Protecting Workers from Workplace Mold: The Fungus is Among Us
By Safety Management Group
Most of the hazards encountered on a construction site are large and fairly obvious. Whether it’s the inherent danger of working with certain power tools, the potential for a fall, or the possibility of an electric shock, the visibility or familiarity with these hazards helps to keep workers’ attention focused on avoiding them.
Other hazards are far more insidious, and one of the most misunderstood is a very simple living organism. Molds fall into a category of fungi that perform important tasks in natural environments such as breaking fallen leaves down into natural fertilizer. They also have useful roles in our lives, such as turning milk into cheese. But the wrong types of mold spores in the wrong places can lead to a host of problems for workers and those who occupy structures.
From a sensory standpoint, molds are unpleasant. They make surfaces appear to be unclean, and they often give off obnoxious odors. However, the problems with the sensory issues are minor when compared to the effects upon health. Most of us are familiar with people who are allergic to molds, and molds can trigger asthma attacks. An even bigger concern is the types of mold that can produce what are known as mycotoxins. While scientists have reached few definitive conclusions about the effect of mycotoxins on the human body, there has been growing suspicion that they can trigger many serious medical conditions. Amazingly, these tiny organisms can also compromise the structural integrity of wood-framed buildings.
There are more than 100,000 species of mold throughout the world, and this article cannot possibly provide a detailed examination of each. Instead, we’ll focus on practical strategies for avoiding the development of mold, and the steps workers should take to remediate mold they encounter on the jobsite.
How mold occurs
Molds may pop up almost anywhere. The simple fact is that they can grow anywhere that they find sufficient moisture, oxygen, and food. Living molds give off microscopic seeds call spores that constantly float around us. If those spores land in a damp area that provides the right kind of food — depending upon the species, that can mean anything from wood, to paper, to household dust — they’ll begin to grow. Molds will give off more spores that will land nearby and continue the cycle. That’s how mold appears to spread.
You may not be able to eliminate mold spores in their air, but you can create an unwelcome environment that will discourage them from growing and reproducing. Since molds thrive on moisture, minimizing water and humidity is a first step. Improving air circulation and exposure to light will also reduce moisture.
A key element of mold prevention is addressing moisture issues quickly. Any type of water leak, flooding, or condensation should be addressed and cleaned promptly, ideally within a day or two. In addition to cleaning up areas that are wet, it’s important to identify and repair the source of the moisture. Take steps to reduce the indoor relative humidity to 60 percent or less, and properly ventilate any devices that produce moisture.
Remediation starts with a plan
There is more to remediating occurrences of mold than simply cleaning it up. First, you need to be sure that workers and other users of the space are not needlessly exposed to airborne mold created during the cleanup process. Second, you must be certain to remove all visible mold and any damage that was created. Finally, you need to take steps to ensure that an underlying problem does not lead to a recurrence of the mold.
That’s why the first step should be a plan. Simply handing a worker a mop and a scrub brush probably won’t lead to an effective resolution. In cases of widespread mold, your best approach may be to bring in a specialized contractor that has extensive experience with mold remediation.
You plan should spell out the specific work that is to be performed, the equipment and chemicals the workers will use (including the appropriate Personal Protective Equipment), procedures to be followed, how workers should dispose of contaminated materials, steps to be taken to prevent a recurrence, and how the area will be monitored in the future.
Protecting workers and occupants
Whenever possible, work should be scheduled when areas are unoccupied. If that isn’t practical, the plan must include strategies for limiting exposure to mold spores, dust, and other potential contaminants. There is no single solution that is best. The choice of strategies will depend upon the nature of the structure and the mold contamination, as well as available ventilation.
Workers should wear the correct type of PPE for the situation. At a minimum, that may include rubber gloves, eye protection, and a respirator. Depending upon the nature and extent of the contamination, other protective gear such as rubber boots or hazmat suits may be needed. The plan should also spell out how workers will be decontaminated at the end of work, if needed.
In addition, employers need to know if a particular worker may have a mold allergy, condition such as asthma, or an impaired immune system, so the worker’s health may be protected. In some cases, it may be best to choose another worker for the task.
Using chemicals in remediation
Often the first response to a mold problem is to apply a biocide such as chlorine bleach to the affected area. However, biocides are generally not the best solution. First, even after most molds have been killed, they still have the potential to create allergic or other responses in people with sensitivities. In addition, even a highly effective biocide may still leave some mold spores behind, and if the underlying conditions have not been protected, the mold will grow again. Biocides can also have negative health impacts, especially on people with suppressed immune systems. In larger amounts, they can even be toxic.
Because molds are a form of fungus, you may be tempted to use a fungicide. However, most fungicides are intended for outdoor applications, and using them indoors can create a toxic situation.
Remediation and cleanup procedures
Before beginning the actual cleanup, make sure that any surfaces that could be contaminated by airborne mold and dust have been securely covered with plastic. It’s usually also a good idea to seal ventilation ducts and grilles before work begins, unless they will provide the primary source of ventilation for the work.
The specific methods for cleanup will vary based upon the nature and extent of the contamination. For example, wet vacuums can be used to remove water from carpets and hard surfaces. Nonporous surfaces can be scrubbed with detergent and water or with a wet wipe. Once the remediation work has been completed and everything has dried, it’s a good idea to use a HEPA (high-efficiency particulate air) vacuum to remove any dust from the affected area, and then clean all surfaces with a damp cloth or detergent solution.
Disposal of contaminated materials
Any porous materials that show evidence of mold growth or water damage should be discarded, because molds may form deep inside them. Materials that can’t be salvaged should be kept in closed containers or sealed bags. Larger items with significant continuation may need to be wrapped in plastic before disposal. Typically, they can be disposed with other construction waste.
Preventing future contamination
Once the area is completely dry, and there is no visual evidence of mold (or any moldy smell), and you’ve solved whatever caused the mold problem in the first place, the area is ready to be occupied again.
It’s a good idea to re-inspect the area periodically to ensure that mold and odors have not returned. Some people recommend airborne testing, but that can be an expensive and complicated process. In addition, there are few clear standards on airborne mold. If you’re giving thought to some type of regular testing program, consult with an industrial safety professional or industrial hygienist about whether it’s the right choice for you. If so, that professional can help you develop a program that effectively meets your needs.
One simple step that can help you stay ahead of mold is to get better at managing the humidity in the affected areas. An inexpensive humidity gauge will let you know if the indoor humidity is getting too high. You can also have a humidistat added to your HVAC system to automatically make adjustments when humidity levels rise above a specified level.