SIST EN ISO 11348-3:2009 PDF

Overview

EN ISO 11348-3:2008 / ISO 11348-3:2007 specifies a standardized luminescent bacteria test using freeze‑dried Vibrio fischeri (NRRL B‑11177) to determine the inhibitory effect of water samples on bacterial light emission. The method is a rapid bioassay for water quality and ecotoxicity screening. It is applicable to wastewater, aqueous extracts and leachates, surface and ground water, sea and brackish water, sediment eluates, pore water and single substances diluted in water.

Key topics and technical requirements

• Principle: A batch test combines defined volumes of test sample (or dilutions) with a reconstituted suspension of freeze‑dried V. fischeri. Inhibition is assessed from the reduction in bioluminescence after specified contact times.
• Measurement times: Luminescence is measured after 15 min or 30 min (optionally 5 min) exposure; results incorporate a correction factor to account for intensity changes in controls.
• Endpoints: Results can be expressed as LID (luminescence inhibition degree) or as effective concentrations (e.g., EC20 / EC50) derived from a dilution series.
• Reagents and test organism: Freeze‑dried bacterial preparations are stored at approx. −18 °C to −20 °C and are ready for use immediately after reconstitution. A 20 g/L NaCl diluent is specified.
• Interferences and limits:
  • Colour, turbidity and light scattering can reduce apparent luminescence (sample pretreatment and colour‑correction options are provided).
  • High oxygen demand, very low dissolved oxygen or excessive biodegradable nutrients may artifactually reduce luminescence.
  • pH outside 6.0–8.5 affects results and may require adjustment.
  • High salt/osmolarity (>30 g/L NaCl or resulting osmolarity above ~35 g/L NaCl equivalent) can cause hyperosmotic effects-special guidance exists for saltwater samples.
• Validity and quality assurance: The standard defines criteria of validity, precision considerations and reporting requirements.

Applications and who uses it

• Environmental and regulatory laboratories performing toxicity screening and routine water quality monitoring.
• Wastewater treatment operators, environmental consultants and researchers assessing effluents, leachates, sediment eluates and pore waters.
• Chemical manufacturers and product safety assessors for rapid ecotoxicity pre‑screening of single substances diluted in water.
• Useful as a cost‑effective bioassay in integrated monitoring programs and as a complement to chemical analyses.

Related standards

• ISO 11348‑1: Method using freshly prepared bacteria
• ISO 11348‑2: Method using liquid‑dried bacteria
• ISO 5667‑16: Guidance on biotesting of samples (sampling)
• ISO 5814: Determination of dissolved oxygen (electrochemical probe)

Keywords: water quality, Vibrio fischeri, luminescent bacteria test, freeze‑dried bacteria, ISO 11348‑3, toxicity testing, EC50, wastewater monitoring.