scope:

This part of ISO 13641 specifies a screening method for assessing the potential toxicity of substances, mixtures, surface waters, groundwaters and wastewaters, effluents, sludges, or other environmental samples by determining the production of biogas (carbon dioxide and methane) from muds, sediments and other anaerobic environments with low biomass concentration. The growth rate of anaerobic bacteria is much lower, compared with that of aerobic microorganisms. For this reason, the test periods in anaerobic methods are longer than in those with aerobic bacteria. The conditions of this test (for example amount of inoculum and substrate in the test bottles) were adopted to a defined test period over several days. The inoculum can be collected from anaerobic sediments or from large, or laboratory scale, anaerobic digesters. This method is applicable to materials, soluble or insoluble in water, including volatile chemicals (see Reference [1] in the Bibliography).