SAN FRANCISCO — San Francisco residents will not be able to buy polystyrene foam coolers, coffee cups, kiddie pool toys, or packing materials under a measure approved by supervisors in June that goes far beyond the prohibition on foam food carryout containers in effect in dozens of cities.

Environmentalists are cheering the ban as the most comprehensive by a large US jurisdiction on the cheap insulating foam that cushions goods and keeps drinks hot or cold. They say the lightweight plastic is extremely slow to decompose, and it pollutes waterways, harming marine life and birds.

The ban on the retail sale of foam goods becomes effective Jan. 1. The prohibition on meat and fish trays used by local food retailers will take next July.

Detractors say the legislation does nothing to stop foam-wrapped goods that are shipped into the city, defeating San Francisco’s stated purpose of reducing waste. They would rather San Francisco recycle the product.

What’s formally known as ‘‘expanded polystyrene’’ is the latest plastic to be targeted by cities,much like the single-use plastic bag, which San Francisco outlawed in 2007.

The San Francisco measure builds off a 2006 ordinance mandating food vendors and restaurants use recyclable or compostable carryout containers. Cities such as Seattle, Los Angeles, and Portland, Ore., followed suit.