Mayor Bill de Blasio announced Thursday that he has signed an executive order requiring city agencies to stop buying “one-use” plastics, such as plates, utensils and straws, and replace them by the year’s end with “compostable” materials.

There would be exemptions, mostly for people with disabilities.

The ban will result in a less than 1% reduction in the amount of single-use plastic foodware that ends up in landfills every year, since most comes from households.

“We have to do it in stages,” de Blasio said at the Sims Municipal Recycling center in Brooklyn. “These actions by New York City are helping other people to act.”

The mayor said he anticipates the cost of the switch will be minimal.