The plastic used to make older toys could pose a threat to children's health, according to the findings of a new study.
Old plastic toys – that have usually been passed down through generations of families, or donated to charity – could contain levels of toxic chemicals that can be hazardous to the health of children.
UK scientists from the University of Plymouth collected 200 plastic toys, such as trains, construction products and figures, from homes, daycare centres and charity shops in the South West of England.
What they discovered was high concentrations of "hazardous elements" that are toxic to children at low levels over an extended period of time. That would include a whole lot of sucking and biting over a couple of years of baby- and toddler-hood.
The elements present included antimony, barium, bromine, cadmium, chromium, lead and selenium.
"This is the first systematic investigation of hazardous elements in second-hand plastic toys in the UK," said lead author Dr Andrew Turner.
"Second-hand toys are an attractive option to families because they can be inherited directly from friends or relatives or obtained cheaply and readily from charity stores, flea markets and the internet."
Further testing under simulated stomach conditions revealed that some of the toys released bromine, cadmium or lead at levels exceeding the European Council's Toy Safety Directive. (In Australia, the maximum acceptable levels of "migratable lead" and other elements in children's toys and finger paints can be found on the Australian Competition & Consumer website).
The toys that contained the most chemicals were usually yellow, red or black. That's because toy manufacturers typically used chemicals containing cadmium or lead to create those colours.
Dr Turner told HuffPost UK it's hard to say how long it takes for a toy to accrue these chemicals.
"Toys made within the last decade are reasonably safe," he said. "It's the older ones that seem to be passed down through generations, but it is difficult to give a time scale.
"Parents should check the condition of the toy and avoid children putting them in their mouth – which I know is hard to ensure. They should also avoid brightly coloured red and yellow objects from the past.
"Cleaning doesn't do any good as the chemicals are within the plastic. These toys are generally safe to handle by hand, it's just when they start chewing them.
"If you want to be on the safe side, avoid using them. I guess the real danger is when they swallow them."
Here in Australia, CHOICE highlights that secondhand toys (along with mattresses, cots and car seats) can be risky for children. Parents should ensure pre-loved toys are in good condition with "no sharp edges or points, and no accessible batteries or strong magnets".
Consult a full checklist here
Find more information on toy safety at the Australian Toy Association