ICS Magazine

Ionizing Air Cleaners in Mold-Contaminated Sites

July 12, 2005


Q: Is it acceptable to temporarily install ionizing air cleaners on a mold-contaminated work site until we can get the remediation work started?

A: First of all, we need to define "ionizing air cleaners." We are not talking about a HEPA air filtration device (AFDs) or negative air machine (NAM), such as those that are used on a mold remediation or asbestos abatement jobsite. Unlike the AFDs, or HEPA air cleaners that are designed for use in a residential environment, ionizing air cleaners create an electrical charge in the surrounding air space, that can result in charged molecules known as ions, which are suppose to cling to oppositely charged airborne particles and surfaces. Ionizing air cleaners, also known as electrostatic precipitators, add an oppositely charged collection plate designed to attract the particles.

The problem with some units is that they can produce ozone. In a May 2005 article titled, "New concerns about ionizing air cleaners," Consumer Reports reported that, with respect to the issue of ozone and ionizing air cleaners:

"Unlike ozone in the upper atmosphere, which helps shield us from harmful ultraviolet rays, ozone near ground level is an irritant that can aggravate asthma and decrease lung function. Air cleaners need not meet ozone limits - not for the federal Environmental Protection Agency, which regulates only outdoor air, nor for the Food and Drug Administration, since it doesn't consider them medical devices, despite the health benefits that some ads imply...Manufacturers often submit air cleaners to a voluntary standard that includes a test to see whether they produce more than 50 parts per billion (ppb) of ozone, the same limit the FDA uses for medical devices."

In addition to the potential for creating ozone, these units do not move a lot of air. Therefore, their use is questionable as a solution for a mold-contaminated area of a home. Even if the units were to move a greater volume of air, they still would not solve the contamination problem. If there is a mold problem, then there is a source. That source disperses spores into the air space due to airflow or a negative pressure. When you install an air cleaner or purifier, or for that matter a HEPA-filtered negative air machine in the vicinity of the source of contamination, the airflow and negative pressure required to move the air through the system will also help draw mold spores from the source through the air space and hopefully into the unit. The result is that more spores are being moved from the source to the area of negative pressure.

If the area is contaminated, it would seem to me to be prudent to contain the area, isolating it from the uncontaminated area. That way there is not going to be a continual dispersal of spores from a contaminated area to a clean area. Once contained, it really doesn't matter if there is a continuation of the dispersal inside containment. The reality is that once remediation starts, the levels inside containment are going to increase anyway. Since there is going to be an increase in the spores levels, the use of an air purifying device whether ionizing or not, does not improve anything. It will only add cost or worse, leave you and the occupants with a false sense of security.

The other possibility is that you only suspect that the area is contaminated. In either case, my concerns are still the same. At this time the evidence seems to indicate that most household ionizing air cleaners would not help your situation. It is my advice to stick with the IICRC S520 Standard and Reference Guide for Professional Mold Remediation that has been adopted for the industry and use containment with HEPA-filtered air filtration devices.