Solvents skin absorption

Strong acids and strong alkaUes can severely bum the skin, chromium compounds can produce skin rashes, and repeated exposure to solvents causes removal of natural oils from the skin. Infection is always a concern for damaged skin. Absorption through the skin is possible for materials that are appreciably soluble iu both water and oil, eg, nitrobenzene, aniline, and tetraethyllead. Other materials can be absorbed if first dissolved iu extremely good solvents, eg, dimethyl sulfoxide. Subcutaneous iujection can occur accidentally by direct exposure of the circulatory system to a chemical by means of a cut or scratch or iuadvertent penetration of the skin with a hypodermic needle. 

Direct contact with the liquid may cause erythema and vesiculation prolonged or repeated contact has been associated with the development of a dry, scaly dermatitis or with secondary infections. Some skin absorption can occur with lengthy exposure to solvents containing benzene and may contribute more to toxicity than originally believed, but the dermal route is considered only a minor source of exposure for the general population. ... 

Solvents are well absorbed following oral or skin exposure. Most solvents are quickly absorbed from the gut, although the presence of food may delay absorption. Alcohol is a good example of a solvent typically consumed orally. The skin offers little barrier to solvents. Skin exposure to solvents can result in local irritation and increased blood levels of the solvent. 

Skin absorption Exposure to and absorption of a compound via the skin Nicotine patch, solvents... 

Methanol is widely used as a solvent and as a denaturing agent for ethanol and is also found in antifreeze. Mass poisonings have occurred because of ingestion in alcoholic drinks made with contaminated ethanol as well as from accidental exposure. Inhalation and skin absorption may cause toxicity. In humans, about 10 mL can cause blindness and 30 mL is potentially fatal, but there is variation in the lethal dose. 

Note Highly polar solvent sweet, ethereal odor soluble in water flammable, burns with a luminous flame highly toxic by ingestion, inhalation and skin absorption miscible with water, methanol, methyl acetate, ethyl acetate, acetone, ethers, acetamide solutions, chloroform, carbon tetrachloride, ethylene chloride, and many unsaturated hydrocarbons immiscible with many saturated hydrocarbons (petroleum fractions) dissolves some inorganic salts such as silver nitrate, lithium nitrate, magnesium bromide incompatible with strong oxidants hydrolyzes in the presence of aqueous bases and strong aqueous acids. Synonyms methyl cyanide, acetic acid nitrile, cyanomethane, ethylnitrile. 

Note Moderately polar, weakly hydrogen bonding solvent, heavy liquid gradually decomposes to acquire a yellow color, air and light will accelerate this decomposition nonflammable commercial product is often stabilized by the addition of 3 to 4% (mass/mass) alcohols highly toxic by ingestion, inhalation, and skin absorption soluble in alcohols, organohalogen compounds, hydrocarbons, benzene, and many oils incompatible with many alkali and alkaline earth metals. Synonyms tribromomethane. 

Note Nonpolar solvent soluble in alcohols, ethers, chloroform, benzene, and most fixed and volatile oils insoluble in water nonflammable extremely toxic by inhalation, ingestion, or skin absorption carcinogenic incompatible with allyl alcohol, silanes, triethyldialuminum, and many metals (e.g., sodium). Synonyms tetrachloromethane, perchloromethane, methane tetrachloride, Halon-104. 

Note Polar solvent soluble in alcohols, ether, benzene, and most oils usually stabilized with methanol to prevent phosgene formation flammable and highly toxic by inhalation, ingestion, or skin absorption narcotic carcinogenic incompatible with caustics, active metals, aluminum powder, potassium, sodium, magnesium. Synonyms trichloromethane, methane trichloride. 

Note Nonpolar hydrocarbon solvent mild, gasoline-like odor soluble in hydrocarbons, alcohols, organic halides, acetone, benzene flammable moderately toxic by inhalation, ingestion, or skin absorption, may be narcotic at high concentrations reacts with oxygen (air) at elevated temperatures decomposes upon heating incompatible with strong oxidants. Synonyms benzene hexahydride, hexameth-ylene, hexanaphthene, hexahydrobenzene. 

