Home > Protecting yourself from wildfire smoke

Heartfelt thanks to the more the tens of thousands of firefighters in California who risk their own lives every year to protect us. Imagine how much worse it would have been without firefighters on the frontline every day putting their lives at risk to save our lives and our homes! We would like to express our deepest gratitude and respect for all the firefighters and first responders for their selfless sacrifice.

California continues to experience longer wildfire seasons as a direct result of Climate Change. As of August 15, 2024, a total of 5,195 wildfires have burned a cumulative 820,160 acres. The number of wildfires and the number of acres burned are higher than the five-year average. Wildfires have destroyed 1,030 structures and killed one person in the state in 2024.

Californians face danger from wildfires and wildfire smoke every year. Fires and smoke are dangerous for everyone, but especially for children and older adults and those with lung disease. There are steps you can take to understand and avoid exposure to wildfire smoke and choose the right respiratory protection.
Be sure to prepare for power outages during wildfire season as well, especially if you use a medical device reliant on electricity, such as a CPAP machine.

Wildfire Information from the Centers for Disease Control

Tips to reduce smoke exposure

  1. STAY INDOORS: Staying inside with the doors and windows closed can usually reduce exposure to ambient air pollution by at least a third or more.In any home, if doors and windows are left open, particle levels indoors and outdoors will be about the same.If outdoor temperatures are very high, and you have noair conditioning ,stay with friends or with family members who do have it, go to a cleaner air shelter in the community, or leave the area.
  2. REDUCE ACTIVITY: Reducing physical activity is an effective strategy to lower the dose of inhaled air pollutants and reduce health risks during a smoke event. During exercise, people can increase their air intake as much as 10 to 20 times over their resting level. Increased breathing rates bring more pollution deep into the lungs, and people tend to breathe through their mouths during exercise, bypassing the nose’s natural filtering.
  3. REDUCE OTHER SOURCES OF INDOOR POLLUTION: Smoking cigarettes, using gas, propane and wood-burning stoves and furnaces, spraying aerosol products, frying or broiling meat, and burning candles and incense can all increase particle levels in a home and should be avoided during wildfires. To avoid re-suspending particles, do not vacuum during a fire event, unless using a HEPA-filter equipped vacuum.
  4. USE AIR CONDITIONERS AND FILTERS: Homes with central air conditioners generally have lower amounts of outdoor particles indoors compared to homes that use open windows for ventilation. Most air conditioners are designed by default to re-circulate indoor air. Those systems that have both “outdoor air” and “re-circulate” settings need to be set on “re-circulate”during fire/smoke events. Also, central heating and/or air conditioning systems (and some room air conditioners) contain filters that can remove some airborne particles. Filters need to be replaced regularly, and should fit the filter slot snugly. If a filter upgrade has been performed (e.g., a filter rated at MERV 8 or higher has been installed), during a wildfire smoke event, the central system’s circulating fan can be set to operate continuously.
  5. USE ROOM AIR CLEANERS: High-efficiency particulate air (HEPA) filter air cleaners and ESPs documented not to produce excess ozone can help reduce indoor particle levels, provided the specific air cleaner is properly matched to the size of the indoor environment in which it is placed. There are wide ranges of air cleaners and prices to choose from, from less expensive portable units designed to clean the air in a single room ($90 -$900) to central air cleaners intended to clean the whole house ($450 -$1500). Central air cleaners can be more effective than room air cleaners because they filter a larger amount of air, but two or more well-placed portable air cleaners can be equally effective and their cost may be less than the a central air cleaner. Only portable (room) air cleaners that do not produce excess ozone should be used. California Air Resources Board (CARB) certifies air cleaners that produce little or no ozone; see their list of certified air cleaners at: http://www.arb.ca.gov/research/indoor/aircleaners/certified.htm.
  6. AVOID OZONE GENERATORS: Some devices, known as ozone generators, personal air purifiers, “super-oxygen” air purifiers, and “pure air” generators, are sold as air cleaners, but the position of public health agencies, including the California Air Resources Board and U.S. Environmental Protection Agency, is that they do more harm than good. Relatively low levels of ozone can irritate the airways, causing coughing, chest pain and tightness, and shortness of breath. It can also worsen chronic respiratory diseases such as asthma, as well as compromise the body’s ability to fight respiratory infections.
  7. CREATE A CLEAN ROOM IN YOUR HOME: If you cannot follow all the recommendations above in your entire home, create a “clean room” and stay there during wildfires. A good choice is an interior room, with as few windows and doors as possible, such as a bedroom. This is especially important for vulnerable populations such as those with lung disease.
  8. HUMIDIFIERS: Humidifiers are not air cleaners, and will not significantly reduce the amount of particles in the air during a smoke event. Nor will they remove gases like carbon monoxide. However, humidifiers and dehumidifiers (depending on the environment) may slightly reduce pollutants through condensation, absorption and other mechanisms. In an arid environment, one possible benefit of running a humidifier during a smoke event might be to help the mucous membranes remain comfortably moist, which may reduce eye and airway irritation.
  9. INSIDE VEHICLES: Individuals can reduce the amount of smoke in their vehicles by keeping the windows and vents closed, and, if available, operating the air conditioning in “re-circulate” mode. However, in hot weather a car’s interior can heat up very quickly to temperatures that far exceed those outdoors, and heat stress or heat exhaustion can result. Children and pets should never be left unattended in a vehicle with the windows closed. Also, carbon dioxide levels can quickly rise to very high levels due to occupants’ exhaled breath, so drivers should pull over and open windows when it is safe to avoid becoming groggy. Vehicles should not be used as a shelter, but as means to get to one or leave the area.
  10. RESPIRATORY PROTECTION: Covering the mouth with a (damp or dry) bandana, handkerchief, or tissue, or using a loose surgical mask or painting mask will not prevent the wearer from breathing in airborne particles. N95 particulate filtering facepiece respirators or respiratory protection devices with a higher level of protection are more appropriate for the public for wildfire hazards. Purchase such respiratory masks to have on hand for such emergencies if you live in fire-prone areas.

(Condensed from: Wildfire Smoke:A Guide for Public Health Officials, Revised May 2016; U.S. Environmental Protection Agency, U.S. Forest Service, U.S. Centers for Disease Control & Prevention, and California Air Resources Board)