Objective of the study

The studies, data and information to be provided should allow the identification of effects following a single exposure to the pesticide, and in particular to establish, or indicate:

• the toxicity of the active ingredient and formulated product;
• the time course and characteristics of the effects with full details of behavioural changes and possible gross pathological findings at post-mortem; and
• where possible mode of toxic action.

While the emphasis should be on estimating the toxicity ranges involved, the information generated should also permit the active ingredient to be classified regarding its acute hazard.

The information generated through acute toxicity testing is of particular value in assessing hazards likely to arise in accident situations.

Circumstances under which the study is recommended to be required

The acute oral toxicity study should always be conducted, except if the pesticide is a gas or a highly volatile liquid.

Test organism

The study is normally conducted in rats.

Test substance

• Technical grade active ingredient
• Formulated product
• If relevant, testing of the diluted end-use product is recommended

Typical endpoints of the study

Mortality: oral LD50 (mg a.i. / kg bw)

Test guidelines

The following test guidelines may be used for determination of the acute oral toxicity:

• OECD Guidelines for the Testing of Chemicals. Test No. 420: Acute Oral Toxicity – fixed dose procedure.
• OECD Guidelines for the Testing of Chemicals. Test No. 425: Acute Oral Toxicity – up and down procedure.
• US EPA Health Effects Test Guidelines. OPPTS 870.1100: Acute Oral Toxicity
• EC Testing Method B.1bis. Acute oral toxicity – fixed dose procedure. Council Regulation (EC) No 440/2008 – Annex Part B.