Pesticide Registration Toolkit

#1003 Fish toxicity - acute toxicity

Fish toxicity – acute toxicity

Objective of the study

The objective of the study is to generate data on the acute toxicity of a pesticide active ingredient or formulated pesticide product to fish.

Circumstances under which the study is recommended to be required

Data with the technical-grade active ingredient (TGAI) are recommended to support all outdoor end-use product uses, including turf. Data are generally not recommended to support end-use products in the form of a gas, a highly volatile liquid, a highly reactive solid, or a highly corrosive material.

Principle of the study

The fish are exposed to the test chemical for a period of 96 hours, under either static, semi-static or flow-through conditions. Mortalities and visible abnormalities related to appearance and behavior are recorded. Where possible, the concentrations to kill 50% of the fish (LC50) are determined.

Test organism or substrate

The selection of species depends on regulatory requirements (industrial chemical, pharmaceutical, biocide or plant protection product, etc.) and on environmental exposure scenarios (cold, temperate or warm water species, freshwater or estuarine/marine fish). Cold water fish are considered those that require holding temperatures below 20°C whilst warm water fish are typically kept in temperatures over 20°C. Temperate fish species prefer temperatures between 18-22°C.

A list of recommended fish species for this test is provided the table below. These fish species are readily available, are easy to maintain, and most have historical use in chemical safety testing. They can be bred and cultivated either in fish farms or in the laboratory, under disease-free conditions, providing healthy animals of known provenance for testing. If species that are not listed in the table are used, the rationale must be reported together with any adaptations to the test guideline’s recommendations.

 

Species

Temperature (°C)

Salinity (‰)

pH

Hardness (mg/LCaCO3)

Photoperiod (hourslight)

Recommended

lengthrange (cm)

Daniorerio

Zebrafish

21-25

<0.2

6.0-8.5

40-250, preferably<180

12-16

1-2

Pimephales promelas

Fatheadminnow

21-25

<0.2

6.0-8.5

40-250, preferably<180

12-16

1-3

Cyprinus carpio

Carpe

20-24

<0.2

6.0-8.5

40-250, preferably<180

12-16

2-4

Oryzias latipes JapaneseMedaka

23-27

<0.2

6.0-8.5

40-250, preferably<180

12-16

1-2

Poecilia reticulata

Guppy

21-25

<0.2

6.0-8.5

40-250, preferably<180

12-16

1-2

Lepomis macrochirus

Bluegill

21-25

<0.2

6.0-8.5

40-250, preferably<180

12-16

1-3

Oncorhynchus mykiss

Rainbow trout

10-1410

<0.2

6.0-8.5

40-250, preferably <180

12-16

3-6

Gasterosteus aculeatus

Three-spined stickleback

13-19

0-35

6.0-8.5

40-7500

12-16

1-2

Cyprinodon variegatus

Sheepshead minnow

23-27

15-35

6.0-8.5

3000-7500

12-16

1-2

Dicentrarchus labrax

European sea bass

18-22

15-35

6.0-8.5

3000-7500

12-16

4-8

Pagrus major

Red sea bream

18-22

30-35

6.0-8.5

5000-7500

12-16

2-4

 

Test substance

Technical grade active ingredient

A study with the end-use product is recommended to be required if the toxicity of the pesticide product cannot be reliably predicted on the basis of the active ingredient alone.

Typical endpoints of the study

  • the LC50 values at 24, 48, 72 and 96 hours with 95% confidence limits, if possible;
  • the slope of the concentration-response curve after 96 hours exposure, if possible;
  • graph of the concentration-mortality curve at the end of the exposure, if possible;
  • incidence and description of visible incidents;
  • incidents in the course of the test which might have influenced the results.

Testing guidelines

The following test guidelines may be used for determination of the acute toxicity of a pesticide to fish: