The majority of gas- and propane-fired kitchens reached maximum temperatures above 90 degrees Fahrenheit. That exceeds the Occupational Safety and Health Administration’s stalled proposal of an 80°F indoor high-heat threshold, which would trigger 15-minute breaks every two hours. Galarza said he has experienced broiling temperatures greater than 130℉.
Nitrogen dioxide (NO2), a toxic byproduct of combustion that inflames the lungs and increases the risk of asthma, was also in the air. Seventy percent of fossil-fueled kitchens had NO2 concentrations that surpassed what’s considered safe by the Environmental Protection Agency and the World Health Organization. By contrast, electric kitchens had the lowest NO2 levels, never exceeding even a tenth of the WHO limit.
Gas stoves kept pumping out pollution even when turned off: About a third of fossil-fueled kitchens produced NO2 levels outside of business hours that exceeded health standards. The culprit was pilot lights.
“You have all these little fires going [in] the appliances overnight in the kitchen with the ventilation off,” said Drew Michanowicz, principal scientist at PSE Healthy Energy and a study co-author. In mixed-use buildings with restaurants on the ground floor, emissions could be migrating into nearby apartments.
“That pollution has to go somewhere,” Michanowicz said.
Carbon monoxide — a poison that can cause nausea, headaches, and disorientation — and benzene, a carcinogen known to raise the risk of leukemia, were also occasionally found at unsafe levels in some fossil-fueled kitchens. Electric kitchens again had the lowest levels of these compounds, and they stayed under safety guidelines.
“This study from PSE Healthy Energy makes clear that transitioning to fully electric kitchens can help protect the health of the people who work in them every day,” said Panama Bartholomy, executive director at the nonprofit Building Decarbonization Coalition. “We need policies, incentives, and other support that make electrification accessible to the industry.”
California currently leads the U.S. in policies encouraging commercial kitchens to electrify, according to the coalition. The state’s building energy standard requires new commercial kitchens be electric-ready, built with the wiring, outlets, and electrical capacity to allow kitchen owners to avoid having to make costly retrofits later. The Golden State has also created protections for indoor workers under heat stress, as have Maryland, Minnesota, Nevada, Oregon, and Washington, indirectly incentivizing all-electric kitchens. Utilities in California — and a few elsewhere — also offer rebates for more efficient commercial kitchen equipment, including electric options.
Galarza is seeing more chefs realize the other benefits of fossil-free appliances: the power, speed, and consistency of induction cooking; the reduced cleaning time and air-conditioning costs; and the improved mental health of workers, he said.
The new study’s results could catalyze the clean-cooking transition, Galarza noted. “The people who are bankrolling these kitchens — like the CFOs of these large hotel chains and these big conglomerate restaurants — those people need to understand what it is they’re putting their people in front of.”
