There are at least four reasons a mold inspector should consider using Conditional Areas as the basis for the mold inspection report. First, Conditional Areas are recommended in IICRC S520- 2015 as the basis for mold remediation activities.(1) Second, assigning Conditional Areas forces the mold inspector to view a structure in greater detail. Third, the inspection strategy determines the sampling plan and the data-interpretation plan. Fourth, a stratified strategy allows the mold inspector to collect select samples as composites, reducing the cost of the inspection. The typical strategy used in mold inspections is referred to as Professional Judgment. A more sophisticated approach is to use a stratification strategy; separating interior spaces into discrete areas. One example of a stratification strategy that is recommended by AIHA is Similar Exposure Groups.

(2) Another example of a stratified strategy is the concept of Conditional Areas as defined by IICRC in S520-2015.(1) Conditional Areas, which typically have been applied to mold remediation plans, are defined as: • Condition 1: Areas not affected by a water intrusion incident [no restoration]; • Condition 2: Areas affected by contaminant spores settling onto surfaces [restoration]; • Condition 3: Areas affected by a water intrusion or elevated humidity [remediation]. The Condition of an interior space is typically assessed by combining the information gained from the visual inspection, incident history, occupant interview, and the sample results. However, it should be noted that assessing the Condition of a space may require the appropriate samples to be collected. For example, if the soft-surface items in a living room had simply been contaminated by settled spores (Condition 2), they could be HEPA-vacuumed and restored to service. However, if the living room had been affected by elevated humidity for an extended period those items may be Condition 3 (interior surfaces colonized with mold growth). Differentiating between these two Conditions may be possible based on either the visual inspection or incident history. When this approach does not provide the necessary guidance, a differential sampling method may be used to determine Condition. (3) First, S520-2015 recommends that “Condition (1, 2, or 3) … should be assessed, documented, and reported to the client”. In addition, Part 6 (Mitigation) of the IAQA/AIHA Body of Knowledge document states the mold inspector is responsible for “identifying appropriate responses and including them in the mitigation plan”.(4) Although the remediation contractor is responsible for implementing appropriate responses, the mold inspector is the party responsible for identifying the appropriate responses. If the mold inspector does not use Conditional Areas as the basis for the inspection report, then how can the remediation contractor use them as the basis for the remediation? Second, a significant advantage of using Conditional Areas as the basis for the inspection strategy is that it not only allows the structure to be assessed by area, it requires the mold inspector to assess each area separately. Both the IAQA Body of Knowledge and IICRC S520- 2015 state that an assessment should be performed when mold is present or suspected of being present. An assessment requires the assessor to differentiate between normal and contaminated indoor spaces. For example, the objectives of an assessment may include identifying (1) building-related contamination, (2) the condition of contents, and/or (3) occupant exposure potential; all of which are expected to vary with Condition. Stratifying interior spaces by Condition may focus the inspection, suggesting the objectives that are appropriate for each Conditional Area. Third, the inspection strategy not only provides the basis for the remediation plan; but it also provides the basis for the sampling plan and the data-interpretation plan. It is often not practical for the mold inspector to classify an entire structure as a single Condition, since Condition frequently varies from area to area. Viewing the structure as a whole is neither efficient for the IEP, the remediation contractor, nor the client. Basing the inspection on Conditional Areas forces the IEP to differentiate between normal and contaminated areas, and to identify the Condition of each area in the structure. Fourth, samples collected in the same Conditional Area may be combined and averaged. For example, if the three second-floor bedrooms are Condition 1, then a separate 5-minute airborne sample may be collected in each bedroom; or, a single composite sample may be collected – using a single cassette to collect a 5-minute sample in each bedroom (composite sample).

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