After a Flood, Cleanup Safety Means Knowing—and Dealing With—Mold

Mark Tartaglia

Expert intel on the biohazards found after a flooding disaster, advice on how to deal with them, and six tips for safely cleaning up when there’s mold.

Water is an essential element for all living things. It can also be a force for massive destruction associated with many natural disasters, including hurricanes, tsunamis, floods, mudslides, and severe rainstorms. Even tornados, known for the damage they cause due to high winds, often have heavy rain associated with them.

According to the National Oceanic and Atmospheric Administration (NOAA), the total cost of U.S. billion-dollar disasters over the last five years—2017–2021—is $742.1 billion, with a five-year annual cost average of $148.4 billion. Furthermore, the U.S. experienced 20 separate billion-dollar weather and climate disasters in 2021, putting that year in second place for the most disasters in a calendar year, behind the record 22 separate billion-dollar events in 2020. Then, 2021 brought 14 water-related disaster events with billion-dollar price tags, including four hurricanes, two floods, and eight severe weather events. And there are many smaller dollar events taking place every year that negatively impact countless numbers of victims.

flood safety cleanup shows volunteer working in house
A Greyshirt mucks out a home that flooded in Maryland.

For those who have experienced floods, the hazards they leave in their wake can be many. Not least among them is often mold. Typically, mold cleanup involves either maintenance or remediation, depending on the scope of the problem. Maintenance involves small areas of contamination (less than 30 square feet). Remediation is assumed to be large-scale, and a specialized contractor should be used to complete the work. 

Whether you’re a homeowner attempting to recover on your own, or a disaster response volunteer on the ground responding to a flood, there are tips for flood cleanup safety.

Biohazards Bloom After A Disaster

Post-disaster cleanup efforts present many hazards to victims, emergency responders, and anyone performing cleanup activities. In addition to physical hazards, such as those associated with floodwaters, downed trees, and electrical outages, releases of chemicals or sewage may contaminate land, water, and buildings.

Among the insidious biological hazards to be cautious about after a flood, and during flood cleanup, is the extremely high potential for mold growth in structures, carpeting, furniture, and other materials that have become wet due to the heavy rains or flooding. Capable of producing toxins, volatile organic compounds, and other metabolites, molds grow in colonies and are disseminated as spores by both wind and water. While not all molds or fungi are harmful to people, exposure to those that are can cause asthma, various allergic reactions, and contact dermatitis.

Understanding Mold

Molds and other fungi are pervasive in the outdoor environment where they usually are found in much higher airborne concentrations than indoor air. They typically enter the indoor environment through openings—through windows, doors, or cracks, for example—and are carried in on the surface of objects brought indoors, including people. Because molds require moisture and organic substrate matter to grow and propagate, disasters where there has been extensive flooding provide prime conditions for undesirable growth. Add to that the fact that mold flourishes at temperatures of 60 F to 80 F and most water-related disaster zones in the U.S. are prime for mold growth.

flood cleanup safety on display as volunteers in PPE clean up drywall
Volunteers take down drywall damaged in a flood.

When these conditions—high humidity and warm temperatures—exist after a disaster, those performing flood cleanup and recovery need to beware. Anyone performing cleanup or remediation activities must be able to recognize the actual or potential presence of mold and take precautions to protect themself from it. 

Visible mold growth—including dark staining on walls or carpeting—as well as strong mold odors, such as a damp, musty smell, are all signs that mold is present.

6 Tips for Practicing Mold and Flood Cleanup Safety 

While the Environmental Protection Agency and Occupational Safety and Health Administration in the U.S. don’t have specific standards or regulations concerning mold and fungal exposure in outdoor or indoor environments, many states are developing regulations or have passed legislation applicable to fungal growth in indoor environments. Regardless of where you live, anyone working in a flooded home, cleaning up where mold is present, or performing mold remediation work should follow some basic precautions.

1: Isolate the Cleanup Area

Create a zone around the cleanup area and prevent anyone not wearing PPE from entering.

2: Protect the Lungs

Avoid breathing in mold spores. When potential mold-contaminated material is present, put on an N95 respirator, and change it whenever it gets dirty. Always wear appropriate PPE.  

3: Prevent Skin Contact With Mold

Avoid touching mold with your bare hands or skin. If you touch mold with a glove, change the gloves. Beware of transfer of mold to the skin. 

4: Don’t Disturb the Spores

Take care not to cause mold or mold spores to be dispersed into the air where they can be inhaled by building occupants. Be cautious when checking behind wallpaper and other wall coverings to avoid the potential release of spores.

Don’t run an HVAC system if it’s contaminated with mold: If you know or suspect that an HVAC system or air conditioner is contaminated with mold, don’t use it. Don’t use an air mover where dry materials can be disseminated.

Don’t dry-scrape mold contamination; use a high-efficiency particulate air (HEPA) vacuum instead.

5: Bag and Seal Contaminated Materials

During cleanup, cautiously remove, bag, seal, and dispose of damaged materials, including drywall, carpeting, furniture and similar contaminated materials. 

6: Use Soap or Bleach Solution for Mold, Not Paint

Out of sight is not out of mind: Do not paint over mold. If cleaning surfaces, wet-wipe the mold with soap and water or a bleach solution of no more than 1 cup (8 ounces) household laundry bleach per 1 gallon of water to kill mold on surfaces.

The Best Personal Protective Equipment (PPE) to Wear When Cleaning Up After a Flood

Anyone performing post-disaster cleanup activities can be exposed to a variety of potential biological, chemical, and physical hazards. Whether you’re a homeowner cleaning up after a flood or a Team Rubicon volunteer performing muck outs for those affected by a disaster, choosing the right PPE is important to flood cleanup safety, and to ensuring the health and safety of the people doing the work. 

A hazard assessment should be conducted specific to the activities associated with the work. In post-disaster scenarios, consideration should be given to possible inhalation of or skin contact with toxins, potential exposure to fire or flame, electric shock risks (such as from exposed wiring), chances of cuts or abrasion, the possibility of falling objects, unstable walls or surfaces, and trip-and-fall hazards, for example.

volunteer in PPE practices flood cleanup safety as they remove debris from home
Cleaning up from flooding Maryland. Photo by Robert Rivera.

Based on the hazards identified in the assessment and the conditions for exposure to workers, exposure controls should be established according to the hierarchy of controls—engineering controls, such as ventilating fans, safe work practices, and PPE. 

When it comes to flood cleanup safety, the need for PPE is virtually guaranteed. If the potential exists for the inhalation of mold spores, an N95 respirator or half-mask respirator with particulate filters should be worn and changed frequently, whenever it becomes dirty. Wearing a protective overgarment, such as a Tyvek coverall, to protect the individual against contact contamination is often essential. Anyone who does don Tyvek should also remove the overgarment at the worksite to avoid spreading contaminants to vehicles and other locations. And, in all cases, anyone doing muck outs or disaster recovery should always wear protective gloves and eyewear.

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