By Bob Baker

A topic that has received considerable discussion recently is what, if any, respiratory protection technicians working on or in HVAC air handlers, cooling towers and other components potentially contaminated with microbial growth should utilize. The discussion accelerated when the IICRC S-520 Standard (Standard and Reference Guide for Professional Mold Remediation) was published in December of 2003.

That document contained an appendix (B - "Suggested Guidance for the Selection and Use of Respiratory Protection") that took what many in the industry consider an overly cautious approach to respiratory protection for workers engaged in mold remediation. Some have argued that a person out walking in the woods can be exposed to greater concentrations of fungal (mold) spores than the average worker on a mold restoration project.

Facts are not clear

The committee of experts that wrote the S-520 Standard was far from comfortable mandating a high level of respiratory protection. The evidence for that is that the Respiratory Guidance is offered as an Appendix rather than being part of either the Standard or Reference Guide. There were some who argued passionately that it should not have been included at all. This is because there is not really good data about how much risk a mold remediation worker (or an HVAC technician) faces from exposure to spores and viable organisms during their work activities.

The entire subject of whether mold exposure constitutes a health risk or not remains unresolved within the medical community. Most health researchers agree that there is some relationship between damp (and moldy) buildings and certain respiratory symptoms. It is also commonly accepted that many individuals are sensitive to fungal spores and experience an allergic (sometimes severe) reaction to mold. What remains unproven is what impact, if any, mold has on overall health of otherwise healthy individuals.

Arguments for a high level of protection Although well controlled studies do not exist, many in our industry insist that workers who are exposed to the interior of HVAC system components day after day eventually develop a reaction to such exposures. Reportedly, these individuals become unable to continue their work activities unless they use respiratory protection. There are some reports that some workers have been forced to change to another career their reactions to even brief exposure become so severe.

Like all "stories" these are difficult to quantify or validate. It is possible that what these individuals experience are common changes to immune system response connected with the aging process. It is well established that immune or allergic response can change over a person's life. Many children "outgrow" allergies as they mature. Other individuals become allergic to substances that never seemed to trouble them in the past. The human immune system is highly complex and imperfectly understood by medical science.

Since there is some evidence for risk many argue for the highest possible level of protection. This is often called the "Precautionary Principle". It is a controversial theory that suggests that if you are unable to prove that a substance or practice is safe, you should assume that it is not and adopt the highest level of protection or avoidance until such time as safety can be proven.

For those who accept the Precautionary Principle, a high level of protection is reasonable because if the risk is proven at some time in the future, those who did not mandate respiratory protection for their employees may be liable for any health consequences.

Arguments against protection

There are several arguments that are advanced against the Precautionary Principle. It is well accepted that life incorporates many risks and it is not possible or practical to protect against each and every risk that we may encounter. Respiratory protection represents a cost of doing business that many argue is unreasonable given the lack of evidence of health effects from exposure to mold and other organisms that may be present in HVAC systems. In addition, the sight of workers wearing such protective devices may needlessly frighten occupants of spaces served by HVAC systems they are servicing or inspecting.

Many argue that those who advocate requiring respiratory protection are doing so only to make their work seem more dangerous or complex than it really is so they can justify higher labor rates. The "over-dramatization of the risk posed by mold certainly is a valid concern as "mold hype" has caused significant confusion on the part of industry professionals and the general public alike. It would be disappointing if some professionals advocated excessive personal protection for self-serving reasons.

Sorting it all out

A new debate on proper respiratory protection will soon start. The IICRC decided at the time that the S-520 Standard was published that they would actively seek comments on the document and quickly form a new committee to review those comments and consider the need to revise portions or all of the Standard.

During the first half of 2004, a number of meetings were held around the US to introduce the new Standard and discuss its contents. Included in the comments received, were a number relating to the Respiratory protection guidance in Appendix B. Several either felt the guidance was overly strong or should be removed entirely. The new committee has been formed and will soon start discussing what changes need to be made in response to the comments received and new research and findings about mold remediation.

Fortunately or unfortunately (depending on your view) I will be able to keep you informed on the progress of these deliberations. I accepted an invitation to chair the new committee.

Bob Baker is a member of IAQA, ASHRAE, CSPA and Chairman and CEO of BBJ Environmental Solutions, Inc., "The Standard of Care for Indoor Air". BBJ has offices in Tampa and Hong Kong and Mr. Baker follows indoor air quality developments throughout the world. For additional information, Mr. Baker can be reached at (800) 889-2251 or through the company web site at www.bbjenviro.com.