Dose-scaling

Toxicological equivalent doses in animals and humans are a debatable issue. The Joint FAOIWHO Expert Committee on Food Additives (JECFA) and Joint FA01 WHO Meetings on Pesticide Residues (JMPR) have typically used mg per kg of body weight for interspecies scaling. Recently, regulatory authorities in the USA have proposed a scaling equivalent to mg per 0.75 kg of body weight, which is based on more recent pharmacokinetic information. The ideal scaling factor would be obtained by measuring tissue concentrations and clearance rates in the target organ of the animal and human. Generic interspecies scaling factors should be recognized as default values that are used in the absence of better information, which is seldom available