What is mold? A synonym for mold is mildew, both are commonly used terms to describe fungus or fungi. Fungi are a group of spore-bearing micro-organisms that grow where there is organic material (nutrient base,) moisture (or high humidity) and warm temperatures (between 40° and 100° Fahrenheit.) Fungi are ubiquitous in indoor and outdoor environments. Because of the recent scientific/medical association of mold with human illness, mold growth indoors has become a major public health issue.

Some problematic fungi, e.g. species of Aspergillus, Penicillium, Fusarium and Stachybotrys, have been associated with human illness and exacerbated symptoms of allergies and asthma. Note: Any fungi, not just the ones listed above, that has amplified in an indoor environment can be cause for concern.

What is remediation? According to the American Heritage Dictionary, remediation is defined as the act or process of correcting a fault or deficiency. Another definition is the act of remedying, defined as the means of curing, counteracting or repairing a loss, to restore or cure.

What is mold remediation? Mold remediation is a relatively new term that describes the synergistic efforts of industrial hygiene (IH) consultants and remediation contractors to effectively remove potentially harmful sources of indoor mold to a level that is reasonably achievable and is similar to background concentrations. The goal of the mold remediation project is to eliminate the source of mold and to provide a safe and healthful environment for the building occupants. The following is a consolidation of mold remediation guidelines to assist building owners, managers, IH consultants and remediation contractors.

Identifying Hazards

Prior to the initiation of a mold remediation project, someone has to first identify and define the scope of work. Generally, an IH who performs the initial indoor air quality (IAQ) study or hazard assessment, has performed testing that identified problematic fungi in a building. Subsequently, in a report with the analytical results, the IH will make recommendations for mold remediation. In some cases, the IH has identified problematic airborne fungi and has not clearly identified/quantified the source(s) At this time, someone has to perform a remedial investigation (RI) to identify, locate and delineate the source(s) the IH and/or the remediation contractor can perform this task. Ideally, both will participate, however, realistically, only one will generally perform the task. Some IH consultants will rely on the remediation contractor's expertise to quantify and delineate the contamination.

The RI may be an ideal opportunity for the remediation contractor to assess the details of the project. The RI should entail invasive and non-invasive methods. Invasive methods may include cutting large sections of walls or ceilings to visually observe mold contamination. Cutting small holes (1 inch to 2 inches) in the walls or ceiling can be useful when using a borescope or air-sampling device. Small pinholes (1/8 inch) can be advantageous when using moisture meters to detect moisture in building materials. Non-invasive methods include visual observations of mold growth, e.g. on stained drywall, roof rafters or basement walls. Non-invasive moisture meters can be used for detecting moisture in building materials but may be limited to depths beyond a few inches. Photographing the RI is recommended to document pre-abatement conditions and mold contaminated materials. In addition, measurements should be taken to qualify the extent of contamination (square feet or area per floor.)

The purpose of the RI is to quantify and delineate the mold contamination clearly define the scope of work. For the mold remediation contractor, this is very important. If there is a certain understanding of the scope of work, then the remediation project will proceed in a more orderly manner. Generally, when a remediation contractor performs the RI, he should prepare a brief summary of his findings, offer recommendations, a description of the methods for removal, a projected cost and a schedule to complete the scope of work. If the IH consultant performs the RI, then the results of the RI can be useful to obtain cost estimates from the remediation contractor.

Designing Mold Remediation Projects

Prior to commencement of remediation, a good design should include the results of the initial assessment, results of the RI and should address specific characteristics, safety issues, engineering controls and other methods of protecting building occupants.

The RI has defined the source(s) of mold-contaminated materials and the project design has addressed the methods of remediation. Did the design consider site characteristics, such as HVAC systems, air-conditioning units, interior furnishings, crawlspaces or repair and/or removal of the source of moisture? Do ventilation systems have to be shut down and protected during the remediation? Does the HVAC system need cleaning also? What about crawlspaces-do they need to be cleaned out, sanitized and/or sealed? Consider airflow-where is make-up air coming from? What air is entering the work area and is it contaminated with mold spores? Has the moisture source(s) been rectified? Is there a need for dehumidification? There are many questions that should be asked and answered in the design phase of the remediation project, and note that each project is different-there are no boiler plate specs to be used here.

Safety Issues

Safety issues must always be considered in remediation projects. Safety considerations include: use of personal protective equipment; awareness of electrical hazards (lockout tagout issues); slip, trip and fall hazards; use of scaffolds or lifts; entrances to confined spaces; chemical hazard communication; levels of respiratory protection and personal protective equipment; emergency and first aid procedures. Such safety issues can be summarized in a site-specific health and safety plan. Safety meetings should also be performed on site before commencement of and during the remediation project.

