E-cigarette makers are adding potentially dangerous levels of the synthetic cooling agents WS-3 and WS-23 to disposable e-cigarettes and e-cigarette refills sold in the U.S., according to research published at the ATS 2022 international conference.

Mint and menthol-flavored e-cigarettes are highly popular due to their “cooling” effect. E-cigarette suppliers recently started marketing synthetic cooling agents as additives that have a cooling effect, but lack a “minty” odor. Yet, there is very limited knowledge about the content of synthetic coolants in e-cigarettes marketed in the U.S.—or about their health risks.