Dealing with Mold

Molds (or moulds) can be a health hazard in buildings that are already built or under construction. Some are toxic and touching them or breathing in their spores can be harmful. It grows in areas with a large amount of moisture and should be taken seriously when found. So, today, let’s talk about dealing with mold. 

Molds are colourful and woolly. They can be almost any colour red, blue, brown, green, white, or black. They reproduce by releasing spores into the air, and more will grow where the spores land. It thrives on cellulose material that is wet, or water soaked. This includes drywall, ceiling tiles, wallpaper, particleboard, insulation, and plywood. It loves dark, moist places and can grow at room temperature, and can appear on damp materials in as little as 48 hours.  

You may be exposed to molds when you work in damp locations or water-damaged buildings. In a ventilation system, it may grow out of sight behind walls, under floors and carpets, and above ceilings.  

Safe work procedures

If you find moldy areas on a job, tell your supervisor. The company may arrange to have tests done. Samples must be analyzed to see whether it is dangerous, and, if toxic, must be removed. This process calls for special procedures, including protective equipment such as respirators, coveralls, and gloves. The company must train and equip workers for the job if removal is required.  

Follow these safe work procedures:  

• Clean up wet areas immediately and fix any leaks. Use ventilation to prevent moisture buildup. 
• Use mold-resistant products in damp areas when possible. 
• Wear a disposable respirator such as an N95 filter facepiece dust mask to remove small-scale mold. For larger projects or when using a hazardous product as a disinfectant, a supplied-air respirator may be required. Refer to the Safety Data Sheet (SDS) for the product.
• During cleanup, wear disposable gloves and safety glasses or goggles. 
• Wash your hands before eating, smoking, or drinking. 
• Restrict access to mold-contaminated areas. 
• Vacuuming may increase the spread of mold spores into the air. Use a central vacuum with an outside exhaust or a High Efficiency Particulate Air (HEPA) filter.  

Differences in building characteristics, climate, and occupancy mean no standard or strategy for mold remediation exists. The following provides a summary of generally accepted principles and processes:  

Identify and eliminate the moisture source: Mold remediation's first and most crucial step. It may involve major repairs or structural modifications, such as adding insulation or increasing ventilation with fans, as well as changing the behaviours and habits of occupants. Once the source of moisture is addressed, all materials and contents need to be dried immediately and thoroughly.  

Remediate heating, ventilation, and air conditioning (HVAC) systems: During structural remediation, heating, ventilation, and air conditioning (HVAC) systems may need to be deactivated or sealed off to prevent contamination and to limit the dispersal of mold spores and dust throughout the building. Contaminated HVAC systems need to be professionally remediated. 

Removal and remediation of contaminated contents: Contaminated and non-contaminated contents must be removed from affected areas before structural remediation. Contaminated contents should be discarded or thoroughly cleaned, using suitable methods, to prevent the introduction of significant mold spore reservoirs back into the remediated space. The cleaning methods generally follow the same guidelines as those for structural remediation, as outlined below.  

Removal of mold from structure: The physical removal of mold from the building is essential. Both live and dead mold and fragments contribute to mycotoxins and other mold products, which have been shown to retain their antigenic and toxic properties over extended periods.  

Cleaning strategies are based on the types of materials present and are classified as follows:   

• Porous materials with mold growth, such as ceiling tiles, wallpaper, drywall, and carpets, should be removed and discarded; they cannot be effectively cleaned.  
• Porous materials that are surface contaminated with dust or mold spores only, but do not contain mold growth, can be decontaminated by HEPA vacuuming if dry. If wet, materials should be professionally cleaned. Items that have been wet for extended periods are best discarded to prevent the further spread.
• Semi-porous materials with mold growth, such as wood, can be surface cleaned by scraping, scrubbing, and HEPA vacuuming. The integrity of structural components should be carefully examined to decide on a replacement if it is established that they have been physically compromised.  
• Non-porous materials, such as tile or glass, can be scrubbed and cleaned. 

Many guidelines recommend using soap or detergent and water to remove mold physically. Other guidelines recommend diluted bleach. The use of fungicides and antimicrobials is controversial due to concerns about the toxicity of the compounds, the questionable effectiveness in killing and preventing mold growth, and the concern that dead mold and fragments are still toxic/antigenic.  

Biocides/disinfectants are required in cases where contaminated water is present (e.g., sewage, soil, floodwater). Although encapsulation is sometimes used to cover moldy material with impenetrable paint or other sealants to prevent the escape of particles, there is little evidence to support this approach. It presents an ongoing risk to occupants if the paint/sealant is disturbed, and the mold is released back into the indoor environment.   

Disposal of contaminated material - Contaminated materials removed from the building should be sealed in 6 mL polyethylene bags to prevent spore dispersal. No additional special disposal requirements are recommended for mold-contaminated materials.   

Final cleaning, rebuilding, and clearance Once the building interior and contents have been dried. Mold-contaminated materials should be removed, and dust and visible traces of debris from the remediation process should be removed using damp wiping and a HEPA vacuum cleaner. Before containment teardown, clearance procedures should confirm that all water and moisture problems.