
Session #7
3:00-4:00 p.m., November 5, 2026
Augusta/Capitol/Pine Rooms Upstairs
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Mold Guidance Should Evolve: Rethinking Mold Conditions
Carl Grimes, HHS, CIEC
Hayward Healthy Home Institute - Monterey, CA
About this program:
The IICRC S520 Standard for Professional Mold Remediation introduced a spore-based framework of Condition 1, 2 and 3 - intended to distinguish between normal fungal ecology and active microbial growth. These categories became trusted foundational concepts within the remediation industry and continue to influence assessment, remediation, and post-remediation verification practices.
After 23 years of practical experience, however, it’s time to rethink the basis for the S520 Conditions. Additional factors have evolved technically and in the perception of both the industry and clients. Spore-counting is no longer the only factor for determining what constitutes actionable contamination, or how remediation decisions should be justified, or how to verify a successful remediation. In this presentation, participants will review the historical intent behind the IICRC condition classifications and explore how they are commonly applied in remediation and assessment projects today. I'll examine the distinction between the art of practical application and the myth of the scientifically proven, and introduce participants to additional characteristics in the application of S520 concepts that may better align remediation decision-making with building science, environmental data, and defensible professional judgment in service to their clients. Ultimately, the session encourages attendees to critically evaluate their own assumptions within the context of the powerful S520 framework.
What You'll Learn:
By attending this session, you will learn:
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The history and structure of the IICRC S520 Condition 1, 2, and 3 classifications
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How to differentiate between remediation-based condition ratings and laboratory analytical results
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Review the scientific and practical challenges associated with assigning structured conditions to the complexities of indoor environments
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Discuss evolving field experience while continuing to honor the intent of the S520 framework
About the Presenter:
Carl Grimes, HHS, CIEC, started as a victim of the indoor environment while enduring the ignorance of the 1980s. He published his book Starting Points for a Healthy Habitat in 1999 which caught the attention of the President of the Indoor Air Quality Association (IAQA). He presented at the first national conference and was then invited to participate in the development of the first mold remediation standard, IICRC S520. Carl has served as both a Board member and President of IAQA, served as a member of the Board of the International Society of Indoor Air Quality and Climate (ISIAQ). is a member of ASHRAE, currently serving as the chair of TC1.12 Moisture Management in Buildings, and the SGPC10 Interaction Affecting the Achievement of Acceptable Indoor Environments. All of which has led to conclude that what happened to him 40 years ago wasn't necessary, and still isn't necessary today.
Program Level:
Basic/Intermediate/Advanced
Content Area(s):
Mold Remediation and Verification, the Impact of Mold on Human Health, Mold Analysis Practices and Mold Testing Results, Investigating Mold and Chronic Dampness, Tools of the Trade, Case Studies, Mold Communications: Managing Occupant Concerns, Biocide use.