Cooling chemicals in vapes: WS-23, WS-3 and WS-5

5th October 2026

Why we’re flagging this: Some vapes contain chemicals that make the vapour feel cold or icy. New research has raised concerns about three of these chemicals: WS-23, WS-3 and WS-5.

Last checked: 5 October 2026

What’s happening?

Germany’s Federal Institute for Risk Assessment has reviewed cooling chemicals used in e-cigarettes. It says WS-23, WS-3 and WS-5 may pose health risks at the levels it looked at, particularly with regular use of products containing higher amounts.

The agency found at least one of the cooling chemicals it studied in more than 176,000 products registered in European market data. More than 60,000 contained more than one cooling chemical.

Earlier research has found WS-23 and WS-3 in vapes, including some products that did not use words such as “ice” or “cool” on the packaging.

Why does this matter?

Cooling chemicals can make vapour feel smoother, colder or less harsh. They may appear in mint, fruit, sweet and other flavours.

This does not mean these ingredients are suddenly common in Wales. It is a new research finding that is worth watching.

What don’t we know yet?

We do not know how common WS-23, WS-3 or WS-5 are in vapes sold or used in Wales. We also do not yet have good long-term evidence on breathing in these chemicals.

The German recommendations are not new UK law.

What should parents, schools and communities look out for?

Vapes described as “ice”, “cool”, “frost” or similar. These words do not prove a particular cooling chemical is present.
Ingredient lists that mention WS-23, WS-3 or WS-5.
Unfamiliar or unregulated vapes where the contents are unclear.

Do not open, taste or test an unfamiliar vape. If someone becomes unwell after vaping, seek appropriate medical help.

Sources

Share this story

Writing about this issue?

Journalists can use the ASH Wales Media Centre for Wales-specific data, background and spokesperson requests.

What's New?