President Trump is due to tour a new petrochemical plant in Pennsylvania on Tuesday. The site, owned by Shell, is 30 miles northwest of Pittsburgh on the Ohio River. Once it’s fully up and running, it will create millions of tons of plastics every year, as well as 600 jobs. In the construction phase, up to 6,000 people are employed on site.

Many of our conveniences in modern life are made with plastics — they’re crucial for everything from keeping food fresh to helping make vehicles lighter-weight and more efficient. Much of it is recyclable, but not all.

Environmental experts say producing new, virgin plastic makes recycling even more difficult, because it puts pressure on the price and the economics don’t work out.