During the remediation process, the level of contamination dictates the level of protection for the remediation workers. The levels of contamination are described as Levels I, II, and III. Each has specific requirements for worker safety. The levels are as follows:

Level I

Small Isolated Areas (10 sq. ft or less) for example, ceiling tiles, small areas on walls.

• Remediation can be conducted by the regular building staff as long as they are trained on proper clean-up methods, personal protection, and potential hazards. This training can be preformed as part of a program to comply with the requirements of OSHA Hazard Communication Standard ( 29 CFR 1910.1200).
• Respiratory protection (for example, N-95 disposable respirator) is recommended. Respirators must be used in accordance with the OSHA respiratory protection standard (29 CFR 1910.134). Gloves and eye protection should also be worn.
• The work area should be unoccupied. Removing people from spaces adjacent to the work area is not necessary, but is recommended for infants (less than 12 months old), persons recovering from recent surgery, immune-suppressed, or people with respiratory diseases.
• Containment of the work area is not necessary. However, misting and dust suppression is recommended.
• Contaminated materials that cannot be cleaned should be removed from the building in sealed impermeable plastic bags and disposed of as ordinary waste.
• The work area/areas used by workers for access/egress should be cleaned with a damp cloth or mop and a detergent.
• All areas should be left dry and visibly free of from contamination and debris.

Level II

Mid-sized Isolated Areas (10-30 sq. ft) – for example, individual wallboard panels.

• Remediation can be conducted the regular building staff as long as they are trained as for Level I. Respiratory protection, occupation of of the work and adjacent areas, and handling of contaminated materials are the same as for Level I.
• Surfaces in the work area that could become contaminated should be covered with sheet(s) of plastic that are secured in place. This should be done prior to any remediation process to prevent further contamination.
• Dust suppression methods, such as misting (not soaking) surface prior to remediation, are recommended.
• The work area/areas used by workers for access/egress should be HEPA vacuumed and cleaned with a damp cloth or mop and a detergent.
• As with Level I, all areas should be left dry and visibly free from contamination and debris.

Level III

Large Isolated Areas (30-100 sq. ft) – e.g., several wallboard panels

• Industrial hygienists or other environmental health and safety professionals with experience performing microbial investigations and/or mold remediation should be consulted prior to remediation activities to provide oversight for the project.
• It is recommended that personnel be trained in the handling of hazardous materials and equipped with respiratory protection (N-95 disposable respirator). Respirators must be used in accordance with OSHA respiratory protection standard(29 CFR 1910.134) Gloves and eye protection should also be worn.
• Surfaces in the work area and areas directly adjacent that could become decontaminated should be covered with a secured plastics sheet(s) before remediation to contain dust/debris and prevent further contamination.
• Seal ventilation ducts/grills in the work area and areas directly adjacent with plastic sheeting.
• The work area and areas directly adjacent should be unoccupied. Removing people from spaces adjacent to the work area is not necessary, but is recommended for infants (less than 12 month old), persons recovering from recent surgery, immune-suppressed or people with respiratory diseases.
• Dust suppression methods, such as misting (not soaking) surface prior to remediation, are recommended.
• Contaminated materials that cannot be cleaned should be removed from the building in sealed impermeable plastic bags and disposed of as ordinary waste.
• The work area/areas used by workers for access/egress should be HEPA vacuumed and cleaned with a damp cloth or mop and a detergent.
• All areas should be left dry and visibly free from contamination and debris.

Level IV

Extensive Contamination (greater than 100 contiguous sq. ft in an area).

• Personnel trained in handling of hazardous materials and equipped with:
• Full face respirators with HEPA cartridges
• Disposable protective clothing covering the entire body including the head, shoes and hands
• Containment of the affected area:
• Complete isolation of the work area from occupied spaces using plastic sheeting sealed with duct tape ( including ventilation duct/grills, fixtures, and other openings
• The use of an exhaust fan with a HEPA filter to generate negative pressurization, a decontamination room, and airlocks
• Contaminated materials that cannot be cleaned should be removed from the building in sealed impermeable plastic bags and disposed of as ordinary waste.
• The contained area and decontamination room should be HEPA vacuumed and cleaned with a damp cloth or mopped with a detergent solution and be visibly clean prior to the removal of any isolation barrier.

In conclusion, after the moisture source has been eliminated and the mold growth removed, the premises should be revisited and the reevaluated to ensure the mold growth and the remediation process was successful. The premises should be free of any moldy smells or visible growth.