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Indoor Environment: Mold Abatement Procedures for UC San Diego Facilities Personnel

Last Updated: March 11, 2025 1:34:42 PM PDT
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Facilities Management and Housing, Dining & Hospitality personnel, follow these procedures when responding to work orders involving water damage and possible mold abatement.

Note: This information is intended exclusively for use by UC San Diego employees in university facilities.

1. Find and control the moisture source.

  • Control the moisture source. This is essential for stopping mold growth. Common sources of moisture contributing to mold growth include but are not limited to:
    • Flooding
    • Leaking plumbing fixtures, pipes, or appliances
    • Roof leaks
    • Water intrusion from outdoor irrigation
    • Unvented combustion appliances
    • High humidity
    • Condensation
    • Water collection dishes, such as refrigerator drip pans
  • Wear personal protective equipment and restrict access to the affected area if you know or suspect the water source is contaminated with sewage or chemical or biological pollutants.
    • Important: If flooding occurs in a lab or involves gray water (overflow from machines, pumps, aquariums, toilet bowls, etc.), call (858) 534-HELP (-4357). The Campus Police will dispatch an Environment, Health & Safety (EH&S) professional.
    • EH&S must give clearance before facilities personnel can work in the area.

2. Clean and dry water damage promptly.

  • Clean and dry water-damaged materials within 48 hours to prevent mold growth.
    • Maintain humidity below 60%.
    • Keep HVAC drip pans clean and flowing.
    • Do not use fans before determining that the water source is clean or sanitary.
  • Be alert for mold growth if materials have been wet for more than 48 hours. Mold growth may have occurred — but not always.
  • If you encounter or suspect mold growth during cleaning and drying activities, follow the steps below.

3. Take precautions while investigating.

  • Ensure personnel responding to work orders that may involve mold formation are trained to work safely.
    • Contact EH&S Occupational Health & Hygiene Services at ehsih@ucsd.edu to schedule basic mold prevention and abatement training for UC San Diego facilities personnel.
  • Take these safety precautions while investigating and evaluating mold and moisture problems:
    • Consider using an N-95 filtering facepiece, gloves, and eye protection.
    • Do not touch mold or moldy items with bare hands.
    • Do not get mold spores in your eyes.
    • Do not breathe in mold or mold spores.

4. Inform building occupants.

When indoor mold investigation or abatement work affects building occupants, address their concerns by doing the following:
  • Emphasize the health and safety of building occupants is a top priority.
  • Demonstrate that the occupants' concerns are understood and taken seriously.
  • Present clearly the current status of the investigation or remediation efforts.
  • Identify a person whom building occupants can contact directly to discuss questions and comments about the remediation activities.

5. Determine the size of the job.

  • Measure the affected area. The level of remediation procedures to follow depends on the size of the area involved. There are 4 levels of mold remediation.
  • Follow the appropriate procedure level for the size of the job:
  • Contact EH&S Occupational Health & Hygiene Services at ehsih@ucsd.edu if you need help classifying a mold remediation job.
  • Level 1
    • Use Level 1 procedures for areas 10 sq. ft. or less. Trained UC San Diego facilities staff must perform Level 1 work. Containment is not necessary.
    • Restrict entry to the work area to trained staff.
    • Use personal protective equipment.
    • Remove or clean contaminated materials:
      • Place items in a sealed waste bag.
      • Dispose of items as regular garbage.
    • Leave the area clean and visibly free of contamination and debris.
  • Level 2
    •  
    • Use Level 2 procedures for areas 10 to 30 sq. ft. Trained UC San Diego facilities staff must perform Level 2 work.
    • Restrict entry to the work area to trained staff.
    • Use personal protective equipment.
    • Cover the work area with plastic sheeting.
    • Remove or clean contaminated materials:
      • Use a HEPA vacuum cleaner.
      • Place items in a sealed waste bag.
      • Dispose of items as regular garbage.
    • Leave the area clean and visibly free of contamination and debris.
  • Level 3
    •  
    • Use Level 3 procedures for areas 30 to 100 sq. ft. Specialists trained in handling hazardous material must perform Level 3 work.
    • Consult with EH&S for Level 3 jobs.
      • Contact EH&S Occupational Health & Hygiene Services at ehsih@ucsd.edu.
    • Contract Level 3 work out to a professional mold remediation service.
      • Select a licensed service provider.
      • Ask for written scope of work, including removal method and use of biocides.
    • UC San Diego project managers, require the contractor to do the following:
      • Restrict entry to the work area to trained personnel.
      • Vacate building occupants from adjacent areas.
      • Use personal protective equipment.
      • Cover the work area with plastic sheeting.
      • Seal ventilation ducts and grills.
      • Remove or clean contaminated materials:
        • Use a HEPA vacuum cleaner.
        • Place items in a sealed waste bag.
        • Dispose of items as regular garbage.
      • Leave the area clean and visibly free of contamination and debris.
  • Level 4
    •  
    • Use Level 4 procedures for areas over 100 sq. ft. Specialists trained in handling hazardous material must perform Level 4 work.
    • Consult with EH&S for Level 4 jobs.
      • Contact EH&S Occupational Health & Hygiene Services at ehsih@ucsd.edu.
    • Contract Level 4 work out to a professional mold remediation service.
      • Select a licensed service provider.
      • Ask for written scope of work, including removal method and use of biocides.
    • UC San Diego project managers, require the contractor to do the following:
      • Restrict entry to the work area to trained personnel.
      • Vacate building occupants from adjacent areas.
      • Use personal protective equipment.
      • Seal ventilation ducts and grills.
      • Encapsulate the work area in plastic sheeting, ventilated with negative pressurization and a HEPA filter.
      • Use an airlocked, negative-pressure decontamination room.
      • Remove or clean contaminated materials:
        • Place items in a sealed waste bag.
        • Decontaminate the outside of the waste bags.
        • Dispose of items as regular garbage.
    • Contact EH&S Occupational Health & Hygiene Services at ehsih@ucsd.edu before authorizing occupancy.
    Note: The UC San Diego 4 levels of mold remediation are adapted from Guidelines on Assessment and Remediation of Fungi in Indoor Environments (PDF), New York City Department of Health.

Related information

Questions? Contact EH&S Occupational Health & Hygiene Services at ehsih@ucsd.edu.