The New York City Department of Health developed guidelines for mold removal that have become very useful for professional mold remediators and homeowners alike. There are five different levels of mold abatement, and the size of the infestation determines the type of remediation.The department recommends that the simplest and quickest remediation that properly and safely removes mold from your home should be used. Structurally sound items made of concrete, glass, hard plastic, metal, and some wood can be cleaned using a detergent solution and reused. Porous materials such as ceiling tiles and insulation, and wallboards with more than a small area of contamination (10 square feet) should be removed and discarded. Although some fabrics that can be cleaned may be reused, it’s better just to throw them away. Routine inspections should always be performed to confirm whether the remediation process has been effective.
The average home owner shouldn’t attempt to clean a mold infestation higher than a Level I without the help of a health and safety professional who has experience in mold remediation procedures. Obtain a written contract that includes estimated completion dates for various stages of the work, and have the contractor develop a written action plan within five business days of accepting the job.
The following five levels of mold abatement summarized here are discussed in greater detail at the New York City Department of Health’s Web site:
Level I (10 sq ft or less)
This small infestation would most likely involve a ceiling tile or small section of wallboard. You can clean the mold yourself, but you need to educate yourself on proper clean-up methods, personal protection, and potential health hazards.
- Some people should NOT attempt to remove mold. If you suffer from immune disorders allergies or asthma you should avoid exposure to mold and mold spores.
- Take cautions not to expose individuals sensitive to mold. This includes infants under 12 months, people with a suppressed immune system, those with chronic lung problems (such as asthma, allergies and emphysema) and people recovering from surgery.
- Wear an N95 disposable respirator, eye protection and gloves
- Mold-contaminated materials should be sealed in plastic bags to prevent mold spores from contaminating another part of your house.
Level 2 (10 to 30 sq ft)
This clean-up would most likely involve an area the size of one complete wallboard panel. The recommendations for Level 1 also apply here, with the added precautio:ns
- Plastic sheets sealed with tape should cover moldy surfaces before mold remediation should be started in an effort to contain debris and limit dust. When a moldy piece of wallboard is to be cut out for example, a sheet of plastic should be taped into place to prevent mold spores from escaping. The cut section should then be contained within plastic and sealed with tape before it is disposed of
- Once mold remediation is complete, the area needs to be cleaned with a HEPA vacuum fitted with a high-efficiency particulate air filter then wiped down with a damp cloth.
Level 3 (30 to 100 sq ft)
This infestation would most likely involve patches of mold on several panels of wallboard. The recommendations are the same as for Level 1 and 2, with the following added precautions
- Ventilation ducts are to be sealed with plastic sheets and tape.
- The work area and adjacent areas need to be vacated until remediation is completed. It is further recommended that infants and individuals sensitive to mold find other accommodations away from the building until work is finished.
Level 4 (Greater than 100 sq ft)
This infestation would most likely involve entire walls and/or floors (carpeting) that may be thickly coated with black mold. The recommendations are the same as for Level 1–3, but with the following added precautions:
- All workers need to have completed training for safe handling hazardous materials,
- Workers need to wear full face respirators with HEPA cartridges. Disposable protective workwear is also required, including something to cover their heads. Disposable shoe covers are also needed to prevent the spread of spores.
- The work area must be completely isolated from the rest of the building using plastic sheets sealed with duct tapes.
- A “decontamination chamber” needs to be set up using a taped off area made from plastic sheets. Bags holding contaminated substances must be sealed and Hepa vacuumed or wiped down with a moist cloth in decontamination area before removing. Workers should also shed and discard exposed disposable clothing in the chamber.
- Before the building can be reoccupied Air monitoring should be completed to test to see if the building is adequately free of spores.
Level 5 (HVAC Systems and/or Air Conditioners)
The cooling coils and condensation pans in stand-alone air conditioners and HVAC systems are prime candidates for mold contamination. However, the clean-up of HVAC infestations are not for do-it-yourselfers.
The recommendations for a Level 5 remediation greater than 10 square feet are the same as for all the previous levels, with the following added precautions:
- Turn off the HVAC system
- Remove and seal into plastic bags any materials with the potential to support mold growth (ie: paper on the insulation of lined filters and ducts).
- HVAC manufacturers can recommend the best broad-spectrum antimicrobial biocides for use in their systems.