REMOVING MOLD

The goal of remediation is to remove or clean contaminated materials in a way that prevents the emission of mold spores and dust contaminated with fungi from leaving a work area and entering other occupied or non-abatement areas. At the same time, special care should be taken to protect the health of workers performing the abatement (remediation).

Ideally, any water intrusion occurrences should be stopped and cleaned immediately (within 24 to 48 hours). The more time that passes before clean up, drying, and removal of water damaged materials are addressed, the greater potential for mold contamination. In all situations, however, the underlying cause of water accumulation must be rectified or mold growth will recur.

Non-porous materials
(e.g., metals, glass, and hard plastics) and semi-porous (e.g., wood, and concrete) that are structurally sound and are visibly moldy can be cleaned and reused. Cleaning should be done using a detergent solution.

Porous materials such as ceiling tiles and insulation, and wallboards with more than a small area of contamination should be removed and discarded.

Porous materials (e.g., wallboard, and fabrics) that can be cleaned, can be reused, but should be discarded if possible. A professional restoration consultant should be contacted when restoring porous materials with more than a small area of fungal contamination. All materials to be reused should be dry and visibly free from mold. Routine visual inspections should be conducted to watch for reoccurrences.

Mold and Chlorine Bleach – Bleach is commonly used by homeowners despite being shown not to completely kill the treated microbes. Too often it damages the spores and may slow their growth but in a short time the bleach deactivates leaving you with clear mold and more water than you had initially which in time can add to the issues. It is common to see a yellowish tint where the treated mold was and then several months down the line there will be a fresh patch of whatever it was you bleached. It is best to use products that are known to be 100% effective and since we are trying to improve your indoor air quality, it matters to us that the products we use are all green, eco-friendly. Bleach is far from eco-friendly.

Five different levels
of abatement are described below. The size of the area impacted by mold contamination primarily determines the type of remediation. The sizing levels are based on professional judgment and practicality; currently there is not adequate data to relate the extent of contamination to frequency or severity of health effects.

Level I: Small Isolated Areas (10 sq. ft or less) – e.g., ceiling tiles, small areas on walls

  1. Small remediation jobs under 10 square feet can usually be conducted by a non-professional. Such persons should have knowledge of proper clean up methods, personal protection, and potential health hazards.
    For information from OSHA regarding Toxic and Hazardous Substances click here.
  2. An OSHA approved respiratory protection device such as the N95 disposable respirator, available at Home Depot, should be worn at all time while in the abatement area. Gloves and eye protection should be worn also.
  3. The work area should be unoccupied. Vacating people from spaces adjacent to the work area is not necessary but is recommended in the presence of infants (less than 12 months old), persons recovering from recent surgery, immune suppressed people, or people with chronic inflammatory lung diseases (e.g., asthma, hypersensitivity pneumonitis, and severe allergies).
  4. Containment of the work area is optional. However, dust suppression methods, such as misting (not soaking) or covering surfaces with plastic prior to remediation, are recommended.
  5. Contaminated materials that cannot be cleaned should be removed from the building in a sealed plastic bag. There are no special requirements for the disposal of moldy materials.
  6. The work area and areas used by remedial workers for egress should be cleaned with a damp cloth and/or mop and a detergent solution.
  7. All areas should be left dry and visibly free from contamination and debris.

Level II: Mid-Sized Isolated Areas (10 – 30 sq. ft.) e.g., individual wallboard panels.

  1. Mid-sized remediation jobs over 10 square feet can be conducted by a non-professional, however, careful assessment is recommended before beginning to help determine if a professional remediator would be better. Such persons should have knowledge of proper clean up methods, personal protection, and potential health hazards.
    For information from OSHA regarding Toxic and Hazardous Substances click here.
  2. An OSHA approved respiratory protection device such as the N95 disposable respirator, available at Home Depot, should be worn at all time while in the abatement area. Gloves and eye protection should be worn also.
  3. The work area should be unoccupied. Vacating people from spaces adjacent to the work area is not necessary but is recommended in the presence of infants (less than 12 months old), persons recovering from recent surgery, immune suppressed people, or people with chronic inflammatory lung diseases (e.g., asthma, hypersensitivity pneumonitis, and severe allergies).
  4. The work area should be covered with a plastic sheet(s) and sealed with tape before remediation, to contain dust/debris in the abatement area. Seal ventilation ducts/grills in the work area and areas directly adjacent with plastic sheeting. (Blue Painter’s Tape will usually not damage wall surfaces)
  5. Dust suppression methods, such as misting (not soaking) or covering surfaces with plastic prior to remediation, are recommended.
  6. Contaminated materials that cannot be cleaned should be removed from the building in sealed plastic bags. There are no special requirements for the disposal of moldy materials.
  7. The work area and areas used by remedial workers for egress should be HEPA vacuumed (a vacuum equipped with a High-Efficiency Particulate Air filter) and cleaned with a damp cloth and/or mop and a detergent solution.
  8. All areas should be left dry and visibly free from contamination and debris.

