The jet stream is carrying smoke and toxic air from recent wildfires in Canada into the United States—particularly the Northeast and Mid-Atlantic states, but also into the Midwest. Haze and hazardous conditions resulting from the fires, which are fueled by rising temperatures and drought, have led some contractors to give workers the day off when air quality is especially poor.

Neither the Environmental Protection Agency nor the Occupational Safety and Health Administration has issued a mandate regarding work stoppage. However, in early June, OSHA issued a recommendation to employers to monitor air quality conditions and to reduce workers’ exposure to wildfire health hazards, including smoke.

“Wildfire smoke exposure can create major health hazards for outdoor workers,” said Assistant Secretary of Labor for Occupation Safety and Health Doug Parker. “These hazards can be reduced with knowledge, safe work practices and appropriate personal protective equipment.”

With more than 630 active wildfires in Canada as of July 4, 2023—over 300 of which are deemed out of control—and more than 8.5 million acres burned, according to the Canadian Interagency Forest Fire Centre, air quality is likely to be a long-term concern.

The biggest hazard related to wildfire smoke is exposure to particulate matter. Particles of partially burned material measure less than 2.5 micrometers in diameter and can enter the lungs and the blood stream. They’re capable of causing health problems such as lung, heart or kidney disease. Exposure can also lead to heat stress, as well as eye and respiratory tract irritation.

OSHA’s advice to reduce outdoor workers’ exposure to hazardous air includes:

• Frequent monitoring of air quality conditions using a source such as the EPA’s AirNow
• Relocating or rescheduling work tasks to smoke-free areas
• Reducing levels of physical activity, especially strenuous and heavy work
• Requiring and encouraging workers to take breaks in smoke-free places when possible
• When possible, making accommodations for employees to work inside with proper HVAC systems and high-efficiency air filters
• Providing or allowing the use of NIOSH-approved respirators for voluntary use, when not otherwise required. When allowing respirators for voluntary use, employers must provide employees with the advisory information in Appendix D of OSHA’s Respirator Protection Standard.

While contractors have generally been generous in allowing accommodations for outdoor workers when air quality is poor, most, like the New York City Department of Buildings, have not issued a halt on construction. To protect workers from exposure to toxic air, Scott Smith, vice president of risk control services at Branchville, N.J.-based Selective Insurance, suggested:

• Deviate the work schedule to temporarily shift workers to indoor work.
• For indoor work, keep all windows closed and only run air handling systems with mechanical filtering.
• Look to reduce the length of work shifts and to reduce physically demanding work that requires higher breathing rates. 
• Educate workers about wildfire smoke hazards and encourage them to speak up if air quality or symptoms worsen.
• Offer NIOSH-approved respirators, such as N95 masks.

NECA has also provided a list of resources for additional information on dealing with hazardous air.