1 Subject content and application scope
This standard specifies the methods, i.e., static method, semi-static method and flow-through method for the determination of the acute lethal toxicity of water-soluble substances under specified conditions, to Brachydanio rerio.
This standard is applicable to the toxicity determination of single chemical substance in water. This method may also be used for the toxicity determination of industrial wastewater. (See Annex A for the collection, storage, and interference treatment of wastewater samples.)
2 Principle
Determination, under specified conditions, of the concentrations at which a substance is lethal to 50% of a test population of Brachydanio rerio after exposure periods of 24h, 48h, 72h or 96h to that substance. These concentrations are designated as 24 h-LC50, 48 h-LC50, 72 h-LEO or 96h-LC50.
3 Definitions
3.1 static test
test carried out without renewing the test solution and limited to the study of substances, wherein, the chemical properties remain relatively constant
3.2 semi-static test
test which may be used for testing those substances, wherein, the concentrations are maintained satisfactorily (with fluctuations within 20% of the initial value) throughout the test by renewal of the solutions every 24h or less time
3.3 flow-through test
test which may be used for most types of substances, including those instable in water
4 Preparation of test organism and reagents
4.1 Test organism
The test species shall be Brachydanio rerio Hamilton-Buchanan (Teleostei Cyprinidae). Each test fish shall have a length of 30±5mm, which corresponds to a mass of 0.3±0.1g. They shall be selected from juvenile fish with the same size in a single stock. This stock shall have been acclimatized and, in any case, maintained for at least two weeks prior to the test in water, continuously aerated using bubbled air, under conditions similar to those used in the test. They shall be fed as normal up to the 24h period immediately preceding the test. Feces and food residues are removed every day. The death rate during the period of domestication shall not exceed 10%; otherwise, this shoal of fishes shall not be taken for test.
1 Subject content and application scope
2 Principle
3 Definitions
4 Preparation of test organism and reagents
5 Instruments
6 Test conditions
7 Test procedure
8 Expression of results
9 Test report
Annex A (Supplement) Collection and treatment of wastewater samples
Annex B (Supplement) Environmental parameters for maintenance and breeding of Brachydanio rerio Hamilton-Buchanan
Annex C (Supplement) Observation record for acute toxicity of Brachydanio rerio
Annex D (Normative) Table for conversion of percentage and probability units
Additional information
