Remediation of Small-Scale Mould Growth (Less than 1 m²)
Remediation may be performed by regular building maintenance staff; however, only properly trained workers should perform mould abatement. Workers should be well informed about the hazards of mould abatement, and their training should include the use of personal protection and proper clean-up methods. Eating, drinking or smoking is prohibited in the work area.
- Occupants should not be present within the remediated area. The project authority (remediation supervisor) should consider whether occupants should be removed from the adjacent work areas. The determining factor is usually the presence of susceptible occupants, including, but not limited to, infants less than 12 months old,persons recovering from surgery, the elderly, and people with suppressed immune systems or chronic inflammatory lung diseases. Consultation with the facility operator is recommended.
- Workers must be medically fi t to work with potential mould exposure. Workers with a history of significant allergic disease (asthma, hay fever, hives, etc.) or other medical concerns should consult with an occupational physician to determine the health risks associated with mould removal and restoration activities. Mould abatement workers who risk infectious disease from unsanitary water sources (sewage, river floods, etc.) should consult with an occupational physician regarding appropriate immunization.
- Workers performing Level I mould remediation shall wear a half-face piece air-purifying respirator fitted with replaceable filters (N95 minimum) or a filtering face piece respirator (N95 minimum) and suitable eye protection. The selection, fitting, maintenance, and monitoring of the respirator shall meet the requirements of CSA Standard Z94.4, as amended. Workers shall be fit-tested with the assigned respirator, prior to the initial use and yearly thereafter. The seal of the respirator to the wearer’s face shall not be compromised by any facial hair. Filters shall be disposed of daily due to the potential growth of mould spores on damp filter media.
- Workers shall wear disposable coveralls and dust-impermeable gloves appropriate to the work being performed, and water-impermeable gloves when applying detergent or disinfectant. Workers can wear disposable boot covers or they should clean their boots before leaving the remediation area. Refer to the Material Safety Data Sheet (MSDS) for the selection of appropriate detergents, disinfectants, and gloves.
- Turn off HVAC systems and seal over all system openings (e.g., diffusers and return air openings) within or immediately adjacent to the work area.
- Movable non-porous items within the work area shall be cleaned with a HEPA vacuum, followed by a suitable cleaning solution, and then removed from the work site. Fixed non-porous items within the work area shall be first cleaned by vacuuming and wet wiping, and then sealed under polyethylene sheeting, taped in place during remediation work.
- Wherever possible, place a drop sheet below the mouldy materials to be removed.
- Do not use compressed air mechanical devices to clean up or remove contamination.
- Dust suppression methods should be used where possible, prior to disturbing mouldy materials. Tape a section of plastic sheeting or duct tape over the mouldy material, or, lightly mist the mouldy material with water. Do not dry sweep or dry whisk. Power tools fitted with dust collection bags will reduce airborne particulates.
- Remove any porous substrate materials (ceiling tiles, drywall, etc.) well beyond the immediate areas of visible contamination; the minimum recommended distance is 30 cm in all directions.
- After bulk removal, clean all exposed surfaces within the work area. Begin by cleaning with a HEPA vacuum and appropriate tools. Do not use any other type of vacuum. If a HEPA vacuum is not available, wet wiping is adequate for Level I work.
- Remove all waste created by the remediation work, including, but not limited to, building debris, disposable coveralls, respirator cartridges, and plastic sheeting. Seal all waste into 6 mil nominal disposal bags. Wet wipe or clean the bags with a HEPA vacuum and finally double-bag in a second clean 6 mil nominal bag or suitable sealed container.
- Clean all equipment used in the remediation work (e.g., vacuum cleaner, knives, saws) using a HEPA vacuum and by wet wiping. Equipment that cannot be readily cleaned (e.g. vacuum hose or wire brushes) shall be HEPA vacuumed and sealed in 6 mil polyethylene bags or suitable sealed container before removal from the work area.
- Dispose of the waste material in compliance with local, provincial, and federal regulations.
- Wash face and hands, and clean and maintain respirator after completion of mould abatement.
- Leave all areas dry and visibly free from contamination and debris, and ensure that surfaces are adequately dry prior to installation of new materials.