San Francisco just banned all polystyrene products in the ci

San Francisco has just unanimously voted to ban the sale of polystyrene products - also commonly called styrofoam - by 2017.

Polystyrene is the petroleum-based plastic foam that's used to make coffee cups, packaging peanuts, and a whole range of other disposable items. And though cities have begun cracking down on its use, this is the most extensive ban placed on the material in the US to date.

Although polystyrene is often better known to many people as styrofoam, that's actually just a trademarked brand name that only refers to the polystyrene foam used for thermal insulation and craft applications - not the polystyrene we use on a daily basis.

And to be clear, styrofoam insulation products won't be covered by these new rules, but they will ban the sale of all polystyrene food packaging, packing peanuts, take-away containers, coffee cups, foam dock floatings, mooring buoys, and pool toys as of 1 January 2017.

By 1 July 2017, it'll also be illegal to sell polystyrene fish and meat trays - like the ones you currently see in supermarkets. So it's a legitimate step towards San Francisco's goal of being a waste-free city by 2020.

It's been a long time coming, too. San Francisco first banned polystyrene take-away containers in 2007, due to environmental concerns. The plastic foam one of the most commonly used packing products, and 25 billion polystyrene cups are thrown out each year in the US alone.

Although the material is fairly soft, it's incredibly slow to break down in landfill, which means it'll be sitting there, leaching potentially harmful chemicals into waterways, for millennia to come. And there are also concerns that the material could impact human health by containing hormone-disrupting chemicals.

When polystyrene winds up in the ocean - which often happens to the 86 percent of disposable plastic that isn't recycled - it breaks down too quickly, and becomes microplastic that gets distributed through the water column, where it can be ingested by marine organisms, and concentrate toxins up the food chain.