Braskem, Brazil’s leading petrochemical producer, and Dow Chemical’s local subsidiary each have announced plans to make polyethylene, a plastic commonly used in packaging, from sugarcane-based ethanol.

The companies tout the product as far more eco-friendly than conventional polyethylene, which is made from oil-based naphtha, because its production involves dramatically lower carbon-dioxide emissions.

Though the technology to make ethanol-based polyethylene has been around for 30 years, only now do economic conditions favor putting the process to large-scale use, experts say. That’s the case in part because the local ethanol supply is growing to serve Brazil’s fast-expanding fleet of flex-fuel cars, which run on gasoline or ethanol and account for 90% of new cars produced here. Brazil is the world’s second-ranking ethanol producer after the United States and the world’s leading exporter.

Also aiding the economics of ethanol-based polyethylene are declining ethanol-production costs and rising prices for the oil needed to make naphtha.