Overview
EN ISO 15088:2008 (ISO 15088:2007) specifies a standardized bioassay for assessing the acute toxicity of waste water to zebrafish eggs (Danio rerio). The method measures toxic effect after 48 h exposure and is applicable to raw, treated municipal waste water and industrial effluents. The test uses fertilized zebrafish eggs in a dilution series to determine the Lowest Ineffective Dilution (LID) or dose–response endpoints (e.g., EC50/LC50) expressed as percentages of waste water.
Keywords: EN ISO 15088:2008, ISO 15088:2007, water quality, acute toxicity, zebrafish eggs, Danio rerio, waste water testing.
Key topics and technical requirements
- Test organism and material: Fertilized eggs of Danio rerio (transparent, ~1 mm diameter), easy to maintain year‑round; embryonic development is well described.
- Test design: Dilution series of waste water in standard dilution water; exposure in single-use polystyrene microplates (24 wells), 2.5–5 ml per well.
- Duration and conditions: 48-hour exposure at 26 °C ± 1 °C with controlled illumination and aerated dilution water (100% O2 saturation before use).
- Endpoints: Determination of LID (dilution level with ≤10% affected eggs) and optionally EC50/LC50 values; evaluation of embryo mortality and defined developmental disturbances leading to death.
- Quality controls: Positive control using 3,4-dichloroaniline (3.7 mg/L) with 10 eggs; validity criteria and reproducibility requirements specified.
- Interferences: Guidance for coloured or turbid waste water (pre-differentiation, transfer procedures) to avoid misinterpretation.
- Apparatus & reagents: Inverse microscope (≥30×), pH and dissolved oxygen measurement (ISO 5814), standard dilution water composition per ISO 7346 series.
Practical applications and users
Who uses EN ISO 15088:2008:
- Environmental laboratories performing regulatory compliance and effluent monitoring
- Municipal wastewater treatment operators assessing final effluent toxicity
- Industrial environmental testing for discharge characterization
- Research labs studying developmental toxicity in aquatic organisms
Practical value:
- Replaces or supplements acute fish toxicity tests when egg-stage assays are preferred
- Rapid screening tool (48 h) for acute effects of complex effluents
- Facilitates dose–response determination and routine monitoring with standardized reproducibility
Related standards
- ISO 7346-1, ISO 7346-2 - acute fish toxicity methods and standard dilution water
- ISO 5667-16 - guidance on sampling for biotesting
- ISO 5814 - dissolved oxygen measurement
- OECD Guidelines (203, 204, 210) - referenced for broader fish testing practices
EN ISO 15088:2008 provides a practical, standardized approach for acute toxicity testing of waste water using zebrafish eggs, enabling consistent monitoring and regulatory reporting of effluent toxicity.
