Pesticide Registration Toolkit

#623 Delayed neurotoxicity following acute exposure (hen)

Objective of the study

The objective of this delayed neurotoxicity study is to assess the potential of certain classes of substances to cause delayed neurotoxicity or delayed polyneuropathy following acute exposure.
 

Circumstances under which the study is recommended to be required

The delayed neurotoxicity study following acute exposure is recommended if the test material is an organophosphorus substance, which includes uncharged organophosphorus esters; thioesters or anhydrides of organophosphoric, organophosphonic, or organophosphoramidic acids; or of related phosphorothioic, phosponothioic, or phosphorothioamidic acids; or is structurally related to other substances that may cause the delayed neurotoxicity sometimes seen in this class of chemicals.
 

Test organism

The delayed neurotoxicity study is conducted with the adult domestic hen.
 

Test substance

Technical grade active ingredient
 

Typical endpoints of the study

Typical endpoints of the delayed neurotoxicity study include (among others):
  • toxic response data, including mortality;
  • nature, severity and duration of clinical observations (whether reversible or not);
  • biochemical findings.
 

Test guidelines

The following test guidelines may be used for the delayed neurotoxicity study following acute exposure: