An Evaluation Procedure for Post Fire Re-occupancy in Commercial & Industrial Structures

1259 

Professional Poster 

A DiMaggio¹

¹Chubb Global Risk Advisors, Chicago, IL

Anthony DiMaggio, CIH  
Chubb Global Risk Advisors

Small scale fire events seldom occur in commercial and industrial structures. However, when they do occur, these events can drastically disrupt production and create employee health concerns. Based on an actual flash fire/explosion event at an industrial building, this poster presents a post fire procedure to evaluate the indoor environment for potential hazardous conditions which could impact employee health and outlines a methodology for re-occupancy. Overall, the methodology described in this poster is intended to educate the audience on a recommended approach to evaluating small scale fire events and describe a re-occupancy procedure.

After a fire event occurs in a commercial or industrial building and first responders leave, management is left to deal with the aftermath. Depending on the level of impact to the building, management needs to make the decision to allow or not allow employees back into the building. The decision should be based on the best interests of employee safety and health. The fire/explosion event associated with this poster occurred in an industrial building during normal working hours with employees occupying the building. The source of the event was located within a compressor room. Physical damage was limited to the compressor room and adjacent loading dock area. The facility sprinkler system activated, and distinguished the fire. Visible fire damage was limited to components of the compressor room. Security video captured smoke and debris migration to employee occupied areas. Company management obtained our services to: a) initially evaluate the indoor environment for potential hazardous conditions which could impact employee health; b) provide an opinion regarding the use of personal protective equipment (PPE) for remediation contractors; and c) evaluate re-occupancy for a limited amount of production and office employees.

Once we were able to visualize the extent of the impacted areas and the current state of the situation, an initial onsite evaluation was conducted. The onsite assessment included 1) a visual observation of the impacted areas; 2) development of a sampling plan; 3) bulk sampling of damaged building materials suspected to contain asbestos; 4) surface contamination sampling (PCBs, fire-related particulate [char, soot, ash]) in heavily impacted areas vs. nonimpacted areas; 5) direct-reading and laboratory air sampling methods (particulates, VOCs); and 6) determination of moisture content to building materials affected by the sprinkler system. The poster will include a table describing: a) the instrumentation / sampling methods used; b) contaminants of concern; c) published exposure limits from applicable organizations; and d) sampling method limitations. The table will also include other sampling methodologies and associated exposure limits not employed during this evaluation, but could be applicable to other types of fire events and/or could have been used to supplement this evaluation. We will describe how PM2.5 limits discussed in the recent state of California emergency regulation to protect workers from wildfire smoke can be used to screen indoor air environments for potential levels of airborne fire-related particulates.

The analytical results obtained from the initial onsite assessment supported our opinion of allowing employees to re-occupy the building and continue normal work activities. No PCBs were detected in the residual compressor oil. Impacted building materials did not contain asbestos nor contain sufficient moisture capable of supporting biological growth. Settled particulate was concentrated near the impacted areas and other employee nonimpacted occupied areas (i.e. offices, warehouse, and production floor) showed results of none detected to below LOD. Fire-related particulates results helped determine the degree of cleaning levels employed by the remediation contractor.Fire-related particulate analyses are not health based in nature and this limitation will be discussed in the poster. Overall, the analytical results did not support the need for additional analysis of fire-related particulates/by-products (i.e. metals, PAHs, dioxins, etc.). Other than the compressor room, no odors atypical of normal office environments or the production operation were observed. Total airborne VOC concentrations were also low. The results also supported the recommendation of containing the heavily impacted areas and providing dermal and respiratory PPE during remediation efforts of those areas.

Having an industrial hygiene professional conduct a post fire indoor environmental quality evaluation will help management make the critical decision of allowing employees to re-occupy a building safely. Information provided to management should be health based and presented in a way which is easily communicated and understood by employees and stake holders. Employing the evaluation procedures described in this poster can help ensure health-based information was considered before re-occupancy. A good post fire indoor environmental quality evaluation requires: a) sound understanding of specific physical information related to the fire event; b) development of reliable health-based sampling plans and methodology; and c) professional opinion regarding re-occupancy, remediation, and exposure control.

Indoor Environmental Quality/Indoor Air Quality

Consulting

Exposure Assessment Strategies