DIN ISO 16000-17:2010-06

Mould spores are widely distributed in the outdoor environment and, therefore, occur in varying concentrations also indoors. Growth of moulds in indoor environments, however, should be considered a hygienic problem because epidemiological studies have revealed that dampness and/or mould growth in homes and health problems affecting the occupants are closely related. Harmonized methods for sampling, detection and enumeration of moulds including guidelines for sampling strategies are important for comparative assessment of mould problems indoors. Sampling is carried out according to the method described in DIN ISO 16000-16 or -18. Agar plates (DG 18 agar and malt-extract agar or potato extrose agar) obtained from sampling by impaction are incubated directly at (25 +/- 3) °C and (36 +/- 2) °C. Filters obtained from sampling by filtration are re-suspended in saline solution (0,9 % NaCl) with 0,01 % Polysorbate 80. Decimal dilutions of the suspension are prepared and aliquots spread on DG 18 agar as well as on malt-extract agar or potato dextrose agar (indirect method). Agar plates are incubated at (25 +/- 3) °C. For special purposes plates can be incubated at (36 +/- 2) °C (e. g. thermotolerant Aspergillus spp.) or (45 +/- 2) °C (Aspergillus fumigatus). After incubation, mould colonies are identified and counted.