Derrick Denis

Clark Seif Clark, Inc. (CSC)

Vice President of Indoor Environmental Quality

Derrick A. Denis, has spent his working lifetime anticipating, recognizing, evaluating, controlling, and confirming common and emerging environmental hazards from the stinky to the deadly and all points in between. As a practitioner, inventor, educator and volunteer Mr. Denis has provided professional environmental health and safety (EH&S), industrial hygiene (IH) and indoor environmental quality (IEQ) services for over 28 years and over 20,000 projects domestically and abroad.  He has served over 22 years as V.P. of IEQ with the environmental consulting firm Clark Seif Clark, Inc. (  Mr. Denis is an inventor of Sewer Gas Solutions, a product preventing sewer gas infiltration by inhibiting the evaporation of water from plumbing traps (  His history of volunteerism has included positions on numerous Boards of Directors for IEQ Industry Organizations (e.g. IAQA, EIA-AZ, ACAC, etc.).  For over 17 years Mr. Denis has filled the role of Director for the Phoenix Chapter of the Indoor Air Quality Association. He holds a B.S. degree in Environmental Science and numerous relevant certifications/accreditations (e.g. CIEC, CEOP, CIAQP, CAC, etc.).  Mr. Denis has instructed hundreds of IEQ-related educational sessions around the world.  He has provided expertise on numerous legal cases for both Plaintiffs and Defendants.  He has appeared on television, been quoted in major & local newspapers, authored many industry articles, and published in peer-reviewed scientific literature. Mr. Denis is the industrial hygienist for the Disaster Ready Emergency Preparedness and Infection Control Program (DR EPIC) in Arizona.  He has contributed educational content (lectures, courses, video tutorials, articles, etc.) to many healthcare associations including California Association of Healthcare Facilities (CAHF), Arizona Healthcare Association (AHCA), Utah Healthcare Association (UHCA) and Georgia Healthcare Association (GHCA).