The latest peer-reviewed study from RLX Technology (RELX) published in the Journal of Applied Toxicology showed the cooling agent WS-23 widely used in e-cigarettes has limited impact on experimental animals at the tested dose.

The study showed that there were no deaths in any of the groups treated with the cooling agent in the acute and subacute inhalation studies, with no remarkable changes occurring in body weight, organ weight, hematology and serum biochemistry, and no toxic effects in histopathologic analysis.

It was the first study conducted by the Chinese e-cigarette industry to be published in a Science Citation Index (SCI) journal.

WS-23 is a well-known synthetic cooling agent widely used in food, medicine and tobacco. As a commonly cooling agent in e-cigarette liquids, WS-23 has led to concerns about the inhalation toxicity with the popularity of e-cigarettes in recent years. The study shows that at the tested dose level, inhalation of WS-23 will not bring toxic side effects to animals.

"Product safety has always been RLX's top concern, and it is also the direction and commitment in our research and development," said Xingtao Jiang, head of the RELX Lab. Before the study was published, RELX Lab conducted in-vitro tests to prove the aerosol containing WS-23 was safe to use in products. The latest assessment has further explored the inhalation toxicity of WS-23 used in the product. Jiang said RLX will continue to conduct more studies to improve the quality of RELX products.

The study was led by the RLX science team and part of the experiment was conducted in its physiochemical lab.

In September 2020, RLX announced its plan to conduct strict product quality, physiochemical pathological and clinical studies, and also evaluate the long-term use of e-cigarettes. The WS-23 study was the first publicly published scientific achievement.