Acute oral toxicity

Acute oral toxicity is a measure of the harmful effects that a substance can cause when ingested orally. It is typically determined through laboratory testing on animals, and the results are used to classify the substance according to its level of toxicity. The LD50 (lethal dose, 50%) is a commonly used measure in these tests, representing the dose required to kill half the members of a tested population.

Definition

Acute toxicity refers to the adverse effects of a substance that result either from a single exposure or from multiple exposures in a short period of time (usually less than 24 hours). In the context of acute oral toxicity, the substance is ingested orally. The effects can range from mild irritation to severe damage to the gastrointestinal tract, and in extreme cases, death.

Testing

Acute oral toxicity is usually determined through laboratory testing on animals such as rats or mice. The animals are observed for a period of time after exposure, and the effects are recorded. The LD50 value is then calculated. This is the dose required to kill half the members of a tested population. The lower the LD50 value, the more toxic the substance is considered to be.

Classification

Based on the results of the LD50 tests, substances are classified into one of four categories according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Category 1 substances have the highest level of toxicity, while Category 4 substances have the lowest.

Regulation

Regulations regarding acute oral toxicity vary by country and by type of substance. In many countries, substances that are found to have a high level of acute oral toxicity are subject to restrictions or bans. In the United States, the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA) are among the agencies that regulate substances based on their acute oral toxicity.

See also

• Toxicity
• LD50
• GHS
• EPA
• FDA