Toxic effects of solvents on other organisms

In addition to humans, microorganisms animals and plants are also exposed to solvents. The interaction between organisms and solvents are often specific. For example, the reactions elicited by certain solvents depend on the species and abilities of the particular organism affected. 

As with all carcinogens the carcinogenic potency of solvents has been assessed by short-term in vitro tests, e. g., Ames assay, by long-term tumor induction experiments in animals and - especially important for the evaluation of the carcinogenic action in humans -prospective and retrospective epidemiological studies, for solvent exposure mainly in work places. 

In accordance with the evidence available, different classes for chemical carcinogens have been developed by health authority organizations. Examples ofthe classification of carcinogenic solvents are presented in Table 20.1.3. 

Bromomethane upper gastrointestinal, tract and respiratory, tract (animals) 3 K3 n.c. 3 n.l.  

Carbon tetrachloride lymphatic system, liver (mice, rats), mamma (rats), suprarenal gland (mice) 3 K3 A2 2B R 

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The environmental impacts of both the solvent to be replaced and the replacement solvent are considered using two indexes an air index and an overall environmental index. Since the object here is to formulate substitute solvents that have better environmental performance, the indexes for the solvent to be replaced are not matched but are rather treated as an upper bound on the indexes of the acceptable replacement. This insures that the replacement solvent is environmentally better than the original solvent as measured by the indexes. The inherent toxic effects of the solvent and the toxic effects due to volatile organic emissions are considered separately because, when chemicals are mixed, their volatility changes due to the non-idealities in the mixture. Therefore, a chemical that has low risk by inhalation due to low volatility in pure form can have a much higher volatility and a much higher risk when mixed with other chemicals. The air index,... 

There are a wide variety of solvents used in industrial processes, and exposure can also occur in other occupational settings such as laboratories and workshops. Solvents can have toxic effects ranging from narcosis, irritation, and degreasing of skin to effects on major organs such as the central nervous and reproductive systems. The trend of inhaling solvents, for their narcotic effects, which became popular in teenagers will be discussed on p. 198. 

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