Remediation Methods

All mold remediation projects should be performed by qualified firms with trained workers (mold remediation technicians.) Technicians must be aware of the potential hazards associated with mold and understand the use of specific engineering and administrative controls to protect themselves and building occupants. The remediation methods should be consistent with currently available industry standards. Such standards include: The Institute of Inspection Cleaning and Restoration Certification (IICRC) 2500 Standard and Reference Guide for Professional Water Damage Restoration ; American Conference of Governmental Industrial Hygienists, Bioaerosols: Assessment and Control; The New York City Department of Health's Guidelines on Assessment and Remediation of Fungi in Indoor Environments. The following are recommendations and excerpts from current industry standards:

• The consensus is that building materials supporting fungal growth should be remediated as soon as possible in order to ensure a healthy indoor environment. Repair of the defects that led to water accumulation or elevated humidity should be conducted in conjunction with or prior to the mold remediation. The simplest and most expedient remediation that is reasonable and that properly and safely removes microbial contamination should be used. The goal of remediation is to remove and/or clean contaminated materials in a manner that prevents the emission of fungi and dust contaminated with fungi from leaving the work area and entering an occupied or clean area, while protecting the health of workers performing the remediation. Proper mold remediation methods should include the following:
• The work area designated for mold remediation and adjacent work areas should be unoccupied. Further, vacating people from spaces near the work area is recommended, more specifically, infants, persons having undergone recent surgery, immune suppressed people or people with chronic inflammatory lung disease, e.g. asthma or allergies.
• The work area should be demarcated, pre-cleaned with a HEPA vacuum and loose items removed. Loose items should be decontaminated and placed in plastic bags for safe storage or disposal. Material salvage ability will depend on the degree of contamination, material porosity and feasibility of cleaning. Fixed items that cannot be removed from the work area should be covered with polyethylene sheeting.
• Mold remediation technicians should perform all work while wearing the proper personal protective equipment, e.g. disposable Tyvek suits, respiratory protection, e.g. N95 filtering face piece or half-full face respirators with high efficiency particulate (HEPA) cartridges that comply with OSHA 29 CFR 1910.134, gloves, eye protection and foot protection.
• Small-scale source containment. Material removal with minimum dispersal of dust and spores, e.g. placing contaminated ceiling tiles in plastic bags prior to disposal.
• Local containment: A mini-containment or tent enclosure made of two (2) layers of polyethylene sheeting and duct tape with negative pressurization to prevent dispersal of dust and spores. Negative pressurization may be obtained by using a large HEPA vacuum or HEPA-air filtration device.
• Full-scale containment: A fully enclosed work area with critical barriers (2 layers of polyethylene sheeting, blocking all openings, fixtures and HVAC components to prevent the spread of dirt and spores beyond the contained work area and establishing negative pressure within the containment with HEPA-air filtration devices.) Enough air filtration devices should be installed to maintain a measurable amount of negative air pressure during the remediation process, generally a pressure differential of 0.02 inches w.g. (5 Pa) or more is recommended.
• Testing the negative air system should be performed by using manometers, smoke tubes to confirm air flow direction and/or other air flow monitoring equipment.
• Dust suppression methods, such as misting (not soaking) surfaces with a biocide, prior to remediation are recommended.
• Hygiene/decontamination facilities should be available on site. Workers leaving the remediation area (containment) should have access to soap and water to wash their hands and faces before leaving the site; ideally, showers and a portable decontamination unit should be available.
  o All waste materials should be double-bagged and wiped down before leaving the work area (containment.) Note: There are no specific requirements for the disposal of moldy materials.
• Final cleaning of the work area should consist of several alternating steps of HEPA vacuuming, wet wiping and misting with antimicrobial/biocide chemicals. This process should be performed at least twice within the work area and once outside the work area. Note: Antimicrobial chemicals or biocides should be EPA approved and their application or use must be consistent with manufacturer instructions. Material safety data sheets (MSDS) for such chemicals should be available on site.
• All areas should be left dry and visibly free of contamination and debris. Prior to reconstruction activities, building materials may require thorough drying using dehumidifiers and industrial desiccants.
• Quality control testing and post-remediation clearance testing. Documenting pre-remediation conditions can be performed by collecting air and wipe samples. Air samples may include spore counts and/or viable fungi with species identification.

During remediation air samples can also be collected to document and confirm that engineering controls are effectively working to control dust. Techniques for air monitoring include but are not limited to collecting spore/particle samples and the use of direct-reading aerosol monitors. The advantage of these two techniques is having quick results that will detect uncontrolled migration of contaminants. 

Note: The spore/particulate samples can be sent to a lab for 24 hour turnaround analysis and the aerosol monitors will show results immediately.

Post-remediation sampling may be performed by both the IH consultant (third party monitor) and the remediation contractor. Sampling may include a combination of the following: spore samples; viable bioaerosols; wipe samples for viable fungi.

Although, at this time, there are no specific regulations for mold remediation the guidelines set by state health departments and private organizations should be considered as defacto standards, meaning, these standards are publicly available and they should be followed by all remediation contractors or the remediation contractors are not demonstrating due care. Terms like "defacto standards" and "due care" are legal terms rightly mentioned in this article because of the potential liability associated with this industry. More and more legal cases are popping up with suits against contractors, building owners, developers and insurance companies. Obviously, the remediation contractors, IH consultants, and building owners must be mindful when they prepare for mold remediation.

The information mentioned in this article is only a summary of recommendations for mold remediation. Each remediation project is different and complex situations will arise. When preparing for a mold remediation project, consider the above information, seek out additional information, and stay informed of current issues. For more information, contact the (IICRC) Institute of Inspection Cleaning and Restoration Certification, American Conference of Governmental Industrial Hygienists (ACGIH), New York City Department Of Health (NYCDOH), Occupational Safety and Health Administration (OSHA), or the American Industrial Hygiene Association (AIHA).

Thomas Peter is an industrial hygienist and project manager of mold remediation for Insurance Restoration Specialist Inc. (IRS), an experienced, IICRC certified firm, performing mold remediation, water-damage restoration, and environmental services in the New York-New Jersey area. You can reach him by calling (732) 296-6666.