Pesticide Registration Toolkit

#624 28-day delayed neurotoxicity (hen)

Objective of the study

The objective of the 28-day delayed neurotoxicity study is to assess the potential of certain classes of substances to cause delayed neurotoxicity or delayed polyneuropathy following repeated exposure.
 

Circumstances under which the study is recommended to be required

The 28-day delayed neurotoxicity study is recommended if results of acute neurotoxicity study indicate significant statistical or biological effects or if other available data indicate the potential for this type of delayed neurotoxicity, as determined by the responsible authority.
 

Test organism

The 28-day 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 28-day delayed neurotoxicity study include (among others):
  • toxic response data, including mortality;
  • nature, severity and duration of clinical observations (whether reversible or not);
  • no-observed-adverse effect level;
  • biochemical findings;
  • histopathological findings.
 

Test guidelines

The following test guidelines may be used for the 28-day delayed neurotoxicity study: