Wildfires have grown exponentially in the Western United States and pose economic, ecological, and human health risks. As a result of arid climates, extreme temperatures, and neglected forest management, these events have destroyed millions of acres annually. During wildfires, smoke containing pollutants such as carbon monoxide, carbon dioxide, particulate matter (PM_2.5), and other organic compounds enter the atmosphere. One pollutant of concern, PM_2.5, can be inhaled into the human respiratory system and penetrate deep into the lungs.  

Many people are using do-it-yourself (DIY) air cleaners built using a standard box fan and a furnace air filter. These DIY air cleaners have been shown to filter out particles from wildfire smoke when used appropriately. However, there have been some concerns about DIY air cleaners and their safety since consumers are retrofitting box fans not intended or evaluated for this purpose by the manufacturer.

In 2021, Chemical Insights Research Institute of UL Research Institutes with support from UL Research Institute’s Fire Safety Research Institute partnered with the Environmental Protection Agency’s (EPA) Office of Research and Development to provide scientific information to help people stay safe during wildfire events. In July 2021, Chemical Insights Research Institute published a report that announced findings on the evaluation of potential safety risks while operating a DIY air cleaner and shared safety tips. Chemical Insights Research Institute and UL Standards & Engagement published UL 200A Guidance Document, “Use of Do-It-Yourself Filtration Devices During Wildfires.” This Guidance Document presents evidence-based, actionable procedures to help communities construct and safely use DIY air cleaners (furnace air filters attached to electric box fans) during wildfire smoke events. Further research will evaluate the chemical and particle contamination of homes during wildfire events and link the contamination to community health outcomes.