The fish acute toxicity test is a mandatory component in the base set of data requirements
for ecotoxicity testing. The fish acute toxicity test is not compatible with most
current animal welfare legislation because mortality is the primary endpoint and it
is often hypothesized that fish suffer distress and perhaps pain. Animal alternative
considerations have also been incorporated into new European REACH regulations through
strong advocacy for the reduction of testing with live animals. One of the most promising
alternative approaches to classical acute fish toxicity testing with live fish is
the fish embryo toxicity (FET) test. The FET has been a mandatory component in routine
whole effluent testing in Germany since 2005 and has already been standardized at
the international level. In order to analyze the applicability of the FET also in
chemical testing, a comparative re-evaluation of both fish and fish embryo toxicity
data was carried out for a total of 143 substances, and statistical approaches were
developed to evaluate the correlation between fish and fish embryo toxicity data.
Results confirm that fish embryo tests are neither better nor worse than acute fish
toxicity tests and provide strong scientific support for the FET as a surrogate for
the acute fish toxicity test.