Note Polar solvent soluble in water, alcohols (organic halides), ether, and many oils flammable moderately toxic by inhalation and skin absorption incompatible with strong oxidizers, nitrates, strong alkalis, strong acids. Synonyms acedin, acetic ether, acetic ester, ethyl ethanoate, vinegar naphtha, acetic acid ethyl ester. 

Similarly, ordinary handling of the methyl and methyl phenyl silicone polymers of all the types described and of their intermediate condensation products as well has not resulted in a single symptom of toxicity. The oils appear to be bland and to cause no skin disorders the resins are sticky but are readily washed off the skin with hydrocarbon solvents. The absorption of oil and resin through the skin seems to be inconsequential. 

Studies conducted in vivo in humans and in vitro using human skin indicate that benzene can be absorbed dermally. The data show that dermal absorption is not as substantial as absorption following inhalation exposure to benzene vapor or oral exposure. The movement of a substance through the skin to the blood occurs by passive diffusion and has been described mathematically by Fick s law. However, this is an oversimplification of the process of skin absorption various factors (e.g., interaction of benzene with molecules within the skin) affect the transport of the solvent through the skin (Loden 1986). 

Several in vivo and in vitro studies conclusively demonstrate that benzene can be absorbed through human skin (Blank and McAuliffe 1985 Franz 1984 Susten et al. 1985 Tsuruta 1989). In general, skin absorption is considered a minor source of concern in the occupational environment as it occurs at a much lower rate and extent compared with benzene absorption through the respiratory system (OSHA 1989). However, benzene absorption through the skin as a result of benzene contamination in rubber solvents is a major route of exposure in tire building operations (Susten et al. 1985). Benzene is an irritant to the skin and, by defatting the keratin layer, may cause erythema, vesiculation, and dry and scaly dermatitis... 

Tsuruta H. 1989. Skin absorption of organic solvent vapors in nude mice in vivo. Ind Health 27 37-47. 

Ingestion of methanol (or methyl alcohol) has been reported among alcoholics, following exposure to industrial solvents [88], and in counterfeit or bootleg wood alcohol poisoning outbreaks [89]. Poisoning may infrequently follow inhalation or skin absorption. Methanol absorption from an empty stomach follows... 

Defining the amount of the topical dose applied that is available for absorption is particularly challenging when the compound under investigation is volatile or semivolatile as in the case of solvents and insect repellents. Following topical application, some of the applied dose will penetrate the skin and be absorbed. At the same time, some fraction will evaporate slowly from the surface of the skin and be lost, unavailable for percutaneous absorption. It has been demonstrated that the rate of evaporation, and consequently the relationship between evaporation and skin penetration, can influence the quantity of chemical absorbed dermally. The extent of evaporation from the skin surface is a function of the dose applied, airflow, and temperature at the skin surface. The extent to which these variables may be controlled or monitored can have a major impact on the results of in vivo skin absorption studies. Furthermore, consideration of the evaporative loss of the... 

Hazard Toxic by ingestion, inhalation, and skin absorption irritant to skin and eyes. Flammable, dangerous fire risk. TLV 100 ppm STEL 125 ppm. Use Intermediate in production of styrene, solvent. 

They are toxic hy ingestion and skin absorption. Xylenols are used in chemical organic S3mthesis and also as solvents. Their uses have been shown vide Fig. 1.2... 

Solvent extraction has been demonstrated to be effective against HD exposures (Smith et al., 1919) but is less likely to completely remove contamination than debridement and the use of flammable solvents is perhaps not a practical option for battlefield conditions. Furthermore, no single solvent may be appropriate for all agents and the use of an inappropriate solvent may actually enhance skin absorption and toxicity. 

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