Trading standards officers in Wolverhampton have issued the warning due to a growing trend of people buying dummy chains, which have been decorated by people at home and then sold via the internet.
While the original individual pieces may adhere to safety regulations, concerns have been raised about the chains once they have been decorated and assembled.
These concerns include gem stones becoming detached and swallowed by children, the glue or paint applied being potentially toxic and hygiene issues with the jewellery.
Officers have been visiting children's centres across the city to highlight the dangers these custom-made dummies could pose to babies and young children.
If people do modify dummies then it is their responsibility to ensure they are safe before they are sold.
Councillor John Reynolds, Wolverhampton City Council's Cabinet Member for City Services, said: "While selling custom-made 'dummy chains' is not illegal we want people to ensure they are safe before they do so.
"There are genuine concerns that these items could pose a serious risk to babies and young children, which is why our Trading Standards officers have been out to visit parents at children's centres to highlight these dangers.
"I would urge anyone who does modify these chains to get them checked for safety or contact our Trading Standards team for advice."
Trading Standards also carry out talks to schools and community groups about consumer's rights and how to deal with faulty and misdescribed goods and services. If you would like a visit from a Trading Standards Officer then please call and book a talk.
People can contact Trading Standards on 01902 551155.
- released: Thursday 2 May, 2013