The Top Ten Mold Myths
Replacing Hysteria With Science

Douglas A. Rice, PhD
Laboratory Director
Environmental Microbiology & Industrial Hygiene
Colorado State University

  1. Mold is the next asbestos

    While mold may be considered the next asbestos for financial reasons, it cannot be considered the same environmental hazard. There are many factors involved in the differentiation of mold and asbestos. Mold is a natural part of our environment. Chunky Blue Cheese Dressing contains 230,000 spores per gram. If this bottle of dressing spilled onto a wall, most of the "mold experts" would suit up in full-face respirators and full Tyvek suits to remove the entire wall under containment.

  2. Industrial Hygienists are the best mold experts

    There are currently more mold experts than species of indoor mold. Mold will return after every water loss. True mold experts are somewhat rare. Look for an expert that understands the organism and the building systems taht allowed the growth while maintaining the practical sense that the mold is a common part of our environment.

  3. Clearance sampling is always necessary

    The value of clearance sampling is relatively obvious. A document is issued at the end of the remediation that states, On this day, at this time, the airborne mold populations inside of the building are lower than the control populations outside of the building. It is important to note that no state, local, or governmental standards exist for mold spore populations. Comparing indoor air with outside air is the best situation. One difficulty of this method is the presence of settled spores inside of a house. Over the year, spores are deposited on carpets, couches, windowsills, etc. During sampling, the spores may be disturbed and become re-entrained in the air. This may give an unusual high population or demonstrate mold genera that were not sampled outside. The outdoor sample, being from a single season, will not represent all of the potential genera for that location.

  4. All of your belongings must be disposed of in a moldy environment

    Mold contamination of contents is currently the hottest debate in the industry. As with ductwork, there is always a potential for furniture and personal possessions to become contaminated during a mold loss. It is difficult to determine how much "more" contaminated teh contents have become over background levels. Even if the mold loss contributed a few spores per inch of surface, there are no standards for surface populations. All content items are cleanable if mold was not actually growing in the material due to saturated conditions. Hard surfaces can be wiped off, porous surfaces can be HEPA vacuumed and clothes can be laundered. There is no way for the spore to burrow into furniture or wood surfaces.

  5. Ductwork must be cleaned or demolished during a remediation

    Duct systems can be contaminated by mold proliferation in a building. It is nearly impossible to determine how much this contamination contributes to the resident mold population in the duct. Since duct systems recirculate indoor air and transmit outdoor air, spore levels can become quite high. A common "trick" used by some Industrial Hygienists is to collect a sample inside of the duct by the mold loss. Demolition of ductwork is not necessary unless: 1) the duct has been saturated and 2) the duct contains interior lining. Sheet metal does not support growth if the system is not lined. Mold has no mechanism for motility. The spores rely on air currents for transport. If an air return vent is not in the same room as the mold growth, there is little chance for contamination of the duct.

  6. All mold spores must be removed during the remediation

    Mold spores are found everywhere in our environment, so complete remediation of all mold spores is never possible. Mold remediation is designed to return a building to a pre-loss condition. Prior to a water loss, a vast diversity of mold spores will populate the biding, but none of them will be actively growing. In reality, there is never a zero liability situation. The mold spores are built into the structure with lumber, drywall, insulation, carpet, etc.

  7. Dead mold is just as hazardous as living mold

    Spores will not live forever and the allergens and toxins present on the spore coat will slowly oxidize over time losing potency and effectiveness. Ironically, oxygen is the critical component of life for most organisms and yet it eventually destroys all organic material through oxidation.

  8. Containment is always necessary in mold remediation

    The ultimate purpose of containment is to keep clean areas clean. If an entire building is contaminated, containment is not necessary. If the mold is exposed to the outdoor environment, containment should not be used to prevent outdoor release. Containment must be designed for the specific project.

  9. You must identify the mold prior to remediation

    Most sampling is not necessary. Air, swab, bulk and dust samples are not necessary to confirm the presence of visible mold growth. Air sampling may become necessary if some source of hidden mold may be making the family sick.

  10. The EPA and NYC Guidelines were written as standards for the remediation industry

    In 1993 the New York City Department of Health published the first set of guidelines for the assessment and remediation of mold. This original document discussed the hazards and remediation strategies for Stachybotrysatra. In January 2000, the guidelines were revised to include all types of indoor mold because inhalation of fungal spores, part or mycotoxins from a wide variety of fungi may lead to or exacerbate allergic reactions, cause toxic effects or cause infections. In March 2001, the Environmental Protection Agency published their set of guidelines. Both of these documents were written for building engineers, custodians and managers who may be presented with a mold problem. They were NOT created as law or standards for the remediation industry. In fact, both documents are filled with flexibility that allow you to consult your "remediation expert" for unique situations. All of the remediation techniques, personal protection and containment strategies are based on the amount of contiguous growth, and not the species of mold.