The Need for US Indoor Air Quality Guidelines

The report highlights a critical gap in US public health policy: the lack of comprehensive, science-based indoor air quality (IAQ) guidelines. While the US regulates outdoor air via the Clean Air Act, indoor environments—where people spend approximately 90% of their time—remain largely unregulated. The document details how pollutants like nitrogen dioxide from gas stoves and wildfire smoke exacerbate health risks, particularly for vulnerable populations. It reviews existing international models from the WHO and Health Canada, and limited US efforts in states like California and Texas. RMI recommends that the EPA use its authority under the Superfund Amendments and Reauthorization Act (SARA) to develop federal guidelines, which could then inform building codes, product safety standards, and electrification efforts to reduce combustion pollution.

• Indoor air quality is a major public health risk, yet it remains largely unregulated at the federal level and in most US states, despite people spending nearly 90% of their time indoors where pollutant concentrations can be two to five times higher than outdoors.
• Climate change is expected to worsen indoor air quality by increasing indoor heat stress, mold, ozone exposure, and exposure to wildfire smoke.
• Vulnerable populations, including children, the elderly, and low-socioeconomic households, face disproportionate risks from indoor pollutants; specifically, homes with gas stoves can have nitrogen dioxide (NO2) levels 50 to 400 times higher than those with electric stoves.
• The US Environmental Protection Agency (EPA) has the authority under Title IV, Section 403 of the Superfund Amendments and Reauthorization Act (SARA) to conduct research and disseminate information on indoor air, which could be used to publish IAQ guidelines.
• The EPA's existing indoor exposure limit for radon, established via the Indoor Radon Abatement Act of 1988, serves as a potential model for developing guidelines for other indoor pollutants.
• Various US states have implemented fragmented IAQ measures: California's CARB is updating NO2 guidelines, Illinois has voluntary guidelines under a 1994 Act, and Texas established voluntary guidelines for government buildings and public schools in 2002.
• IAQ guidelines can be applied across multiple sectors to improve health outcomes, including informing product safety benchmarks for the CPSC, updating building codes and energy standards, and enhancing voluntary certification programs like LEED and WELL.

APA

Prescott, N. (2023). The Need for US Indoor Air Quality Guidelines. RMI. https://rmi.org/resources/the-need-for-us-indoor-air-quality-guidelines/

Chicago

Prescott, Nina. The Need for US Indoor Air Quality Guidelines. RMI, 2023. https://rmi.org/resources/the-need-for-us-indoor-air-quality-guidelines/.

Wikipedia

{{cite report |last1=Prescott |first1=Nina |title=The Need for US Indoor Air Quality Guidelines |publisher=RMI |date=11 October 2023 |url=https://rmi.org/resources/the-need-for-us-indoor-air-quality-guidelines/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{prescott2023need, author = {Prescott, Nina}, title = {{The Need for US Indoor Air Quality Guidelines}}, institution = {RMI}, year = {2023}, month = oct, url = {https://rmi.org/resources/the-need-for-us-indoor-air-quality-guidelines/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }