@sueinmn Staying indoors on high ozone days, is better than going outside, and when you open a door, the ozone can come inside. Both N95 or KN95 respirator masks offer zero protection against ozone gas.

If one is concerned about ozone coming into the home, one can set up a clean room.

1. Choose the Right Room:
a. Pick a room large enough to hold everyone comfortably.
b. A bedroom with an attached bathroom is ideal.
c. Avoid rooms with fireplaces, large open spaces, or exterior doors.

2. Seal the Space:
a. Close all windows and doors tightly
b. Use tape or damp towels to seal gaps under doors.Keep windows locked to compress the seals.
c. Turn off kitchen and bathroom exhaust fans to avoid drawing in outdoor air.

3. Clean the Air:
a. Run a high-efficiency particulate air (HEPA) purifier continuously.
b. Ensure the purifier is sized correctly for that room's square footage.
c. Important for Ozone: To filter ozone gas, your purifier must include a heavy activated carbon filter. Standard HEPA filters only stop particles, not gases.

4. Adjust the Climate:
a. Use an air conditioner on "recirculate" mode if it is hot.
b. Ensure the AC fresh-air intake vent is closed.
c. Avoid using swamp coolers, which bring in outside air.

5. Keep the Room Clean:
a. Do not smoke, burn candles, or use gas stoves.
b. Avoid vacuuming, as it kicks up settled dust.
c. Wet-mop or wipe surfaces with a damp cloth if needed.