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Dampness and Mold in Indoor Workplaces

 Water damage, dampness, visible mold, or mold odor at a workplace is unhealthy. Molds are forms of fungi that are present indoors and outdoors. While most workers will not experience symptoms related to mold or dampness, some may develop new or worsening asthma, hay fever, or other health effects. The best ways to prevent health problems from mold are to find and fix the source of water that is allowing the mold grow, and quickly dry, clean, or remove damp or moldy materials.

What is mold and how does it grow indoors?

As a fungus, mold grows in damp locations inside or outside. Mold only needs moisture and a food source (organic material like wood, paper or fabric) to grow. Mold can be any color, including white, orange, green, brown or black. Indoor moisture leading to the growth of mold and other micro-organisms may come from flooding, leaks, high humidity, and steam. See the CDPH Frequently Asked Questions about Mold, What i​​s​ Mold for more information.

How do I know I am exposed to mold at work?

Sometimes mold is visible, but even if you cannot see any mold, you may notice a mildew or earthy smell. Mold may be found indoors on wet or damp walls, carpets, or ceilings, or behind wallpaper, as well as in heating, ventilation, and air conditioning (HVAC) systems. Mold produces seed-like spores that are small enough to travel through the air. You can breathe in spores, mold fragments, or mold products or have skin contact with mold.

Symptoms can indicate that you are exposed to mold at work. If you have symptoms, pay attention to when they occur. They may be work-related if they get worse when you are at work, and disappear or lessen at home or on weekends, or during vacations. Whether you have symptoms or not depends on your individual reaction to mold. See How can dampness and mold affect my health?​ below for more about symptoms.

How can dampness and mold affect my health?​

Dampness and mold exposure are associated with various allergic and non-allergic health effects. Mold in workplaces can cause new-onset asthma or make pre-existing asthma symptoms like coughing and wheezing worse and trigger asthma attacks.  Other symptoms include sneezing, runny nose, red, itchy eyes, skin rashes; cold and flu symptoms; and other respiratory symptoms. In rare cases, inflammatory lung disease (hypersensitivity pneumonitis) can develop from mold exposure at work. While most workers will have no reaction when exposed to mold, some workers with certain sensitivities and underlying health conditions are more susceptible to the effects of mold. Most mold-related illnesses can be treated by getting rid of the mold, moldy or damp materials, and source of moisture that allows mold to grow. Your doctor may also prescribe medication to control symptoms. See The National Institute for Occupational Safety and Health's (NIOSH) Workplace Mold page, the CDPH Air Quality Section's Mold page and the CDPH Frequently Asked Questions about Mold, Gener​​​​al Health to understand more about symptoms. 

​What do I do about mold and dampness in my workplace?​

There are no standards to say how much mold is hazardous to your health. There should not be visible mold growth, signs of dampness or visible water damage, or strong moldy odors in the workplace.

Report mold problems. If you see or smell mold, or if you or others are experiencing mold-related symptoms, report it so the problem can be investigated. You may need to tell your employer, supervisor, health and safety officer, union representative, or school board. Encourage co-workers who may have mold-related symptoms to report them. See if a particular office, floor, or area is affected.

California regulations protect workers. Even if your employer does not own the building, California Division of Occupational Safety and Health (Cal/OSHA) requires your employer to have an Injury and Illness Prevention Plan (IIPP) for your workplace. The plan must describe a procedure for employees to report hazards and how unsafe or unhealthy conditions will be corrected. Another regulation requires employers to correct uncontrolled indoor accumulation of water, like water leakage or condensation, that may cause mold. Cal/OSHA enforces these regulations.

  • Cal/OSHA can cite an employer for unsanitary conditions, including uncontrolled water accumulation, that may promote mold growth; see Safe Practices an​d Personal Protection, Sanitation. Employees who need information on workplace health and safety regulations, or who want to file a complaint, should call the nearest district office of Cal/OSHA at (510) 286-7000 or search online to find out which District Office covers your workplace. Your identity will be kept confidential. When making your complaint, you can reference the relevant regulations (see Cal/OSHA Standards​ below).

If you have symptoms see a doctor. Go to an occupational health clinic if you can. Bring this information to show your doctor and refer them to HESIS if there are further questions (see Resources​ below). If your illness is work-related, your doctor may recommend workplace accommodations, and you may be eligible for workers' compensation benefits. Make sure your doctor fills out a Doctor's First Report of Occupational Injury or Illness (DFR), a form that can open the workers' compensation claim (see Resources​ below).

Focus on fixing the problem, not testing for mold. A thorough investigation should reveal all sources of mold and moisture. CDPH does not recommend environmental sampling, since any mold that is present should be eliminated. Also, testing is not a reliable way to predict the health risks of dampness and mold. See the CDPH Frequently Asked Questions about Mold, Testin​​​g for Mold to understand more about why testing is not recommended.

Eliminate and control the source of moisture. As long as moisture is present the mold will return, so the source of the moisture must be eliminated and the building properly maintained.

