A Note on Glycerol Formal as a Solvent in Toxicity Testing

Twenty‐nine organic solvents and emulsifying agents, selected for possible use as injection solvents in toxicity testing, have been submitted to a “range‐finding” toxicity screening test on rats. As a result, glycerol formal was examined in greater detail. Glycerol formal is a good inert solvent for a wide range of organic chemicals. It produced no toxic effects or macroscopic pathology when 1500 mg./kg. was administered intraperitoneally to rats, or 1000 mg./kg. to mice or guinea pigs, or 4000 mg./kg. orally to rats, and at high doses the only specific effect found was narcosis. It was correspondingly innocuous subcutaneously or dermally, and was almost non‐irritant to the eye surface. There was no detectable effect on the toxicity of parathion. Glycerol formal appears to be a useful addition to the range of solvents suitable for use in toxicity tests.