Most paper materials are compostable
PPEC pioneered the composting of paper packaging materials in North America back in the early 1990s. The initiative then was to divert certain perceived “problem materials” from landfill (waxed corrugated and old boxboard) but PPEC quickly recognised that composting was an option for all paper materials that ended up far from the appropriate recycling mill. It did not make sense, environmentally or economically, to ship materials hundreds of kilometres to the closest recycling mill (just so one could say they had been recycled) when composting was an option locally, and a job creator, especially on the Prairies and in the Maritimes.
PPEC commissioned pioneering trials on waxed corrugated and old boxboard at the Macdonald farm campus of McGill University in Sainte-Anne-de-Bellevue, Que., with commercial trials on old boxboard following in Milton, Ontario. Both trials indicated that an appropriate ratio of carbon to nitrogen could be reached to produce acceptable compost.
Today, Prince Edward Island composts all its old boxboard, and Nova Scotia composts more old boxboard than it sends for recycling.
While the focus of governments and industry in the early 1990s was primarily on packaging waste, there was a growing awareness of other waste streams that needed to be addressed, including leaf and yard waste, and organics. And this is where the kraft paper bag has come into its own.
Leaf and Yard Waste Bags
Typical yard waste bags are square-bottomed so they stand up without support for easy filling with plant cuttings, leaves and/or grass.
They allow the contents to “breathe” so they don’t produce odours or attract rodents. But the beauty of the paper yard bag is that is composts along with the contents of the bag. A municipality or private sector contractor does not need to spend scarce dollars on expensive de-bagging machinery or labour costs such as those incurred when using yard bags made of plastic. The smallest traces of plastic in compost downgrades or renders it useless, so a growing number of municipalities avoid the risk and cost from the beginning by choosing paper. A list of Canadian towns and cities using paper yard bags can be found to the right of this section.
Food Waste Bags and Liners
Food scraps or kitchen organics are a major component of the residential waste stream (about 30%). This fact has encouraged municipalities to promote backyard composting by individual homeowners (sometimes subsidising the sale of composting bins) or to build themselves or contract out to centralised composting facilities. So what’s the best way to get the “yuck” stuff from the house to the curb, and from the curb through to the end result (good compost)?
Paper food bags and bin liners are one answer. The bags normally have a cellulose (non-plastic natural fibre) liner that makes them leak-resistant and odour-free when sealed. The smaller bags can stand alone, fit neatly in a bin under the kitchen sink, or hang from a wire basket inside the cupboard door. They can later be placed into a bigger bag or a municipal “green bin” for collection and pick-up. The larger bags can also be used as a liner for the green bin (keeping it clean).
What’s required to make good compost?
Good compost requires the right balance between carbon and nitrogen to promote the active decay of organic matter. Since paper bags are made from carbon (cellulose) all that’s needed is the appropriate proportion of nitrogen (which food scraps provide). For a bag to claim compostability in Canada, it must disintegrate by at least 90% within 84 days of the composting process; biodegrade by at least 90% within 180 days; and have no ecotoxicological effect greater than 10% on the germination rate of seeds and vegetation biomass rate1. Any claim of compostability must also indicate how widely consumers have access to composting in the area where the bags are distributed2.
Several paper companies (including Bag to Earth) have chosen to have their bags third-party certified as environmentally preferable under the Eco Logo label.
Bags that meet the Eco Logo standard demonstrate reduced resource depletion and toxic emissions, combined with sustainable forestry practices3. Most paper yard bags are high in recycled content and third-party certified for responsible sourcing of the materials used to make the bags.
1 Composting Council of Canada www.compostable.info
2 An unqualified claim of compostability requires that at least 50% of the population in the area where the bag is marketed must have access to its collection for composting. If this is not the case, claims must be qualified with much greater geographic detail printed on the bag. See Environmental claims: A guide to industry and advertisers, developed by the Canadian Standards Association (CSA) and the Competition Bureau. http://www.competitionbureau.gc.ca/eic/site/cb-bc.nsf/eng/02701.html
3 Environment Canada’s Environmental Choice (Eco Logo) Program has developed a national certification criteria document on Compostable Paper Bags (CCD-087). For technical details, click here