The ANSI/IICRC S500 2015 Standard and Reference Guide for Professional Water Damage Restoration (S500-2015) contains changes on many important topics, not the least of which is the use of air filtration devices (AFDs).

This article explores the new language, and provides practical guidance on how to apply these changes in your restoration company.


Air filtration devices, or AFDs, are often used in the restoration industry to help control aerosolized soils at different stages of structural restoration. Their importance and benefit vary depending on several factors, including the cleanliness of the space, the sensitivity of occupants to airborne irritants and other contaminants and the methods used during the restoration process itself.

In this article, we will discuss how the ANSI/IICRC S500 2015 Standard and Reference Guide for Professional Water Damage Restoration (S500-2015) addresses the use of AFDs and how it differs from similar language in the previous 2006 edition of the document.

We will further explore how these changes may impact your restoration processes.

What changed?

There are 27 references to AFDs in the new S500-2015. Of those, only three exist within the standard section of the document. The rest are contained within the reference guide. Although the number of times the term appears in the standard section is quite small, it’s important to note that in the previous edition (S500-2006) the term appeared six times within the standard.

This decrease is due to one specific section of the standard: Section in the S500-2015, Controlling Airflow (formerly 12.1.20 in the S500-2006). Here, a paragraph referring to aerosolized soils and contaminants in the presence of airflow has been omitted from the standard section in the 2015 document.

Similar language still exists in the S500-2015; however, it is only contained within the reference guide. The word “should” (a trigger word indicating standard of care language) does appear in the paragraph. The paragraph opens with an important health and safety concern:

“Airmoving devices inherently tend to aerosolize soils and particulates present in the environment. As water evaporates from surfaces and materials such as carpet, more particles often become aerosolized, creating possible health, safety, comfort and cleanliness issues.”

The concern is straightforward: blowing air around a space can make particles airborne. But instead of leaving it at that, the S500-2015 incorporates a clear call to action:

“Restorers should perform a preliminary cleaning of materials and surfaces (e.g., carpet, hard surface floors, exposed subfloors) to reduce the amount of soil or particulates that can become aerosolized, before activating airmoving devices. Where preliminary cleaning cannot sufficiently remove soil or particulates, or there are high-risk occupants, restorers can install one or more air filtration devices (AFDs).…”

The key word here is, of course, “should,” a word defined by the S500-2015 as “… a component of the accepted ‘standard of care’ to be followed…” In short, restorers should clean surfaces before using airmovers, and when that doesn’t alleviate concern, you can use air filtration devices.

How the change impacts the process

It is important to identify potential health and safety concerns, including those associated with indoor air quality, during and after the restoration process. Where concerns are present, it is equally important to (a) document the concern and (b) implement controls to address the concern.

The language states plainly that surfaces should be cleaned prior to airmover use, regardless of the category of loss. Initial cleaning has been a common step in restoration for some time, but not necessarily as a standard of care for all projects.

Another purpose of this change was to place a stronger emphasis on the need to document conditions that lead to the use of the device.

Other references to air filtration

In addition to the term AFD, the S500-2015 discusses filtration of air using the terms “Air Scrubber” (four instances) and “HEPA” filters (over 40 instances). These terms, however, are used primarily in reference to contents cleaning, HVAC system cleaning and processing or in the context of remediation.

As an example, in section 12.3.2 of the standard, the document states that “an in-line HEPA filter should be used” when drawing moist air out of potentially contaminated cavities in a Category 2 or 3 water loss. This language requires the use of either an inline filter or a sufficient capacity air scrubber, and that the wall drying system be installed to place the cavity under negative pressure.


Despite the fewer references to air scrubbing devices in the S500-2015, AFDs are still a significant part of the cleaning and restoration process. As with many of the practices used in the field today, understanding and documenting the purpose and benefit of their use is becoming increasingly important. Where contaminants or irritants are at risk of becoming airborne, start with a thorough cleaning. Where cleaning either isn’t practical or sufficient, an air scrubber will improve the restorer’s likelihood of providing a clean environment both during restoration and after the project is complete.

We’ll continue to explore changes in the S500-2015 in this series of articles. If you haven’t already, it’s probably time to pick up your copy of the S500-2015!

Brandon Burton is the technical director for Legend Brands and an instructor with the Restoration Sciences Academy (RSA). He teaches IICRC-approved classes in the categories of Applied Structural Drying (ASD) and Water Damage Restoration (WRT). Burton has served the restoration community for more than 20 years, including 15 as an IICRC-approved instructor, ANSI/IICRC S500 chapter chair, RIA restoration council member and in many other industry roles. You can contact him at [email protected]