The Compounding Hazard
When an older building burns, the fire itself is not always the most enduring problem. Asbestos-containing materials — fibro sheeting, insulation, roofing felt, pipe lagging — may have been safely encapsulated in place for decades. Fire changes that equation immediately. Intense heat fragments asbestos-containing materials, releasing fibres that become airborne and can remain suspended in the atmosphere for hours or days after the flames are out.
Recent arson incidents, including a fire at a Hibiscus Coast café during Halloween weekend and a serious fire at a Palmerston North bar that opened in 1966, illustrate how quickly an arson event in an older building can become an asbestos contamination incident affecting the surrounding area. A nearby school closed following the Palmerston North fire after asbestos concerns were raised about smoke and debris from the burning structure.
What Happens to Asbestos in a Fire
Firefighting activities temporarily suppress airborne dust — the water knock-down is one of the most effective short-term suppressants available. But once the suppression stops, fibres in the debris can be re-released by wind, foot traffic, or continued demolition of the damaged structure. In heavily contaminated sites, fibre detection in soil and debris may persist for weeks after the incident.
The response protocol for asbestos-affected fire sites mirrors standard asbestos removal procedures: licensed specialists must conduct risk assessments, establish controlled environments with negative-pressure containment where required, use HEPA-filtered extraction equipment, and work in full personal protective equipment. Decontamination of the removal zone is required before the site can be re-entered by standard workers or the public.
The Economic Pressure Problem
Properly managed asbestos removal from a fire-damaged site is expensive. Licensed removal, controlled demolition, hazardous waste disposal, and site decontamination can collectively run into six figures for a medium-sized commercial building. This creates a perverse incentive structure: the financial burden of legitimate demolition and disposal may, in some cases, motivate building owners to take shortcuts. Authorities have recognised this and treat deliberate destruction of asbestos-containing structures as a major health and safety violation, with significant penalties for those prosecuted.
Implications for the Industry
For demolition contractors and asbestos removalists, the message from these incidents is practical. When taking on work in fire-damaged buildings built before 1990, assume asbestos is present until a licensed assessor has confirmed otherwise. Do not allow the urgency of a fire recovery situation to compress the due diligence process. The liability exposure from incomplete asbestos management in a fire-damaged building is substantial — and unlike smoke damage, it does not disappear when the building is cleaned up.
