ISO 12890 pdf download.Water quality — Determination of toxicity to embryos and larvae of freshwater fish — Semi-static method
1 Scope
This International Standard specifies a semi-static method for determination of toxicity of chemicals, waters and wastewaters to embryos and early larval developmental stages of a species of freshwater fish, Danio rerio (Hamilton-Buchanan), Teleostei, Cyprinidae (common name zebrafish). Where necessary this determination may include an acute toxicity test using Danio rerio to determine the 96-h LC 50 for zebrafish in accordance with ISO 7346-1 , ISO 7346-2 or ISO 7346-3. The method is also applicable to freshwater fish other than zebrafish if appropriate modifications of the test conditions are made, particularly with regard to the temperature and volume per fish biomass.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 5667-1 6, Water quality — Sampling — Part 1 6: Guidance on biotesting of samples . ISO 6341 , Water quality — Determination of the inhibition of the mobility of Daphnia magna Straus (Cladocera, Crustacea) — Acute toxicity test . ISO 7346-1 , Water quality — Determination of the acute lethal toxicity of substances to a freshwater fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] — Part 1 : Static method . ISO 7346-2, Water quality — Determination of the acute lethal toxicity of substances to a freshwater fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] — Part 2: Semi-static method .
4 Principle
Newly fertilized eggs are exposed to a series of concentrations of the sample to be tested, including controls (concentration 0). For practical reasons, for the purposes of this International Standard eggs are regarded as embryos. The number of surviving and hatched eggs or larvae is recorded daily in all test solutions, which are renewed daily (semi-static method). No food is provided. The standard period of exposure for this test is 1 0 days, but the test may be prolonged up to 1 4 days in order to increase its sensitivity if desired. The entire procedure, including preparation and calculations, takes about 4 weeks. The data obtained are used for calculations of the median times for hatching and survival in the tested concentrations and in the controls. No effect concentrations (NECs) are determined from the concentration-effect relationships for hatching and survival. Effect concentrations with desired percentage effects (EC X s) can also be determined, and the results can also be evaluated with regard to the highest concentration without significant effect (NOEC) and the lowest concentration with significant effect in relation to the controls (LOEC). Prior to the determination it may be useful to determine the acute toxicity of the sample (the 96-h LC 50 ) to zebrafish in accordance with ISO 7346-1 , ISO 7346-2 or ISO 7346-3.
5 Test environment
Carry out the storage of the solutions and the exposure of test organisms as described in this International Standard under normal laboratory illumination with a 1 2 h/1 2 h, a 1 4 h/1 0 h or a 1 6 h/8 h light/dark exposure period. Stock solutions may be stored refrigerated and/in darkness when appropriate. Maintain the testing atmosphere at 26 ?C ? 2 ?C and free from vapours or dusts toxic to the test organism. Stock storage of fish and all handling and testing shall take place in rooms where air is free from hazardous concentrations of dust and toxic vapour.