SINGAPORE, Feb 6 (Reuters) - Polluting single-use plastic production rose globally by 6 million tonnes per year from 2019 to 2021 despite tougher worldwide regulations, with producers making "little progress" to tackle the problem and boost recycling, new research showed on Monday. But while growth has slowed recently, the production of single-use plastic from "virgin" fossil fuel sources is still nowhere near its peak, and the use of recycled feedstocks remains "at best a marginal activity", Australia's Minderoo Foundation said in its Plastic Waste Makers Index. See here for a complete list of exchanges and delays