The plastic used in many second-hand toys could pose a risk to children's health as they contain hazardous chemicals that do not meet the most up-to- date safety guidelines, scientists have warned.
They discovered high concentrations of elements including antimony, barium, bromine, cadmium, chromium, lead and selenium - which are chronically toxic to children at low levels over an extended period of time - in many building blocks, figures and items of jewellery that were typically either yellow, red or black.
A team from the University of Plymouth analysed 200 used plastic toys which they found in homes, nurseries and charity shops across the South West of England.
These included cars, trains, construction products, figures and puzzles, all of a size that could be chewed by young children.
Further tests showed that, under simulated stomach conditions, several toys released quantities of bromine, cadmium or lead which exceeded limits set by the European Council's Toy Safety Directive.
The research was led by Dr Andrew Turner, reader in environmental science, who used X-ray fluorescence (XRF) spectrometry to analyse the presence of elements within individual toys.
He said the research was the first of its kind and warned that the "attractive cost, convenience and recyclability of previously used toys has the potential to create a legacy of chemical contamination for younger children".
"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," he said.
"But while the Toy Safety Directive applies to new products, there is no regulation covering the recycling or re-sale of older toys.
"With the introduction and refinement of the Toy Safety Directive, the plastics industry has had to take steps to eliminate hazardous elements from new toys.
"However, consumers should be made more aware of the potential risks associated with small, mouthable and brightly-coloured old plastic toys or components."
The research is published in Environmental Science And Technology.