Level III: Large Isolated Areas (30 – 100 square feet)- e.g., several wallboard panels.

  1. A mold inspection professional with experience performing microbial investigations should be consulted prior to remediation activities to provide oversight for the project. The following procedures at a minimum are recommended:
  2. Personnel trained in the handling of hazardous materials and equipped with respiratory protection in accordance with the OSHA respiratory protection standard (29 CFR 1910.134, is recommended. Gloves and eye protection should be worn.
  3. The work area and areas directly adjacent should be covered with a plastic sheet(s) and taped before remediation, to contain dust/debris.
  4. Seal electrical switches and outlets and ventilation ducts/grills in the work area and areas directly adjacent with plastic sheeting. (Blue Painter’s Tape will usually not damage wall surfaces)
  5. The work area and areas directly adjacent should be unoccupied. Further vacating of people from spaces near the work area is recommended in the presence of infants (less than 12 months old), persons having undergone recent surgery, immune suppressed people, or people with chronic inflammatory lung diseases (e.g., asthma, hypersensitivity pneumonitis, and severe allergies).
  6. Dust suppression methods, such as misting (not soaking) or covering surfaces with plastic prior to remediation, are recommended.
  7. Contaminated materials that cannot be cleaned should be removed from the building in sealed plastic bags. There are no special requirements for the disposal of moldy materials.
  8. The work area and surrounding areas should be HEPA vacuumed and cleaned with a damp cloth and/or mop and a detergent solution.
  9. All areas should be left dry and visibly free from contamination and debris.
    If abatement procedures are expected to generate a lot of dust (e.g., abrasive cleaning of contaminated surfaces, demolition of plaster walls) or the visible concentration of the fungi is heavy (blanket coverage as opposed to patchy), then it is recommended that the remediation procedures for Level IV are followed.

Level IV: Extensive Contamination (greater than 100 contiguous square feet)

  1. A mold inspection professional with experience performing microbial investigations should be consulted prior to remediation activities to provide oversight for the project. The following procedures are recommended:
  2. Personnel trained in the handling of hazardous materials equipped with:Full-face respirators with high efficiency particulate air (HEPA) cartridges
    Disposable protective clothing covering both head and shoes
    Gloves
  3. Containment of the affected area:Complete isolation of work area from occupied spaces using plastic sheeting sealed with duct tape (including ventilation ducts/grills, fixtures, and any other openings)The use of an exhaust fan with a HEPA filter to generate negative pressurization
    Airlocks and decontamination room.
  4. Vacating people from spaces adjacent to the work area is not necessary but is recommended in the presence of infants (less than 12 months old), persons having undergone recent surgery, immune suppressed people, or people with chronic inflammatory lung diseases (e.g., asthma, hypersensitivity pneumonitis, and severe allergies).
  5. Contaminated materials that cannot be cleaned should be removed from the building in sealed plastic bags. The outside of the bags should be cleaned with a damp cloth and a detergent solution or HEPA vacuumed in the decontamination chamber prior to their transport to uncontaminated areas of the building. There are no special requirements for the disposal of moldy materials.
  6. The contained area and decontamination room should be HEPA vacuumed and cleaned with a damp cloth and/or mop with a detergent solution and be visibly clean prior to the removal of isolation barriers.
  7. Air monitoring should be conducted prior to occupancy to determine if the area is fit to reoccupy.

Level V: Remediation of HVAC Systems
5.1 A Small Isolated Area of Contamination (<10 square feet) in the HVAC System