Employers can hire a contractor to remove mold and damp materials. If a contractor (or other professional service provider) does the cleanup, it is best if they have experience cleaning up mold and that they follow the recommendations in the Environmental Protection Agency (EPA) guide Mold Remediation in Schools and Commercial Buildings, the guidelines of the American Conference of Governmental Industrial Hygienists (ACGIH), the Institute of Inspection, Cleaning and Restoration Certification (IICRC), or another institution's mold assessment and remediation guidance.

Clean up mold contamination. Mold and moldy or damp materials should be removed right away. No one with symptoms, or who has a health condition that makes them more sensitive to mold-related illness should participate in mold removal.

  • Ensure that workers who remove moldy materials use gloves, eye protection, coveralls, head and shoe covers, and properly fitted respirators. Use N-95 or more protective respirators (not dust masks) and follow the Cal/ OSHA Respiratory Protection Standard. Make sure mold removal workers are trained in dust control methods, use of personal protective equipment, and health risks.
  • Avoid using toxic chemicals. Fungicides and disinfectants are rarely appropriate since health effects are associated with both live and dead fungi and may endanger building occupants. Do not use ozone generators; ozone can harm your lungs, and when used at safe levels for humans, does not kill mold. Antimicrobial fogging or misting alone is not an effective way to remove mold and can leave a toxic residue that is harmful to humans.  Mold-resistant paints may contain toxic additives. No chemical can substitute for regular cleaning.
  • Scrub hard surfaces (tile, concrete, vinyl, undamaged wood) with ordinary household cleaning products. Bleach is not necessary or recommended. Use waterproof gloves.
  • Moldy porous materials (carpet, ceiling tile, wallboard, softened wood) usually require removal and replacement. For extensive removal jobs (greater than 30 square feet), HESIS recommends using a contractor specializing in this kind of work. There is no state license specifically for mold removal or cleanup.

Avoid exposure during mold cleanup. The highest exposure to mold often occurs during cleanup. You may need to temporarily leave work areas where cleanup is occurring, especially if you have symptoms or a medical condition that increases your risk of mold-related illnesses.  Open windows to increase ventilation during cleanup if possible.

Monitor symptoms after cleanup. If the symptoms persist after cleanup, they may not be related to mold, or the cleanup effort was unsuccessful. You and your doctor should explore other possible causes of illness. If there are other indoor air quality problems or the cleanup was not adequate, your employer may need professional assistance.

Cal/OSHA Standards

Regulations that help protect workers

  • Injury and Illness Prevention Program (Title 8, CCR 3203) - requires employers to develop and implement an effective written IIPP for identifying and correcting workplace hazards in a timely manner, and training workers on any hazards they might face on the job.

  • Respiratory Protection (Title 8, CCR 5144) - requires employers to provide respirators when such equipment is necessary to protect the health of the employee.

For additional standards, you can search the official text of all Cal/OSHA standards.

Resourc​e​s

Where to get h​elp

  • Cal/OSHA: Cal/OSHA investigates workers' complaints and answers questions about workplace health and safety issues. Find a Cal/OSHA district enforcement office near you or call (510) 286-7000.
  •  Cal/OSHA Consultation Service provides free assistance to employers to help them improve health and safety and comply with Cal/OSHA regulations. E-Mail: InfoCons@dir.ca.gov or call 1-800-963-9424
  • The NIOSH Health Hazard Evaluation (HHE) program is a free service that evaluates U.S. workplaces for health hazards. Employees, employers, and union officials can request an HHE if they suspect workplace exposures or conditions are harming employees' health. HHEs recommend ways to reduce health hazards and prevent work-related illness and injury.
  • Workers Compensation: For questions about filing a workers compensation claim see the Department of Industrial Relations Information and Assistance Unit  or call the Division of Workers Compensation (DWC) Information Services Center at 1-800-736-7401.
  • Finding an occupational physician: To find a doctor who specializes in work-related injury and illness, search for “occupational medicine providers, your city name, CA" in your preferred internet browser. If you are filing a Workers Compensation claim, go to the contracted clinic. See Division of Workers Compensation, Medical Care for more information.
  • Or contact a University of California Occupational Medicine Clinic in your area.

    • Irvine (949) 824-8685
    • San Francisco Bay Area (415) 885-7580, ext. #1
    • Sacramento/Davis Area (530) 752-6051
    • San Diego (619) 471-9210 or (858) 657-1600

 Publications

  • Environmental Protection Agency (EPA) guide. Mold Remediation in Schools and Commercial Buildings presents guidelines for the remediation/cleanup of mold and moisture problems in schools and commercial buildings.
  • Indoor Air Quality Tools for Schools is a kit developed by the EPA to help with investigation of indoor air issues at schools.  
  • Listings of indoor air quality consultants can be obtained from the American Industrial Hygiene Association. Select the specialty as “mold," the service type as “commercial" or “residential" and the postal code for the workplace to obtain a list of consultants from the Consultants Directory.

​For further questions not addressed by the above resources:

Hazard Evaluation System and Information Service (HESIS) answers questions about chemicals and other workplace hazards.
www.cdph.ca.gov/hesis  Email: HESIS@cdph.ca.gov​
(510) 620-5817 • (866) 282-5516 (toll-free in California)​

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