Laboratory & testing
Mould in the Workplace: What Testing Can—and Cannot—Tell You
Understand when workplace mould sampling adds useful evidence, what an air result cannot prove, and how findings support moisture control and remediation.
A mould test cannot, by itself, establish that a workplace is safe. The World Health Organization’s 2009 Guidelines for Indoor Air Quality: Dampness and Mould explain that the evidence does not support a quantitative health-based threshold for acceptable indoor microbial contamination. For Jamaican facility managers, the useful question is what an assessment needs to establish about the building, rather than whether one sample produces a pass or fail.
Start with the building and the moisture problem
WHO’s guidance identifies visible mould, musty odours, condensation and previous water damage as indicators to investigate. Inspection, supported by appropriate measurements where needed, helps establish whether dampness and microbial growth are present. A history of leaks and the conditions observed on site belong alongside any laboratory findings.
When sampling can add useful evidence
The US Environmental Protection Agency’s Mold Testing or Sampling guidance, updated January 2026, says sampling is usually unnecessary when visible mould is already present. It also recognises that surface sampling may help assess whether an area has been adequately cleaned or remediated. Sampling therefore needs a defined purpose; it is not an automatic requirement for every concern.
The EPA recommends experienced professionals for sampling design, methods and interpretation. Before commissioning a test, ask what question it will answer, why the proposed method fits that question, and how its findings will inform the assessment. These are questions for the project team, not a universal sampling specification.
What an air result cannot prove
In its February 2025 guidance on mould, testing and remediation, the US National Institute for Occupational Safety and Health (NIOSH) advises against routine mould air sampling during building air-quality evaluations. Short sampling periods, including results that do not detect mould, may not represent actual exposure. Spore counts and culture results also do not capture the full range of exposures.
NIOSH cautions against interpreting short-term airborne mould concentrations as measures of health risk. Such a result cannot provide a general workplace safety certificate. US agency guidance is cited here for its technical explanation; it is not presented as Jamaican law.
Connect findings to corrective action
NIOSH’s remediation guidance includes correcting water entry and checking whether remedial measures remain effective. The management discussion should therefore address the moisture source and follow-up, as well as any sampling findings. A repeat test alone does not describe whether the underlying building problem has been corrected.
For offices and other commercial properties in Jamaica, ESL’s PureSpace commercial indoor-environment assessment brings together site-condition review, moisture and mould investigation, targeted sampling where appropriate, and reporting for management teams. The scope should reflect the particular building and concern.
For the wider assessment context, read when a workplace indoor-air-quality assessment may be appropriate.