Division II.6.4.2.2.4

Although OECD Test Guideline 424 does not specifically address effects on the activity of acetylcholinesterase, this end point shall be included in all repeated dose toxicity studies for specific substances known or suspected to have such activity (for example, organophosphates or carbamates). Testing for cholinesterase inhibition shall at least include measurements in brain and erythrocytes.