Dermal

Health and Safety Factors. See "General Health and Safety Eactors." The following toxicides for adiponitrile have been reported oral LD q (rats), 300 mg/kg dermal LD q (rabbits), 2,134 mg/kg and inhalation 4-h LC q (i ts), 1.7 mg. NIOSH has proposed an exposure limit of 4 ppm as a TWA (68). 

Toxicity studies on trifluoroethanol show acute oral LD q, 240 mg/kg acute dermal LD q, 1680 mg/kg and acute inhalation L(ct) Q, 4600 ppmh. Long-term subchronic inhalation exposure to 50—150 ppm of the alcohol has caused testicular depression in male rats, but no effects were noted at the 10 ppm level (32). Although the significance of the latter observations for human safety is unknown, it is recommended that continuous exposure to greater than 5 ppm or skin contact with it be avoided. 

Health and Safety. The dermal toxicology of alkaline solutions of thioglycolic acid has been reviewed extensively (63—65). The reagent has been found harmless to normal skin when used under conditions adopted for cold waving. Some irritation is observed on abraded skin but this appears to be associated with the alkaline component of the waving solution (65). Hand protection is recommended for the professional hairdressers who routinely handle these products. 

Hydraziae is toxic and readily absorbed by oral, dermal, or inhalation routes of exposure. Contact with hydraziae irritates the skin, eyes, and respiratory tract. Liquid splashed iato the eyes may cause permanent damage to the cornea. At high doses it can cause convulsions, but even low doses may result ia ceatral aervous system depressioa. Death from acute exposure results from coavulsioas, respiratory arrest, and cardiovascular coUapse. Repeated exposure may affect the lungs, Hver, and kidneys. Of the hydraziae derivatives studied, 1,1-dimethylhydrazine (UDMH) appears to be the least hepatotoxic monomethyl-hydrazine (MMH) seems to be more toxic to the kidneys. Evidence is limited as to the effect of hydraziae oa reproductioa and/or development however, animal studies demonstrate that only doses that produce toxicity ia pregaant rats result ia embryotoxicity (164). 

The importance of hydrolysis potential, ie, whether moisture or water is present, is illustrated by the following example. In the normal dermal toxicity test, namely dry product on dry animal skin, sodium borohydride was found to be nontoxic under the classification of the Federal Hazardous Substances Act. Furthermore, it was not a skin sensitizer. But on moist skin, severe irritation and bums resulted. 

Although there is Httle toxicity information pubHshed on hydrides, a threshold limit value (TLV) for lithium hydride in air of 25 fig/has been established (52). More extensive data are available (53) for sodium borohydride in the powder and solution forms. The acute oral LD q of NaBH is 50-100 mg/kg for NaBH and 50-1000 mg/kg for the solution. The acute dermal LD q (on dry skin) is 4-8 g/kg for NaBH and 100-500 mg/kg for the solution. The reaction or decomposition by-product sodium metaborate is slightly toxic orally (LD q is 2000-4000 mg/kg) and nontoxic dermally. 

Dihydroxybenzenes (DHBs) are slightly more acutely toxic than phenol (Table 5). Contact with dihydroxybenzene through oral, dermal, or respiratory routes can induce significant systemic exposure. Skin or eye effects have been demonstrated during chronic or accidental professional exposure. No systemic effect has been described in such circumstances. 

In experimental animals and in vitro, DHBs show a variety of biological effects including binding of metaboHtes to various proteins. Clastogenic effects have been observed in vitro and in some in vivo studies with the three compounds. No reproductive effects have been shown by conventional studies with either hydroquinone, catechol, or resorcinol (122). Hydroquinone has been shown to induce nephrotoxicity and kidney tumors at very high doses in some strains of rat (123) catechol induces glandular stomach tumors at very high dose (124). Repeated dermal appHcation of resorcinol did not induce cancer formation (125). 

Imidocloprid [105827-78-9] l-[(6-chloro-3-pytidinyl)methyl]-N-nitro-2-imida2ohdininiine (4) (bp 137—144°C, vp 0.2 )J.Pa at 20°C) is soluble to 0.51 g/L. It is a synthetic nicotinoid with both contact and systematic activity against aphids, leafhoppers, whiteflies, and other sucking insects. The rat LD qS are 424 male, 475 female (oral), and 5000 (dermal) mg/kg. 

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