The U.S. Environmental Protection Agency (EPA) has updated air pollution standards to further control toxic air emissions from petroleum refineries.

EPA says that exposure to toxic air pollutants, such as benzene, can cause respiratory problems and other serious health issues and can increase the risk of developing cancer. The rule requires first-of-its-kind fenceline monitoring. It also seeks to strengthen emission controls for flares, pressure relief devices, storage tanks, and delayed coker operations.

The agency says that when fully implemented, the rule will result in a reduction of 5,200 tons per year of toxic air pollutants, and 50,000 tons per year of volatile organic compounds (VOCs). EPA projects that these standards will eliminate emissions of greenhouse gases equivalent to approximately 660,000 tons per year of CO₂. EPA claims that the rules will have "no noticeable impact" on the cost of petroleum products at the approximately 150 petroleum refineries around the country.

The EPA's regulatory action requires continuous monitoring of benzene concentrations at the fenceline of refinery facilities to ensure that refineries appropriately manage toxic emissions. The rule requires corrective action to protect neighboring communities from being exposed to harmful levels of emissions if the established standard level is exceeded. Fenceline monitors must encircle the facility to detect benzene at very low levels, and the monitoring data will be posted on EPA’s website. In addition, EPA says that in response to public feedback, the rule provides room for alternative monitoring methods in the future as technology advances.

EPA says that other requirements in the rule will virtually eliminate visible flare emissions and releases by pressure release devices by requiring a comprehensive program of process changes and pollution prevention measures. The rule will also require additional emission reductions from storage tanks and delayed coking units.