Molds are a part of the natural environment. Outdoors, molds work to break down organic matter such as leaves and fallen trees. They reproduce by means of tiny spores that are present in outdoor and indoor air. Mold may begin growing indoors when spores land on surfaces that provide food, organic material, and moisture.
Mold has a distinctive ?musty' odor, but visually, active and inactive mold can be very different. Active mold in the early stages has hair-like filaments in webs, which develop a more bushy appearance as the bloom matures. Inactive mold is dry and powdery, and the surface layer can generally be readily brushed off the surface. Inactive mold can easily become active given the right environmental conditions. Mold can also cause staining of materials, which may be permanent even after the mold has been removed.
Most molds are not a health concern to healthy individuals. People with asthma or allergies may, however, be sensitive to molds and experience irritant or allergic reactions or worsening of asthma. Certain molds produce mycotoxins which, depending on the exposure level, can cause health effects. Both active and inactive molds can pose potential health hazards. Health effects from mold can be acute from short-term high exposures or chronic from long-term exposure to lower levels.
Assessing the Situation
Step 1: When interior mold is found, identify the source of the moisture problem, take action to eliminate it, and determine the extent of the water/mold damage. Note: When water damage occurs, quick action can prevent more extensive damage. Water should be cleaned up, and saturated building materials should be completely dried out within 24-48 hours.
Step 2: To protect your health and the health of the occupants of the building, employees must follow certain precautions when remediating mold contaminated areas. Based on the initial assessment, classify the area as:
Level A: water infiltration pre-mold condition
Level B: cleaning areas with mold contamination less than 2 square feet
Level C: cleaning areas with mold contamination of 2-10 square feet or removal of less than 10 square feet building materials
Level D: cleaning or removal of mold contamination between 10-30 square feet
Level E: mold contaminated area is greater than 30 square feet
Level A: Water infiltration pre-mold condition
- Water should be cleaned up, and saturated building materials should be completely dried out or discarded within 24-48 hours.
- If you know or suspect that the water is contaminated with sewage (black water), consult with your supervisor. Contract cleaning will likely be necessary.
- If the water is clean or grey water (dish, shower, sink, and laundry water), immediately wet-vacuum the area to remove as much water as possible.
- If carpet is wet, use the extractor vacuum.
- Increase ventilation and/or bring in dehumidifiers, fans, or heaters to expedite the drying. When the air outside is cold and dry, increase ventilation. If the air outside is warm and humid, dehumidifiers are necessary.
- Move file cabinets or other furniture that prevents thorough drying, so the floor underneath can be dried.
- Use GFCI protected circuits for all vacuums, fans, blowers, and all other electric-powered cleaning and drying equipment.
Building Materials Saturated by Water
- Dispose of ceiling tiles, fiberglass insulation, and other cellulose materials that are saturated.
- Bag and remove all saturated materials from the building within 12 hours.
- Sheetrock can remain in place if it can be thoroughly dried within 24 hours, there is no swelling, and the seams are intact; otherwise, remove it and allow the cavity to dry before replacing.
- Any areas where the structural integrity is in question must be immediately inspected by a qualified individual, contact your supervisor.
- Treat all wet electrical wiring, outlets, lighting, etc. as a shock hazard until inspected by a licensed electrician or building inspector.
- If you suspect that water is hidden in wall cavities, under flooring, behind paneling, or in other areas, investigate and open the areas up for drying as needed.
- Remove drapes and other removable cloth items for cleaning.
- Vacuum upholstered furniture to extract as much water as possible and dry further with ventilation and dehumidification.
Occupant Contents Saturated with Water or at Risk
- Assist occupants in moving equipment and other items that are wet out of the water and moving dry items out of any areas at risk for additional water damage.
- Refer occupants to procedures outlined in Preventing and Responding to Building Water Damage.
If the water was grey water, after removing the water and drying the areas, the surfaces should be wiped down with soap and water and a disinfectant.
Level B: Cleaning areas less than 2 square feet
- Wear gloves and goggles, if the cleaning chemical requires goggles; use of a N-95 particulate mask should not be necessary but can be worn at the option of the employee.
- For non-porous surfaces (e.g., metals, glass, plastic, tile) and semi-porous surfaces (e.g., wood, concrete), follow routine cleaning procedures using a detergent and water solution followed by a disinfectant. Follow all manufacturer's use specifications.
- For porous surfaces (e.g., wall board, ceiling tile), clean once; if contamination reoccurs, put in a work order to have it replaced.
- Removal of contaminated building material requires Level C or higher precautions.
- Dry the area thoroughly.
Level C: Cleaning areas of 2 - 10 square feet or removal of less than 10 square feet building materials
- Employees remediating Level C areas must be specifically trained in mold remediation and be in the respiratory protection program.
- Wear a cartridge respirator with P100 filters, gloves, and goggles. A Tyvek suit is also advisable for larger areas.
- The work area must be unoccupied until work is complete. Only trained personnel are authorized to enter the work area.
- Occupants of areas adjacent to the work area may remain, but must be informed of the work being done and those with medical conditions that could be aggravated be offered relocation.
- Care should be taken to prevent contamination of areas outside the work area. Containment and negative air may be necessary.
- Cover all surfaces with plastic to prevent contamination.
- Do not introduce large amounts of water into the work area. Excess water should be suctioned with a wet vacuum.
- Porous materials, such as carpeting, are extremely difficult to clean and should be disposed of.
- Dust suppression methods, such as light misting, should be used when tearing down wallpaper or removing carpeting.
- When cleaning mold from surfaces, use a detergent and water solution followed by a disinfectant. Follow all manufacturer's use specifications.
- Contaminated objects and building materials that cannot be cleaned should be placed in impermeable plastic bags, sealed, and disposed of as construction waste.
- The outside of the bags must be decontaminated prior to moving to other areas of the building.
- A final cleaning of the work area, including worker egress, should be done with detergent solution at project completion.
- All areas must be left dry and free from debris.
Level D: Cleaning or removal of mold contaminated in area is 10--30 square feet.
- Follow all procedures for Level C Areas.
- Wear a Tyvek suit.
- In areas with occupied surrounding areas, containment must be constructed and negative air established.
- HEPA vacuuming must be done in conjunction with the final cleaning procedures.
Level E: Mold contaminated area is greater than 30 square feet or involving HVAC systems.
For Level E areas, the services of an industrial hygienist will be contracted to develop work plans and oversee the project as well as conduct a final inspection upon project completion. A mold remediation contractor will perform the remediation services.
For further information or evaluation of specific areas, please contact the office of environmental health and safety.