Minnesota Wildfire Smoke, Indoor Air Quality (IAQ), and Practical Steps to Protect Building Occupants
With ongoing drought conditions and widespread wildfire smoke affecting Minnesota and much of the Upper Midwest, facility managers are facing a growing indoor air quality (IAQ) challenge. Smoke from Canadian wildfires has repeatedly reduced air quality across the region, creating health concerns for employees, students, patients, and building occupants—even hundreds of miles from the nearest fire.
Wildfire smoke doesn’t stay outdoors. Fine particulate matter can enter commercial buildings through ventilation systems, open doors, loading docks, and small gaps in the building envelope. Without a proactive response plan, occupants may be exposed to unhealthy indoor air, even when they are inside what appears to be a well-maintained building.
This article explains what wildfire smoke means for your facility, how it impacts indoor air quality, and practical steps organizations can take to reduce exposure and protect building occupants.
What’s in Wildfire Smoke?
Wildfire smoke is far more than dirty air. It is a complex mixture of gases and microscopic particles that can negatively affect human health.
One of the greatest concerns is PM2.5—fine particulate matter measuring 2.5 micrometers or smaller. These particles are approximately 3% the width of a human hair and are small enough to travel deep into the lungs and, in many cases, enter the bloodstream.
Wildfire smoke may also contain:
- Volatile Organic Compounds (VOCs), including formaldehyde and acrolein
- Polycyclic Aromatic Hydrocarbons (PAHs)
- Carbon monoxide (CO)
- Nitrogen oxides
- Heavy metals and other contaminants released when structures, vehicles, and synthetic materials burn
When fires spread through developed areas, smoke becomes even more complex as building materials, plastics, and chemicals are introduced into the air.
How Wildfire Smoke Affects Building Occupants
Exposure to wildfire smoke can affect healthy individuals, but certain populations are at much greater risk.
Short-term exposure may contribute to:
Respiratory Effects
- Asthma attacks
- Coughing and wheezing
- Shortness of breath
- Reduced lung function
- Increased emergency room visits
Cardiovascular & Other Health Effects
- Elevated blood pressure
- Increased risk of heart attack and stroke
- Reduced cognitive performance
- Fatigue
- Blood sugar disruption for individuals with diabetes
Those at highest risk include:
- Individuals with asthma or COPD
- People with heart disease
- Older adults
- Pregnant individuals
- Immunocompromised employees
- Workers performing physically demanding tasks
Because most people spend nearly 90% of their time indoors, the quality of the air inside your building often has a greater impact on health than outdoor conditions.
Facilities Most at Risk
Wildfire smoke can affect nearly every type of commercial and institutional facility.
Organizations that should consider wildfire smoke preparedness include:
- Manufacturing facilities
- Healthcare campuses
- Schools and universities
- Commercial office buildings
- Warehouses and distribution centers
- Government facilities
- Municipal buildings
- Multi-family housing
- Data centers
- Industrial operations
Even buildings located hundreds of miles from an active wildfire may experience elevated indoor particulate levels during regional smoke events.
What a Wildfire Smoke Response Plan Should Include
In November 2024, ASHRAE released Guideline 44-2024: Protecting Building Occupants from Smoke During Wildfire and Prescribed Burn Events, providing new industry guidance for commercial, institutional, and multi-unit residential facilities.
A comprehensive Smoke Readiness Plan typically includes the following components:
HVAC Management
Reduce outdoor smoke infiltration by closing outdoor air dampers when appropriate, increasing air recirculation, and utilizing properly maintained MERV 13 or higher mechanical filtration.
Building Envelope Evaluation
Inspect doors, windows, loading docks, and other penetrations where smoke may enter the building. Proper building pressurization can also reduce infiltration.
Clean Air Spaces
Identify areas where sensitive occupants spend the most time and consider deploying portable HEPA filtration units to improve indoor air quality during smoke events.
Indoor Air Quality Monitoring
Real-time PM2.5 monitoring allows facility managers to determine whether smoke mitigation strategies are working effectively.
Communication Planning
Develop clear communication procedures so employees understand air quality conditions, response actions, and expectations during a smoke event.
Wildfire Smoke Readiness Checklist
Before the next wildfire smoke event, ask yourself:
✅ Do we monitor AirNow.gov or other AQI resources?
✅ Do we have a written Smoke Readiness Plan?
✅ Are our HVAC filters MERV 13 or higher?
✅ Can our HVAC system quickly reduce outside air intake when conditions warrant?
✅ Do we have portable HEPA filtration available?
✅ Do we monitor indoor PM2.5 levels?
✅ Have we identified occupants who may be especially vulnerable?
✅ Have we inspected our building envelope for smoke infiltration?
✅ Have we trained our staff on wildfire smoke response procedures?
If you answered “No” to several of these questions, your facility may benefit from additional planning before the next smoke event.
How IEA Can Help
For more than 40 years, IEA has helped organizations identify workplace hazards, improve Indoor Air Quality (IAQ), strengthen regulatory compliance, and protect building occupants.
Our Indoor Air Quality and Industrial Hygiene professionals provide practical, facility-focused solutions tailored to each organization’s needs.
Services include:
- Indoor Air Quality (IAQ) Assessments
- Wildfire Smoke Preparedness Evaluations
- PM2.5 Air Monitoring
- HVAC Ventilation & Filtration Assessments
- Smoke Readiness Management Plans
- Building Pressure & Airflow Evaluations
- Industrial Hygiene Consulting
- OSHA Compliance Support
- Employee Exposure Assessments
- Indoor Environmental Quality Investigations
Whether you’re preparing for wildfire season or responding to an active smoke event, IEA can help develop practical strategies that improve indoor air quality while protecting people, property, and operations.
Indoor Air Quality Services
Wildfire smoke is only one of many factors that can affect indoor air quality.
IEA provides comprehensive Indoor Air Quality (IAQ) assessments, industrial hygiene consulting, ventilation evaluations, mold investigations, exposure assessments, and environmental health services to help organizations create healthier indoor environments year-round.
👉 Learn more about our Indoor Air Quality (IAQ) Services.
Protect Your Building Before the Next Smoke Event
Wildfire smoke events are becoming increasingly common across Minnesota and the Upper Midwest. Having a proactive Indoor Air Quality plan can help reduce occupant exposure, improve building performance, and strengthen emergency preparedness.
