Odorants may pose health risks at much lower exposure levels than currently suspected. 

Odorants are widely used in natural gas for leak detection and may induce a range of adverse health symptoms at very low concentrations including skin rashes, according to a new study in Current Environmental Health Reports.

“Our sense of smell is the first line of defense in detecting gas leaks, but few studies have examined how odorants in gas may adversely affect our health or well-being,” says the review’s lead author PSE Healthy Energy Senior Scientist Drew Michanowicz, in a news release. “The studies that do exist show potential risks, including evidence of both short-term self-reported health symptoms and longer-term health complications.”

The literature review examined 22 research articles related to the health hazards, risks, and impacts of five commonly used natural gas odorants. The researchers found that consistent symptom patterns were observed during odorant exposure in seven community-level exposure events and two occupational case reports. These findings suggest that odorants may pose health risks at much lower exposure levels than currently suspected. 

“Our findings indicate that while fairly little is known about the health risks from inhaling gas, they may be underappreciated,” adds Jonathan Buonocore, Assistant Professor at the Boston University School of Public Health. “Exposure to these intentionally added odorant compounds could represent an environmental justice issue for people living with a gas leak in their home, or frequently exposed to gas at work.”

The researchers include recommendations to improve the understanding and management of natural gas odorants, such as requiring chemical disclosure of odorants used in natural gas and establishing health-based exposure limits. More research is needed to better understand the causes of symptoms associated with odorant exposure, including effects on potentially susceptible populations or those that may exhibit some forms of odorant sensitivity or insensitivity.