Overview
ISO 19820:2016 specifies a standardized acute toxicity test using the marine rotifer Brachionus plicatilis to determine lethal effects (24 h and/or 48 h) of chemicals, effluents, waters and sediment elutriates. The method yields 24 h and 48 h LC50 values and is designed for environmental monitoring and ecotoxicological hazard assessment in marine and estuarine systems.
Key topics and technical requirements
- Test organism: female Brachionus plicatilis from culture or hatched from cysts (hatching procedure in Annex A).
- Exposure: 24 h and/or 48 h (48 h recommended for increased sensitivity).
- Environmental conditions: dark, temperature-controlled at 25 ± 1 °C; seawater salinity typically 29–36 ‰ for natural seawater; dissolved oxygen and pH measured per ISO 5814 and ISO 10523.
- Test design:
- Minimum of five concentrations in a geometric series; six replicates per concentration plus six controls.
- Range-finding dilution factors: ~10× for chemicals; 1:1 (halving) for effluents/waters.
- Definitive test dilution factor: separation factor ≤ 3.2 for chemicals; 1:1 for effluents/waters.
- Materials & apparatus: small Petri dishes, disposable 48-well microplates, stereomicroscope (≥8×), appropriate pipettes, artificial seawater recipe provided in Annex B.
- Reference substances: potassium dichromate (K2Cr2O7) or copper sulfate (CuSO4·5H2O) - note carcinogenicity risk with K2Cr2O7; ready-made standard solutions recommended.
- Sample handling: test within 12 h of collection when possible; cooling (0–5 °C) for up to 24 h or deep-freezing (below −18 °C) under controlled conditions; filtration/centrifugation/decantation allowed to remove particulates.
- Reporting & validity: standard defines validity criteria, LC50 estimation methods and required test report content.
Applications and users
Who uses ISO 19820:2016:
- Environmental and ecotoxicology laboratories performing marine acute toxicity tests
- Regulatory agencies assessing chemical hazards and discharge compliance
- Wastewater and industrial effluent monitoring programs
- Marine impact assessments and sediment elutriate testing
- Chemical manufacturers and consultants conducting product safety and risk evaluations
Practical applications:
- Screening chemicals and formulations for marine toxicity
- Routine monitoring of treated/untreated effluents and coastal waters
- Comparative toxicity testing using standardized LC50 endpoints
- Supporting environmental permitting and compliance with water quality regulations
Related standards
- ISO 5667-16 - Guidance on biotesting of samples (sampling, transport, storage)
- ISO 5814 - Determination of dissolved oxygen (electrochemical probe)
- ISO 10523 - pH determination
- ISO 6341 - Definitions for test batches and controls (referenced terms)
Keywords: ISO 19820:2016, Brachionus plicatilis, acute toxicity test, LC50, marine rotifer, water quality, ecotoxicology, effluent testing, sediment elutriate, seawater testing.