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Should shredded paper be composted?

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Dear Dig It!-

We shred paper bills at home to stop the deter identity theft. What should we do with the shredded paper? I’ve heard it can be composted but am concerned about the inks used on decades old paper in my parents' attic.       ~Scott

According to Alameda County Industries (ACI), the waste hauler serving the City of Alameda and parts of San Leandro, CA, they prefer to have the shredded paper placed in your curbside blue recycling cart. Loose shredded paper is captured on the single stream recycling sort line using a variety of screens that filter smaller materials or "fines." ACI suggests that you place shredded paper in a paper bag secured with one staple at the top before putting it in the blue cart. This practice prevents it from blowing off during collection and from getting contaminated during collection and processing by other recyclables and liquids.

Of course you could compost the paper in your backyard compost bin since it's a great source of carbon for compost critters, and helps balance nitrogen rich piles when you are composting lots of food. Shredded paper can also be used in smaller quantities in a worm bin or vermicomposting system to cover food scraps, prevent fruit flies and provide bedding for the worms.

However, the highest and best use of your shredded paper is to recycle it to be used again (most paper can be recycled up to 7 times). That said, when you shred paper, you're actually cutting the lengths of the individual paper fibers, which downgrades the potential and quality of the paper for future recycling. The length of a paper fiber determines its value since a longer fiber can be used to make a higher-grade paper and can be recycled more times. Most shredded paper is used for low grade paper products such as tissue, toilet paper, paper towels, etc.

If you have to shred paper consider the following tips to reduce paper shredding:

  1. Shred only the portions of the document containing sensitive or personal identity information, like the mailing label and account numbers, and keep the rest of the paper intact for recycling.
  2. Reduce unwanted mail or junk mail such as credit card offers and regularly update your business and personal mailing lists. For more information on reducing junkmail visit
  3. Go paperless. Consider signing up for e-billing or electronic statements, newsletters, etc.

As far as older paper that may have toxic ink I would say "dilution is the solution." Once your shredded paper is sent to a paper mill, the paper is turned into a pulp, screened for any contaminates like globs of glue or bits of plastic, cleaned to remove additional contaminates like staples, and then de-inked to remove printing ink and sticky residue (glue). The ink forms a froth which floats to the top leaving clean pulp behind. Fortunately, most of the inks being used today are vegetable-based inks which make the deinking process easier and the resulting froth less toxic. According to a study cited on the Natural Resources Defense Council website, "Less than one percent of the waste from a recycled paper mill is from ink, which is today more properly described as benign vegetable dye or carbon coated with plastic polymers; the remaining waste is water (90 percent) and short paper fibers (about 10 percent)".[See, for example, Bronx Community Paper Company in the Harlem River Yard, Final Environmental Impact Statement.]

Happy Recycling and Composting!