Mold + Asbestos = Complex Projects

Aug 14, 2020

Oftentimes, environmental problems can involve more than one contaminant that needs to be addressed. A problem that often presents a two-fold issue is moisture intrusion. Whether the cause of the moisture is from flooding or condensation, it can cause significant damage to properties by damaging building materials. One consequence of such a problem is fungal growth. The secondary problem is that homes built before the late 1970s may have building materials that are asbestos-containing. The questions that often come up are which problem to correct first and which should be the highest priority between asbestos and mold.

How Does Mold Grow On Building Materials?

Fungal growth requires two key things for growth which are moisture and a nutrient source. The moisture can be supplied through a variety of ways. One common way is due to flooding which can be caused by plumbing problems, sump pump failure, cracked foundations, or many other sources. Another way moisture can become problematic is through condensation. The nutrient sources are often paper products, wood, or dust. Building materials may be composed of paper products or be reservoirs for dust. 

Common Asbestos Containing Materials Vulnerable to Fungal Growth

Common asbestos-containing materials that are paper-based are drywall, certain thermal system insulations, and felt. Drywall contains a paper facing which can be a suitable environment for mold growth if damp. This is a reason that damp drywall is often removed during mold remediation projects. In some cases, duct or pipe insulation can be damaged due to condensation which can grow on the accumulated dust or the cellulose of the material. Air cell pipe insulation and asbestos duct tape, for example, contain cellulose in their composition. Once mold growth appears and begins to compromise the material it may render them friable, thus making them more hazardous. Friability refers to the ability to render a material into dust with hand pressure when dry.

Which Has Higher Priority?

Once a suspect material becomes damaged and/or subject to mold remediation, it is highly recommended to have those materials tested for asbestos. Once the material has been confirmed to be asbestos-containing through laboratory testing, then the situation must shift from mold-focused to asbestos-focused. The reason is due to the inherent health hazard of asbestos vs mold. Mold health effects are commonly related to upper respiratory issues or allergic responses but are often not lethal. Asbestos exposure typically doesn’t cause immediate health effects, but over time can lead to mesothelioma, lung cancer, or asbestosis (which is a scarring of the lungs). Another reason why asbestos must be a priority is that asbestos is regulated at the federal level while mold is not. 


There are also state and municipal level requirements for asbestos inspections and abatement work. While mold licensing is mandated in a few states such as Florida and New York, every state often has a form of asbestos licensing for workers and inspectors. Mold remediation often follows industry standards such IICRC S520, while asbestos regulations are mandated by the EPA, OSHA, NIOSH, and other regulatory agencies. Even if one has a mold license as required by their state, they cannot remove asbestos-containing materials during mold remediation. 

In conclusion, if asbestos-containing materials will be impacted by mold remediation, then removal of the asbestos will always be the 1st priority and will require asbestos professionals to abate it. If you suspect that you have asbestos-containing materials that may have been affected by mold or upcoming remediation, we recommend having a third party company such as Indoor Science test the materials.