Chapter 02 · Nature, land & waterWater, Waste & Pollution
Acute toxicity
Definition
A health hazard class describing adverse effects that occur following oral or dermal administration of a single dose, multiple doses within 24 hours, or an inhalation exposure of four hours. Under the UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS), acute toxicity is divided into five hazard categories per exposure route, ranked by severity.
References
GHS definitions of hazard class and hazard category; oral acute toxicity's five categories; classification framework.
GHS structure (physical, health, environmental hazard groups); acute toxicity as a health hazard class; purple book revision cycle.
GHS voluntary status at UN level, binding when transposed nationally; acute toxicity among consensus health classes.
Overview
What it means
Acute toxicity is distinct from chronic toxicity (harm from repeated or prolonged exposure) and from hazard classes such as carcinogenicity. GHS classification determines the symbols, signal words and hazard statements on labels and safety data sheets. The corresponding environmental classes cover acute and chronic hazards to the aquatic environment.
How it is used
Regulators and companies use acute toxicity classifications to control chemical handling, transport and worker protection, and to communicate hazards to downstream users. The GHS is voluntary at the international level but becomes binding where countries transpose it into national law; criteria are published in the UNECE "purple book", revised roughly every two years.
Why it matters
Harmonised acute toxicity classification underpins chemical safety, trade and pollution prevention worldwide. In sustainability assessment it feeds life-cycle toxicity indicators and chemical-footprinting, and it is central to due diligence on chemicals in supply chains.