Indoor air quality in the United States is not overseen by a single agency. The Environmental Protection Agency (EPA) sets the national framework for indoor air quality in homes, schools, and other non-industrial buildings, while the Occupational Safety and Health Administration (OSHA) regulates workplace air for employees. State and local health departments, building codes, and housing authorities fill in many of the gaps. No federal law sets a single enforceable indoor air quality standard for the air inside an ordinary home.
That split surprises people. Most assume one agency monitors the air in every building. In reality, jurisdiction depends entirely on where you are standing — at home, at work, or in a public building — and which contaminants are involved.
Who Regulates Indoor Air Quality: EPA, OSHA, and the States?
The EPA is the primary federal authority for indoor air quality in non-workplace settings. It runs the Indoor Environments Division, publishes guidance on radon, mold, secondhand smoke, and volatile organic compounds, and manages programs like Indoor airPLUS for new home construction.
What the EPA mostly does not do is enforce indoor air standards in private homes. The agency has no legal authority to inspect your house or require you to fix a mold problem. Its role is research, guidance, and voluntary programs. Some of its rules do carry legal force — the radon and asbestos programs, for example, and pesticide registration under federal law.
OSHA regulates indoor air only in workplaces covered by the Occupational Safety and Health Act. It sets Permissible Exposure Limits for hundreds of airborne chemicals and enforces rules on ventilation, respiratory protection, and hazard communication. OSHA standards apply to employees, not to homeowners or tenants.
State and local governments hold much of the practical power. Building codes adopted at the state or local level govern ventilation and construction materials. State health departments handle radon programs, lead paint rules, and smoking restrictions. Local housing codes address mold, moisture, and habitability in rental properties.
What Does OSHA Actually Require for Workplace Air?
OSHA’s indoor air rules center on chemical exposure limits, ventilation, and protecting workers from known hazards. The agency enforces Permissible Exposure Limits for airborne contaminants and requires employers to keep exposures at or below those levels.
For most general office settings, OSHA has no specific indoor air quality standard. The agency does not regulate temperature, humidity, or carbon dioxide in offices as workplace hazards. It addresses indoor air complaints case by case, usually through its general duty clause, which requires employers to provide a workplace free of recognized serious hazards.
Where OSHA rules are specific and enforceable:
- Chemical exposure limits for solvents, dusts, and other airborne contaminants
- Respiratory protection programs when hazards cannot be controlled otherwise
- Hazard communication and training about airborne chemicals on site
- Ventilation requirements in certain industries, such as welding and painting
OSHA does not inspect homes or enforce air quality in residential buildings. If you rent an apartment and suspect a ventilation problem, OSHA is not the agency to call.
Why Is There No Single Indoor Air Quality Law?
The United States regulates outdoor air under the Clean Air Act, but no equivalent federal law covers indoor air. This is a deliberate gap, not an oversight.
Indoor air is treated largely as a property and personal responsibility matter. Congress has not passed a comprehensive indoor air law, and the EPA’s indoor air programs operate mostly through voluntary guidance and partnerships. The agency itself describes indoor air quality as a shared responsibility among federal, state, and local governments, building owners, and occupants.
The result is a patchwork. Radon is handled through state programs and EPA guidance. Lead paint has federal rules under the EPA and the Department of Housing and Urban Development. Tobacco smoke is regulated by state and local laws. Mold has no federal standard at all — the EPA publishes cleanup guidance but sets no exposure limit, and no federal agency enforces a mold threshold in homes.
This fragmentation matters when you have a problem. Knowing which agency to contact depends on the contaminant and the building type.
Which Agency Handles Which Indoor Air Problem?
Matching the problem to the right agency saves time and frustration. The table below reflects the general division of responsibility, though specific programs vary by state.
| Problem | Primary Authority |
|---|---|
| Radon in a home | EPA guidance; state radon programs |
| Lead paint in older housing | EPA and HUD rules; state health departments |
| Mold and moisture in rentals | Local housing codes; state health departments |
| Secondhand smoke in public spaces | State and local laws |
| Airborne chemicals at work | OSHA |
| Ventilation in new construction | State and local building codes |
| Asbestos in buildings | EPA rules; state programs |
| Carbon monoxide alarms | State and local building and safety codes |
For a home air quality concern, start with your state or local health department. For a workplace concern, OSHA is the correct agency, and workers can file a complaint without retaliation under the law.
Does the EPA Set Indoor Air Quality Standards for Homes?
The EPA does not set enforceable indoor air quality standards for private homes. It publishes health-based guidance and reference values, but these are not legal limits that a homeowner must meet.
One useful distinction: the EPA sets National Ambient Air Quality Standards for outdoor air under the Clean Air Act. Those are enforceable. There is no equivalent set of enforceable indoor standards for homes. People often confuse the two.
What the EPA does provide is practical guidance on radon testing and mitigation, mold cleanup, reducing volatile organic compounds, and improving ventilation. It also runs the Indoor airPLUS program, a voluntary certification for new homes that meet certain design and ventilation criteria.
For radon specifically, the EPA recommends fixing a home when the radon level is at or above 4 picocuries per liter (pCi/L). That figure is a widely used action level, not a legal requirement, and the EPA notes that no level of radon exposure is considered risk-free.
How Do State and Local Rules Change the Picture?
State and local governments carry much of the real regulatory weight for indoor air. Building codes adopted locally determine minimum ventilation, exhaust requirements for kitchens and bathrooms, and materials standards.
Some states go further than federal guidance. A number of states require carbon monoxide alarms in homes, and some require radon-resistant construction in certain areas. Smoking bans in workplaces and public buildings are almost entirely state and local matters.
Housing codes are where many renters find help. Local codes typically require landlords to maintain safe and habitable conditions, which can include addressing moisture and mold problems. Enforcement varies widely by city and county, and the practical outcome often depends on local inspection capacity.
One clarification worth knowing: the EPA and OSHA do not regulate the same buildings. OSHA covers workplaces. The EPA’s indoor air work focuses on homes, schools, and other non-industrial spaces. A school building, for example, falls largely under state and local authority with EPA guidance, not OSHA enforcement.
What Should You Do If You Have an Indoor Air Concern?
Start by identifying the likely contaminant and the type of building. That determines which agency can actually help.
- For radon, contact your state radon program or use an EPA-listed test kit; test before assuming your home is safe
- For mold in a rental, contact your local housing or code enforcement office
- For workplace air hazards, file a complaint with OSHA
- For lead paint, contact your state health department or the EPA’s lead program
- For general home air quality questions, your state or local health department is usually the best first call
No federal agency will inspect your home for free on request. Testing is generally the responsibility of the homeowner or tenant, which is why knowing the guidance matters more than knowing which agency to call.
Frequently Asked Questions
Does OSHA regulate indoor air quality in homes?
No. OSHA regulates workplace air for covered employees and has no authority over private homes or residential buildings.
Does the EPA enforce indoor air quality standards in homes?
No. The EPA publishes guidance and runs voluntary programs for homes but sets no enforceable indoor air quality standard for private residences.
Who do I contact about mold in my apartment?
Contact your local housing or code enforcement office, since mold and habitability in rentals fall under state and local law. The EPA provides cleanup guidance but does not enforce mold standards in homes.
What radon level does the EPA say should be fixed?
The EPA recommends fixing a home when radon reaches 4 picocuries per liter (pCi/L). That is an action level based on risk, not a legal limit.