  1. Remediation can be conducted by a non-professional. Such persons should have knowledge of proper clean up methods, personal protection, and potential health hazards.
    For information from OSHA regarding Toxic and Hazardous Substances click here.
  2. An OSHA approved respiratory protection device such as the N95 disposable respirator, available at Home Depot, should be worn at all time while in the abatement area. Gloves and eye protection should be worn also.
  3. The HVAC system should be shut down prior to any remedial activities.
  4. The work area should be covered with a plastic sheet(s) and sealed with tape before remediation, to contain dust/debris.
  5. Dust suppression methods, such as misting (not soaking) or covering surfaces with plastic prior to remediation, are recommended.
  6. Growth supporting materials that are contaminated, such as the paper on the insulation of interior lined ducts and filters, should be removed. Other contaminated materials that cannot be cleaned should be removed in sealed plastic bags. There are no special requirements for the disposal of moldy materials.
  7. The work area and areas immediately surrounding the work area should be HEPA vacuumed and cleaned with a damp cloth and/or mop and a detergent solution.
  8. All areas should be left dry and visibly free from contamination and debris.
  9. A variety of biocides are recommended by HVAC manufacturers for use with HVAC components, such as, cooling coils and condensation pans. HVAC manufacturers should be consulted for the products they recommend for use in their systems.

5.2 Areas of Contamination (>10 square feet) in the HVAC System

  1. A mold inspection professional with experience performing microbial investigations should be consulted prior to remediation activities to provide oversight for remediation projects involving more than a small isolated area in an HVAC system. The following procedures are recommended:
  2. Personnel trained in the handling of hazardous materials equipped with:Respiratory protection (e.g., N95 disposable respirator), in accordance with the OSHA respiratory protection standard (29 CFR 1910.134, is recommended.Gloves and eye protectionFull-face respirators with HEPA cartridges and disposable protective clothing covering both head and shoes should be worn if contamination is greater than 30 square feet.
  3. The HVAC system should be shut down prior to any remedial activities.
  4. Containment of the affected area:Complete isolation of work area from the other areas of the HVAC system using plastic
    sheeting sealed with duct tape.The use of an exhaust fan with a HEPA filter to generate negative pressurization.

    Airlocks and decontamination room if contamination is greater than 30 square feet.

  5. Growth supporting materials that are contaminated, such as the paper on the insulation of interior lined ducts and filters, should be removed. Other contaminated materials that cannot be cleaned should be removed in sealed plastic bags. When a decontamination chamber is present, the outside of the bags should be cleaned with a damp cloth and a detergent solution or HEPA vacuumed prior to their transport to uncontaminated areas of the building. There are no special requirements for the disposal of moldy materials.
  6. The contained area and decontamination room should be HEPA vacuumed and cleaned with a damp cloth and/or mop and a detergent solution prior to the removal of isolation barriers.
  7. All areas should be left dry and visibly free from contamination and debris.
  8. Air monitoring should be conducted prior to re-occupancy with the HVAC system in operation to determine if the area(s) served by the system are fit to reoccupy.
  9. A variety of biocides are recommended by HVAC manufacturers for use with HVAC components, such as, cooling coils and condensation pans. HVAC manufacturers should be consulted for the products they recommend for use in their systems.

Hazard Communication:
When fungal growth requiring large-scale remediation is found, the building owner, management, and/or employer should notify occupants in the affected area(s) of its presence. Notification should include a description of the remedial measures to be taken and a timetable for completion. Group meetings held before and after remediation with full disclosure of plans and results can be an effective communication mechanism. Individuals with persistent health problems that appear to be related to bioaerosol exposure should see their physicians for a referral to practitioners who are trained in occupational/environmental medicine or related specialties and are knowledgeable about these types of exposures. Individuals seeking medical attention should be provided with a copy of all inspection results and interpretation to give to their medical practitioners.

Summary:
In summary, the prompt remediation of contaminated material and infrastructure repair must be the primary response to fungal contamination in buildings. The simplest and most expedient remediation that properly and safely removes fungal growth from buildings should be used. In all situations, the underlying cause of water accumulation must be rectified or the fungal growth will recur. Emphasis should be placed on preventing contamination through proper building maintenance and prompt repair of water damaged areas.

Widespread contamination poses much larger problems that must be addressed on a case-by-case basis in consultation with a health and safety specialist. Effective communication with building occupants is an essential component of all remedial efforts. Individuals with persistent health problems should see their physicians for a referral to practitioners who are trained in occupational/environmental medicine or related specialties and are knowledgeable about these types of exposures.

Suggested Reading: (click to download free EPA booklets)

A Brief Guide to Mold, Moisture, and Your Home
This Guide provides information and guidance for homeowners and renters on how to clean up residential mold problems and how to prevent mold growth. [PDF] [HTML]

Una Breve Guía para el Moho, la Humedad y su Hogar
está disponible en el formato [PDF]

Mold Remediation in Schools and Commercial Buildings
This document presents guidelines for the remediation/cleanup of mold and moisture problems in schools and commercial buildings; these guidelines include measures designed to protect the health of building occupants and remediators. [PDF] [HTML]