ISO 11348 describes three methods for determining the inhibition of the luminescence emitted by the marine bacterium Vibrio fischeri (NRRL B-11177). This part of ISO 11348 specifies a method using freeze-dried bacteria.

This method is applicable to:
- waste water;
- aqueous extracts and leachates;
- fresh water (surface and ground water);
- sea and brackish water;
- eluates of sediment (freshwater, brackish and sea water);
- pore water;
- single substances, diluted in water.