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 the anaerobic digestion of sewage sludge over periods of up to 3 days. The growth rate of anaerobic bacteria is much lower compared with that of aerobic microorganisms. For this reason, the test periods are longer for anaerobic methods than those used for aerobic bacteria. This method is applicable to substances, soluble or insoluble in water, including volatile chemicals (see Reference [1] in the Bibliography).