ISO 16000-17:2008

Overview

ISO 16000-17:2008, "Indoor air - Part 17: Detection and enumeration of moulds - Culture-based method", specifies a standardized culture-based procedure for detecting and counting moulds (filamentous fungi) from indoor air or material samples. The method applies after sampling by filtration (ISO 16000‑16) or impaction (ISO 16000‑18) and is also suitable for cultivation from material suspensions or direct plating. The standard supports reproducible enumeration (expressed as colony forming units, CFU) and identification of mould colonies for indoor air quality assessment.

Key topics and technical requirements

• Sampling compatibility: Works with samples collected by filtration (filters) or impaction (agar impactor plates).
• Sample processing: Filters are resuspended in saline (0.9% NaCl) with 0.01% polysorbate 80 (Tween), followed by decimal dilutions and plating (indirect method). Direct impaction plates are incubated without resuspension.
• Culture media: Recommends DG18 (dichloran 18% glycerol agar) and either malt-extract agar or potato dextrose agar to recover a broad spectrum of indoor moulds. DG18 is used for its reduced water activity to support mould detection.
• Incubation conditions: Standard incubation at (25 ± 3) °C. For targeted recovery of thermotolerant species, incubation at (36 ± 2) °C or (45 ± 2) °C (e.g., Aspergillus fumigatus) is described.
• Examination and enumeration: After incubation, colonies are identified to the extent required and counted; results are calculated and reported as CFU per sampled volume or per unit area.
• Equipment and quality: Specifies standard microbiological apparatus (vibration‑free incubators, safety cabinet, pH meter, autoclave) and use of validated reagents and media.
• Safety: The standard includes a warning that hazardous materials and procedures may be involved; users must follow appropriate laboratory safety and regulatory requirements.

Applications and users

• Indoor air quality (IAQ) assessments - building inspectors, IAQ consultants, occupational hygienists.
• Microbiology and environmental laboratories - routine monitoring, diagnostic testing, and comparative analyses.
• Remediation verification - confirm effectiveness of mould remediation or moisture control measures.
• Research and epidemiology - studies linking indoor dampness/mould to health outcomes.
• Regulatory and legal contexts - standardized evidence for compliance, risk assessment, or dispute resolution.

Keywords: ISO 16000-17:2008, indoor air, mould detection, culture-based method, DG18 agar, sampling by filtration, sampling by impaction, CFU, mould enumeration, indoor air quality.

Related standards

• ISO 16000-16 - Detection and enumeration of moulds - Sampling by filtration.
• ISO 16000-18 - Detection and enumeration of moulds - Sampling by impaction.
• ISO 8199 - Guidance on enumeration of micro-organisms by culture (referenced for culturing practice).