Factbox - Wheeler dealers: how to make money from scrap tyres

Workers operate furnaces at a tyre pyrolysis plant in Kulai, Johor, Malaysia August 7, 2019. Picture taken August 7, 2019. REUTERS/Edgar Su

SINGAPORE (Reuters) - International trade in waste tyres has almost doubled in the past five years, according to data provided by customs departments to the United Nations, generating millions of dollars in business across the supply chain.

The biggest, and fastest growing, trading route is from Britain to India, where authorities are increasingly worried about the dirty business of turning waste rubber into oil - a process called pyrolysis.