How to protect yourself from wildfire smoke

Smoke inhalation—not flame—is the primary cause of fatalities in wildfires, accounting for 50% to 80% of fire-related deaths according to the National Fire Protection Association. Wildfire smoke is far more than an unpleasant campfire smell; it is a complex, hazardous mixture of gases, volatile organic compounds, and microscopic particulate matter that can travel thousands of miles downwind.

Protecting yourself requires understanding what is in the air you breathe and taking systematic steps to keep indoor spaces safe.

What Makes Wildfire Smoke So Dangerous?

Wildfire smoke contains a blend of toxic gases—such as carbon monoxide, nitrogen oxides, formaldehyde, and acrolein—alongside millions of microscopic airborne particles. The greatest threat comes from particulate matter:

• PM2.5 (Fine Particles): Particles smaller than 2.5 microns penetrate deep into the lower respiratory tract, inflaming lung tissue and worsening chronic conditions.
• Ultrafine Particles: Representing roughly 90% of airborne smoke particles (smaller than 0.1 microns), these particles can pass directly through lung tissue and enter the bloodstream, potentially reaching vital organs.
• Biological Agents: Research shows that wildfire smoke can carry living microorganisms, such as bacteria and fungal spores, capable of causing secondary infections.

While smoke affects everyone, young children, older adults, pregnant individuals, and people with preexisting respiratory or cardiovascular diseases face significantly elevated risks.

Practical Steps to Protect Yourself

1. Create a Clean-Air Haven Indoors

• Seal your living space: Keep windows and doors shut tight. Close vents and fresh-air dampers that draw outdoor air directly inside.
• Adjust climate controls: Set your HVAC system or vehicle air conditioner to recirculate mode so outside smoke is not actively pulled into the cabin or home.
• Deploy true HEPA filtration: Run dedicated air purifiers equipped with high-efficiency particulate air (HEPA) filters and activated carbon to capture ultrafine particles and gaseous VOCs.

2. Stop Adding to Indoor Pollution

Indoor air can rapidly degrade during smoke events. While sheltering inside:

• Avoid burning candles, incense, or wood fires.
• Do not fry food or cook at high heat without adequate, filtered ventilation.
• Skip vacuuming unless your vacuum cleaner uses a certified HEPA filter, as standard vacuums exhaust fine settled dust back into the air.

3. Wear Proper Respiratory Protection Outdoors

Standard cloth face coverings and loose surgical masks do not create a tight seal or filter fine particulates. If you must go outside:

• Use a fitted respirator rated N95, KN95, N100, or FFP2.
• Ensure the mask fits snugly against the bridge of the nose and cheeks without gaps.

4. Track Real-Time Air Quality

Wildfire plumes shift quickly based on shifting winds and regional weather patterns.

• Monitor local indices using tools like the AirVisual air quality monitoring app or dedicated air quality monitors.
• Check PM2.5 levels before planning any essential outdoor movement or travel.

Taking these precautions before smoke settles into your neighborhood ensures that even when outdoor air quality reaches hazardous levels, your indoor environment remains a safe sanctuary.