Indoor Air Quality

The average person spends 90% of their time indoors. Young children, older adults and those with chronic health conditions tend to spend even more time indoors and are more likely to be affected by indoor air quality problems.

Factors that affect indoor air quality include:

  • Indoor Air Pollutants, such as cigarette or cannabis smoke, cooking, household products (such as paints, cleaners and air fresheners), furniture, or building materials (such as pressed wood products and carpeting).
  • Outdoor Air Pollutants that can drift indoors, such as car and boiler exhaust, smoke or dust from a fire, or chemical releases. For information about what to do during a fire-related smoke event, see Air Quality: Fire and Smoke.
  • Temperature and humidity
  • Ventilation and air flow
  • Poor building maintenance can lead to cracks and leaks, which allow pest infestations, mold growth and building damage.

Improve Your Home’s Air Quality

To improve the air quality in your home, remove or reduce pollutant sources and regularly bring in fresh clean air from outside. Air filters and portable air cleaners can also help improve air quality together with air pollutant control and ventilation.

Follow these steps for better air quality:

Eliminate Secondhand Smoke

Cook and Heat Your Home Safely

  • Increase ventilation and air flow: If available, open a kitchen window or use your stove fan when you cook.
  • Never use a gas stove or oven to heat your home. It can create deadly gases and start a fire.
  • Never use a portable gas heater or charcoal grill in a closed space, including a garage.
  • Report problems with stoves or boilers to your landlord. If the problem isn't fixed in a timely way, call 311 or go to 311 online.
  • Test smoke and carbon monoxide detectors every month and replace removable batteries every six months. Replace detectors every five to 10 years, depending on the model. Building owners are responsible for installing approved detectors, and tenants are responsible for maintaining them.

Clean Your Home Safely

  • Open windows when using cleaning products.
  • Read and follow all warning labels and instructions.
  • Avoid using harsh cleaners. Use soap and water to clean surfaces, and baking soda to reduce odors.
  • Choose products that are fragrance-free. Avoid using fragrance plug-ins.
  • Never mix bleach with ammonia or with other cleaners. This can create dangerous gases.
  • Store cleaning produces safely away from children and pets.

Minimize Dust and Allergens

  • Use damp or microfiber cloths to dust.
  • Vacuum carpets and rugs, and wet-clean hard floors at least weekly.
  • Wash bedding weekly in hot water.
  • Place a floor mat at the front door to reduce outdoor dust.
  • Fix leaks to prevent mold. Safely clean mold if you find it in your home.
  • Use safe pest control methods to get rid of roaches and mice. Avoid foggers and sprays, as they are not effective and toxic chemicals can easily end up in places where people cook, eat and play.

Keep Temperature and Humidity Comfortable

  • On cool or dry days:
    • Open windows.
    • Make sure window guards are installed if a child younger than 11 lives or spends time in the home. Screens are not a substitute for window guards.
    • For homes near high-traffic areas, consider where windows are located before opening them. Only open windows at times when outdoor air pollution is low.
  • On hot or humid days:
    • Use an air conditioner or go to an air-conditioned place.
    • If possible, buy a portable or window air conditioner unit with a HEPA filter
    • If you have a central air system, buy an HVAC filter with a high MERV rating to capture more particles.
    • Run your AC in recirculation mode so it does not bring in air from outdoors. Keep windows and doors closed if the temperature indoors is comfortable. If the air conditioner provides a fresh air option, keep this closed.
  • High humidity can lead to mold growth. Humidity levels should be between 30% and 50%. You can measure this with an inexpensive humidity and temperature monitor from your local hardware store.
  • Building owners are required to provide tenants with heat between October 1 and May 31. Contact the owner if you do not have heat or hot water. Call 311 to file a complaint if the owner is unresponsive.

Renovate and Repair Safely

  • Use safe work practices and trained workers if any repair or renovation work disturbs lead paint or asbestos. If you’re a building professional, sign up for a lead safe work practice class.
  • Use wet cleaning methods and a HEPA vacuum to prevent the spread of dust and to clean work areas at the end of each day.
  • Never apply oil-based or moisture cure urethanes with high VOC levels on wood floors in an occupied building. Exposure to high chemical levels can cause health effects, including allergic reactions, organ damage and possibly cancer.

Choose the Right Air Filter and Portable Air Cleaner

Air filters and portable air cleaners (also known as air purifiers or air sanitizers) vary widely in their ability to remove air pollutants, but some can help improve indoor air quality. Air filters can clean the air throughout a home or building, while portable air cleaners clean air in a single room or area.

For guidance on how to choose the right air filter or cleaner for your space, see the U.S. EPA’s site on Air Cleaners and Air Filters in the Home.

  • No air cleaner can remove all pollutants from the air.
  • The most common air cleaners are designed to remove only particles and might not remove gases or odors.
  • The use of ultraviolet (UV) light in air cleaners does not effectively help to remove smoke from air.
  • Some air cleaners release ozone gas, a known lung irritant and asthma trigger. These should not be used under any conditions.
  • For more information on do-it-yourself (DIY) air cleaners, see EPA’s page on DIY air cleaners for wildfire smoke.

Health Effects and Getting Assistance

Health effects from indoor air quality problems can range from minor to serious, depending on the type of problem. Health effects can include headaches, tiredness, dizziness, nausea, itchy nose, irritated eyes and scratchy throat. The symptoms usually go away once a person leaves a room or building.

  • Talk to your doctor if you think you are having health effects from the air in your home.
  • Call 311 or go to 311 online to get more information about indoor air quality or to file an indoor air-related complaint

Additional Resources

More Information