Overview of Major Mold Guidelines

Written by Ralls Melotte

Although some states have regulations regarding the management and remediation of mold, Illinois does not, nor are there federal regulations.  Consequently, several organizations have developed Guidelines for mold.  The ones most recognized include the following:

New York’s Guidelines were initiated in 1993 and were probably the result of the concern over the relationship between Stachybotrys and Legionnaire’s disease.  As such, it has a stronger emphasis on the toxic characteristics of fungi in buildings even though since then, it has been established that there is no relationship.

In the early 2000’s, OSHA prepared its guidelines with an emphasis on exposure issues for workers working in mold contaminated spaces.

EPA produced their guidelines approximately the same time with an emphasis on schools and commercial building exposure to occupants.  Consequently, these three guidelines are fairly similar in their recommendations.


In summary:

  1. Mold is a naturally occurring, living organism found throughout the world. It grows on organic material, has heat tolerances similar to humans and needs moisture to start its growth.   There are thousands of types of mold (species), divided into hundreds of families (genera).  Each species has preferences on the amount of moisture needed to thrive as well as the organic material it can grow most successfully on.


  1. There are many varieties of mold that prefer cellulose for growth and can survive on humidity from the air once the growth has been established. These molds are far more prevalent in buildings and cause damage to the building as well as poor health conditions for the occupants and are the primary focus of all three publications.


  1. Due to the operation of exhaust fans, HVAC systems, doors and windows and the natural changes in barometric pressure, there will always be some level of airborne mold in buildings. In mold management, the goal is not to be mold-free, but to avoid elevated levels of airborne mold to accumulate within the buildings, nor to allow mold growth on the building materials in buildings.


  1. Although North America has few toxic molds, all molds can cause allergic reactions in certain individuals. As a rule of thumb, infants up to 2 years and senior citizens are more susceptible to dramatic mold induced allergic reactions.  In addition, individuals with asthma or other respiratory issues, compromised immune systems, etc. are more susceptible to allergic reactions to mold.  For this reason, just because the majority of individuals are not affected by the presence of mold doesn’t mean that someone couldn’t have an extreme reaction.  All complaints should be taken seriously.


  1. Although mold on visible surfaces is normally easily identifiable as mold, many times mold growth on building materials is located in hidden locations, i.e., inside walls and ceilings, inside HVAC equipment, behind cabinets, etc. Air sampling is reasonably inexpensive and can verify if there are elevated levels of mold in a location where there have been complaints, but no obvious growth.


  1. Sampling can be “viable’ or “non-viable,” which refers to whether the mold is being identified by its general family (genus) or by its particular species. Viable sampling is more expensive and takes longer to analyze and limits its analysis to mold spores that can cause further growth.  Since the most commons concerns about exposure are from the allergic reaction, some individuals have reactions to mold exposure and it doesn’t matter if that exposure is to spores or hyphal fragments (mold debris incapable of producing new mold).  Consequently, non-viable sampling is conducted because it can any presence of mold, not just spores.


  1. Lift samples can also be collected, but it is difficult to quantify the results other than to say mold is present.


  1. Air sample results from different locations in a building are compared to each other, the levels outside and sometimes to other buildings. Unlike most other contaminants, there is no established Permissible Exposure Limit (PEL) to mold since, among other reasons, prevailing mold levels vary from location to location.  Texas will have a different concentration of mold and different molds from Oregon, Maine will have different levels from Los Angeles and living near a lake or marsh will have different levels than a location 5 miles away.


  1. The guidelines agree that the recommendations for personal protection, need for containment, level of skill and training of the workers and need for post remediation sampling vary depending on the parties potentially exposed, the amount of fresh air that can be brought into the work area and the extent of mold present.


  1. All three guidelines agree that Small Isolated Areas of mold 10 square feet or less can be cleaned by individuals with proper knowledge of the materials they are using, adequate fresh air and minimal personal protection.


  1. Mid-Sized Isolated Areas of 10-30 square feet can be conducted by maintenance staff with training and personal protection.


  1. Large Isolated Areas of 30 – 100 square feet need guidance from safety professionals with experience in microbial investigations with the work conducted in containments by trained personnel and proper personal protection.


  1. Depending on the specific conditions of the potential for mold exposure, further procedures and protection may be needed for any size mold contaminated area.


  1. It is generally recognized that taking airborne levels prior to remediation and after the work is complete provides the best indication if the work has been performed satisfactorily. In addition, since there will never be a mold free space, the fact that there is mold still present after remediation, but at acceptable levels, helps protect the building Owner from liability.


  1. Real estate transactions are routinely asking questions about any mold history for a building. A written report of the activities, sample results prepared by a professional with appropriate training helps answer questions that might come up as well as questions that could be raised by concerned individuals in the building.

Mold, Asbestos, & Lead Paint Consultant