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 freshly prepared 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 (fresh water, brackish and sea water); - pore water; - single substances, diluted in water.