ISO 11348-2:2007

Overview

ISO 11348-2:2007 specifies a standardized luminescent bacteria test for water quality using liquid‑dried Vibrio fischeri (NRRL B‑11177). The method quantifies the inhibitory effect of a water sample on the light emission of V. fischeri to assess acute toxicity. Applicable matrices include wastewater, aqueous extracts and leachates, freshwater (surface and groundwater), seawater and brackish water, sediment eluates, pore water and single substances diluted in water.

Keywords: ISO 11348-2:2007, Vibrio fischeri, luminescent bacteria test, liquid-dried bacteria, water quality, toxicity testing, luminescence inhibition.

Key topics and technical requirements

• Test principle: Batch contact of sample with a bacterial suspension; measure luminescence after defined contact times (optionally 5 min, standard 15 min or 30 min) and calculate inhibition.
• Endpoints reported: Inhibition metrics such as LID (Luminescence Inhibition Dose) or effective concentration values (e.g., EC20, EC50) from dilution series.
• Reagents & media:
  • Liquid‑dried V. fischeri stored at ≤ −18 °C and reconstituted prior to testing.
  • Diluent: 20 g/L NaCl solution.
  • Test solution for reconstituted bacteria (per litre): 8.0 g D‑glucose monohydrate; 20.0 g NaCl; 2.035 g MgCl2·6H2O; 0.30 g KCl; 11.9 g HEPES; pH adjusted to 7.0 ± 0.2.
• Environmental/operational controls:
  • Test temperature: 15 °C ± 1 °C (thermo‑block/luminometer cell).
  • Oxygen requirement: samples must have > 3 mg/L dissolved O2 or be oxygenated prior to testing.
  • pH considerations: acceptable range 6.0–8.5; adjust only when justified.
• Interferences:
  • Colour, turbidity and light scattering (use turbidity corrections or colour‑correction tubes).
  • High oxygen demand, biodegradable nutrients, extreme pH, and salinity effects (special guidance for salt water in Annex D).
• Apparatus: Luminometer, thermostatic block, pH meter, oxygen probe (ISO 5814), pipettes and controlled-temperature baths.

Applications and users

ISO 11348-2:2007 is used for rapid screening of acute toxicity and is relevant to:

• Environmental testing laboratories and water quality monitoring agencies
• Wastewater treatment facilities and effluent compliance testing
• Environmental consultancies assessing leachates, extracts and sediment eluates
• Chemical manufacturers and registrants conducting ecotoxicity evaluation
• Research laboratories studying pollutant impacts on marine bacteria

The method supports regulatory and screening needs where a reliable, standardized luminescence inhibition assay is required.

Related standards

• ISO 11348-1: Method using freshly prepared bacteria
• ISO 11348-3: Method using freeze-dried bacteria
• ISO 5667-16: Guidance on biotesting of samples (sampling)
• ISO 5814: Dissolved oxygen measurement (electrochemical probe)

This concise summary helps practitioners select and apply ISO 11348-2:2007 for luminescent bacteria toxicity testing while understanding key procedural controls and common interferences.