New York City Mayor Michael Bloomberg is to propose a ban on Styrofoam.

The substance is commonly used for take-away food containers and is almost impossible to recycle.

The mayor, who has already targeted fat, sugar and salt in the city, says the foam clogs up landfills, does not biodegrade and might harm human health.

Mr Bloomberg will raise the proposal in his final State of the City speech today.

In his 12th year as mayor, he made public health and sustainability hallmarks of his three terms in office, and he has taken aim repeatedly at the fast-food industry.

Most recently, he had a controversial plan to bar the sale of large portions of sugary fizzy drinks, which goes into effect next month.

Styrofoam, he says, should go the way of lead-based paint, which the city banned from residential use in 1960.

An estimated 20,000 tonnes of Styrofoam enter the city's waste stream each year.

It can add an estimated $20 per tonne to the cost of recycling, because it needs to be removed from the recycling stream, the city said.

Similar bans have been adopted in Los Angeles, San Francisco, Seattle and Portland, Oregon.

The plan was likely to meet opposition from small businesses, since alternatives to Styrofoam tend to cost between two and five times as much.

While Mr Bloomberg's aggressive campaigns have won him plaudits from some, others have dubbed him a "nanny" mayor and said his ideas limit choice and pre-empt individual responsibility.

During his first term, he pushed through a ban on smoking in bars and restaurants.

Despite an initially rocky reception from New Yorkers, it is now enormously popular and has inspired similar bans in cities and countries around the world.

Next was a ban on trans fats and a dictate that fast-food restaurants post calorie information in large type on menu boards.

Last year, he said restaurants and takeaway food shops could no longer sell sugary drinks larger than 16 ounces (47cl).

The soft drinks industry is challenging that ban, calling it an unconstitutional overreach that burdens small businesses and infringes upon personal liberty.