Acute dermal toxicity is the adverse effects occurring within a short time of dermal application of a single dose of a substance or multiple doses given within a 24-hour period.
Dosage is a general term comprising the dose, its frequency and the duration of dosing.
Dose is the amount of test substance applied. Dose is expressed as weight of test substance (grams, milligrams) per unit weight of test animal (e.g., milligrams per kilogram).
Dose-effect is the relationship between the dose and the magnitude of a defined biological effect either in an individual or in a population sample.
Dose-response is the relationship between the dose and the proportion of a population sample showing a defined effect.
LD50 (median lethal dose), dermal, is a statistically derived estimate of a single dose of a substance that can be expected to cause death in 50% of treated animals when applied to the skin. The LD50 value is expressed in terms of weight of test substance per unit weight of test animal (milligrams per kilogram).
40 C.F.R. §799.9120