Karma cups have decided to no longer sell PLA (Polylactic acid or polylactide). We do not see PLA as a sustainable option, it will not decompose in your standard compost heap and we have found that many local authorities as yet have no way of dealing with it in commercial composting conditions.

 PLA can be recycled, but the infrastructure isn't in place as it is for a number of other plastics. If  you speak to plastic reprocessors, they really don’t want PLA in the waste stream. If the amount rises, they might have to look at rejecting whole batches of waste plastic.
In a recent article in letsrecycle.com, Lee Marshall, chair of the Local Authority Recycling Advisory Committee, said: 'It is difficult enough telling residents what bottles we want for recycling, it would be even worse if we were then saying 'and also these need to be put in the composting bin.”

You might think it could still be a good thing to put these materials in a landfill since they break down, but landfills and composts aren’t the same.

Materials buried in a landfill eventually break down, but they do so without oxygen. This anaerobic decomposition produces methane, a greenhouse gas that, according to the EPA, is  21 times more effective at trapping radiant heat than carbon dioxide. As a result, landfills are the fourth largest source of human-caused greenhouse gases.

Ideally in a well functioning compost system, materials break down aerobically (with oxygen), rather than becoming a contributor to the greenhouse gasses, they make a valuable soil enhancer but not PLA.

Our other concern is that PLA is made from genetically modified maize, even though no genetic material remains in the end product we feel this is not a sound sustainable practice and also have some ethical concerns selling products made from wheat or corn, that should be used for food, rather than to produce packaging materials.