicokinetic studies. 

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