In the professional fields of building restoration and microbial remediation, there are currently no set criteria regarding when to sample, how to sample, or what specific elements to sample for. It is a critical fact that no recognised industry standards or guidelines exist to provide defined acceptable levels for any specific bacteria or mould species on surfaces or in the air. This lack of consensus is especially prevalent in construction sites where properties have been partially stripped, leaving unhygienic interstitial spaces like roof spaces, wall cavities, and subfloor areas exposed.
Because there is no industry agreement on what constitutes an acceptable microbial level, these determinations are left to the consulting Indoor Environmental Professional (IEP) to make within the specific context of the project.
The Hypothesis-Driven Model
Experienced and certified microbial investigators only perform sampling when it is deemed actually required. Within a scientific framework, microbial sampling should only be conducted to prove or disprove a specific hypothesis. Examples of requirements for sampling include:
- Determining Abnormal Loadings: Evaluating if a surface has microbiological activity that is abnormal relative to what is reasonably expected.
- Exposure Risk Assessment: Identifying airborne exposure risks, though this is rarely required because the presence of water-damaged and contaminated materials itself constitutes a risk.
- Post-Remediation Verification (PRV): Determining if a surface has been cleaned to a satisfactory level to ensure all required works were completed successfully.
Elevated Risk Factors for Retaining an IEP
According to the ANSI/IICRC S500-2021 Standard, an IEP should be retained on Category 2 or 3 water damage projects when specific risk factors are present. These factors include:
- High-Risk Occupants: The presence of individuals who are considered high-risk.
- Public Health Concerns: Projects involving hospitals, childcare facilities, elderly care facilities, or public buildings.
- Health Risks: A likelihood of adverse health effects on occupants or workers.
- Contaminant Identification: A need to identify a suspected contaminant or to determine if the water actually contains contamination.
- Aerosolisation: Instances where contaminants are believed to have been aerosolised.
The Role and Skills of the IEP
An Indoor Environmental Professional is defined as an individual with the education, training, and experience to perform assessments of microbial ecology at a job site. Their specific skills include performing assessments of contaminated property, creating sampling strategies, maintaining a chain of custody, and interpreting laboratory data.
The IEP uses this data to establish a scope of work and to verify that the environment has returned to an acceptable, non-contaminated status, often referred to as Condition 1. The verification process includes visual inspection, odour detection, and environmental sampling to ensure the structure no longer poses a substantial risk from dermal, ingestion, or inhalation exposure.
Authoritative Oversight
At RIC Solutions, assessments are led by subject matter experts with more than thirty years of experience in specialist cleaning and decontamination. Our Managing Director, Jeremy Stamkos, is an industry veteran and an Accredited Instructor for the American Council for Accredited Certification (ACAC) microbial investigation and microbial remediation designations. He also contributes to the development of best practices and guidelines through service on various industry committees.