Rubbish floating in Naifaru Harbour, Maldives, Indian Ocean.Rosemary Calvert | Getty ImagesLONDON — A Tesla executive has left the electric car company and joined a London start-up that’s aiming to address the world’s plastic problem with a new chemical additive.Steven Altmann-Richer, who led public policy for U.K., Ireland and new markets at Tesla, joined London start-up Polymateria in the last few weeks as head of public affairs and regulatory strategy, after spending three-and-a-half years at the U.S. car company.Polymateria, which has around 25 staff based out of Imperial College’s start-up incubator, has developed a “biotransformation technology” that breaks down plastic into a wax-like substance that then gets digested by microbes. It has also created a new British standard for biodegradable plastic.”I want to help policymakers understand that this is a truly revolutionary solution which can improve the environment in their country and globally,” said Altmann-Richer, who holds a master’s degree in environmental policy from Oxford University, on a call with CNBC.The EU currently defines biodegradable plastics as those that can be composted at an industrial site. It doesn’t, however, take into account plastics that degrade by themselves in the natural environment and Altmann-Richer hopes to change this. “Previous technologies that have claimed to be biodegradable in the natural environment haven’t been,” said Altmann-Richer. “They’ve left the sort of microplastic beads behind, and therefore there’s been a lot of skepticism of that technology.”Polymateria is largely focused on the food packaging industry as it is one of the biggest consumers of plastic that ends up in the natural environment.Manufactured in France, Polymateria’s additive adds roughly 10%-15% to the overall cost of packaging. It also adds around 1%-2% of volume.The company, which raised a series A funding round of £15 million at a valuation of £110 million earlier this year, has signed deals with the likes of sportswear retailer Puma and plastics producer Clariant.