TRADING Standards officers in Barnsley are warning businesses that it is now illegal to sell e-cigarettes to under 18s.
Anyone caught selling e-cigarettes to under 18s faces a fine of up to £2,500.
The new legislation makes it an offence for adults to buy e-cigarettes and tobacco products for children.
This also applies to liquid and capsule style refills.
Coun Roy Miller said: "Smoking is the single biggest cause of preventable death in Barnsley.
"Although current research suggests that e-cigarettes are significantly less harmful than smoking, I encourage anyone who uses either tobacco products or e-cigarettes to stop using them completely."