DENVER — Ozone generators remain one of the most effective tools available to restoration contractors for eliminating smoke and fire odors from structures, but their use requires strict safety protocols to protect workers, occupants, and pets from the health risks of ozone exposure.
Ozone (O3) is a powerful oxidizing agent that reacts with and neutralizes odor-causing molecules, including the volatile organic compounds produced by smoke, mold, and biological contamination. At sufficient concentrations, ozone can eliminate odors that are resistant to other treatments, including hydroxyl radical treatment and thermal fogging.
The Occupational Safety and Health Administration sets a permissible exposure limit for ozone of 0.1 parts per million over an eight-hour workday. Ozone generators used for odor elimination typically operate at concentrations of 1 to 10 ppm — far above safe occupancy levels.
Restoration contractors must ensure that structures are completely vacated — including all people, pets, and plants — before operating ozone generators, and must allow sufficient time for ozone levels to dissipate before re-entry. The IICRC recommends a minimum of two hours of ventilation after ozone treatment before re-entry.
New ozone generator models released in 2026 include built-in ozone sensors and automatic shutoff features that prevent operation if the unit detects a person or animal in the treatment area. These safety features are becoming standard on professional-grade equipment and are recommended by the IICRC and OSHA.
