Overview
ISO 14669:1999 specifies a standardized laboratory method for assessing acute lethal toxicity to marine copepods (Copepoda, Crustacea). The method determines median lethal concentrations (LC50) after 24 h and 48 h exposure to chemical substances (soluble or stably dispersed), industrial or sewage effluents, and marine/estuarine waters. The standard covers test design, culture and selection of test species, environmental conditions, sampling and sample preservation, and result reporting.
Key topics and technical requirements
- Test organisms: one of three marine copepods - Acartia tonsa, Tisbe battagliai, or Nitocra spinipes. Specified life stages are required (e.g., A. tonsa stage 5 copepodids or adults; T. battagliai copepodids 6 ± 2 days; N. spinipes adults 3–4 weeks).
- Endpoints: 24 h and 48 h LC50 (48 h LC50 is the primary endpoint); 96 h may be used where appropriate. Also record the lowest concentration causing 100% mortality and the highest with no mortality.
- Test design: preliminary broad-range test (to define concentrations) followed by definitive test (replicated series). Minimum of 20 copepods per concentration in definitive tests (e.g., four replicates of five).
- Environmental controls: temperature 20 °C ± 2 °C, 16 h/8 h light/dark photoperiod, appropriate seawater salinity and dissolved oxygen (>80% air saturation) and pH control. Copepod density limits are specified (not to exceed 1 per 0.5 ml; for A. tonsa recommended max 1 per 5 ml).
- Sample and solution preparation: guidance on sampling (see ISO 5667-2, ISO 5667-16), stock solution preparation (including handling poorly soluble substances using ultrasonic or solvent assistance), and limit test at 100 mg/L or the maximum soluble concentration.
- Quality control: use of a reference toxicant (recommended 3,5‑dichlorophenol) to verify culture sensitivity and method conformity. Record dissolved oxygen and pH at test start and end; scoring of mortality uses a 10 s observation rule for movement.
Applications and users
- Environmental testing laboratories performing marine ecotoxicity and water quality testing
- Regulatory agencies evaluating chemical hazards, effluent permits and environmental compliance
- Industrial and municipal wastewater monitoring (effluent toxicity screening)
- Environmental consultants and researchers conducting biotesting, impact assessments, and method development
Practical uses include deriving LC50 values for risk assessment, screening effluents and chemicals for acute marine toxicity, and validating organism sensitivity with reference toxicants.
Related standards
- ISO 5667-2 - Water quality - Sampling: guidance on sampling techniques
- ISO 5667-16 - Water quality - Sampling: guidance on biotesting of samples
- ISO 14669 includes informative annexes with example calculations, culture methods for the three copepod species, and precision data.
Keywords: ISO 14669, acute lethal toxicity, marine copepods, LC50, water quality testing, ecotoxicology, effluent testing, biotesting, marine toxicology.