Laser hair removal offers the convenience of eliminating unwanted hair with a relatively easy procedure.

It’s an attractive prospect: Who wouldn’t like to spend less time shaving and less money on those expensive razors? But laser hair removal comes with a newly discovered, and potentially undesirable, exposure.

Researchers writing in the journal JAMA Dermatology note that the smoke produced when a laser burns away a patient’s hair contains dangerous chemicals. According to the findings, patients and laser hair technicians are exposed to 13 known or suspected cancer-causing agents in just 30 seconds of hair removal, along with numerous other chemicals that are considered environmentally harmful.

Laser hair removal works by targeting the hair inside its follicle, which is a tiny bed in the skin where an individual hair grows.

The laser can only treat an area of skin about the size of a quarter at a time, which can make covering a large area of the body quite time-consuming. Likewise, numerous sessions are needed for each area of the body to show real results.

All this makes for a good bit of laser work, and a lot of exposure to unhealthful fumes, to achieve a hairless look. The researchers from the University of California, Los Angeles, found that even with an air-exchange system, there was an eight-fold increase in airborne concentrations of potentially harmful particles compared with room air before the procedure. With the air-treatment system turned off, the level of harmful particles jumped to 26 times the pre-treatment level.

While the researchers note that more study is needed to determine the effect of such exposures, even the most dedicated beauty mavens may think twice and keep their razors.