A number of Halloween masks found to be "extremely flammable" and which dropped molten plastic while burning have been seized from a shop in Gloucester.
The masks should be returned to the shop for a full refund
The Hypa Halloween Eva Scary Mask with Hood posed a very serious risk to children, Trading Standards said.
It was bought from Hyper Value in Northgate Street for £1. The store has now issued a nationwide recall notice.
The mask was discovered during a pre-Halloween check of novelty toys, including masks, capes and outfits.
Tests by the service's analyst confirmed that the mask was flammable and exceeded the limits set down in the Toy Safety Standards.
Officers seized the remaining stocks of masks from the Gloucester store. The range included masks with and without hoods. Further tests will be carried out on these products.
A Trading Standards official said the Hyper Value Group has co-operated fully with the investigation by promptly removing these items from sale and displaying recall notices in all its shops nationwide.
"We are extremely concerned that this mask poses a very serious risk to children. I would urge anyone who may have purchased one to return it immediately to the shop concerned for a full refund," he said.
The maximum penalty for breaching the Toy (Safety) Regulations 1995 is a fine of £5,000 and/or 6 months imprisonment.