Composting Paper - Is it Safe?

by Debbie
(Corinth, MS)

I have a question about composting paper...You talk about using your shredded bills and cardboard in your compost pile. Do these processed papers contain harmful chemicals in them? Are they safe for use on your veggie garden when composted??

Thanks in advance for replies, Debbie.

Shredded Paper in the Compost

I'm a big fan of using shredded paper in the compost. I think it's a great high carbon compost material and most city and town dwellers have lots of it handy. But, Debbie asks a common question - are these papers and the inks they are printed with safe?

Is the Paper and Cardboard Safe?

Paper is usually made from pulp of various plants such as trees, rice, cotton, or hemp. The pulp is treated with various chemicals in the paper making process but once made they are pretty benign.

A lot of compost advice suggests avoiding glossy papers and colored inks. When I had my seed company I did a lot of printing. Our outside packaging was printed on a clay coated card stock. What made it glossy was the clay coat which is exactly that - paper coated with clay. When printed the coated paper tends to make the color more vibrant and glossy. Putting a skiff of clay into your compost is just fine - it is after all part of the soil.

But What About the Inks - Are They Toxic?

Some of the pigments used for printing inks used to be toxic. Non toxic substitutes have been in use for the last two decades or more. This is as much for workers health as it is for the environment.

Most of the inks are also now vegetable oil based. Usually it is soy oil. This was first used in the 70's when the first big oil crisis loomed. At that time the inks were in petroleum based solvents.

Those first soy based inks weren't a huge success and as oil became more available again the printing industry stepped back into doing the petro based solvents again. However, in the last decade or more the soy ink has become the standard and has proved to give very good quality printing.

Composting Paper - The Bottom Line

Given that many of us who live in towns and cities don't have an easy source of carbon rich straw for example composting paper makes sense. In fact the Sierra Club's Mr. Green says that one study showed that paper was actually less toxic than straw or grass clippings.

The microorganisms in the compost community are able to break down even petrochemicals. In fact the EPA has been doing tests for years and finding that composting soils contaminated with petrochemicals is a very effective way to rehabilitate some of the brown sites we have to reclaim.

Ironically Composting Paper is Safe But Do Be Careful with Grass and Straw...

Paper is safe but do be careful with grass and straw. Some fields and lawns have been treated with very persistent herbicides that don't break down in the compost process. You'll find more info on persistent herbicides here.

Composting paper, in my opinion and supported by the current facts about paper and printing, is safe.

Best Regards - Leslie