New CCME Guidelines for Compost Quality Announced October 2005

The Canadian Council of Ministers of the Environment (CCME) Guidelines for Compost Quality was originally published in 1996. The Compost Guidelines focus largely on compost quality and can apply whether the compost is sold or given away. They define two Classes of compost: A (unrestricted use) and B (restricted use).

The compost is defined by four sets of criteria:

• foreign matter,
• maturity,
• disease-causing organisms, and
• trace elements.

A revision process was launched in 2003 to keep the guidelines consistent with changes being considered for the BNQ standard (see below). The revised CCME Guidelines were announced October 13, 2005. The major changes are:

Trace elements : Allowable limits for copper and zinc have been increased for Class A compost. These are both plant nutrients. The changes allow manure composts to be included in the Class A category. All measurements refer to dry weight.

Copper: was 100 mg/kg, now 400 mg/kg

Zinc: was 500 mg/kg, now 700 mg/kg

Maturity : The original CCME Guidelines included a long, and somewhat confusing, list of maturity criteria. The revised edition states that finished compost must be cured a minimum of 21 days and meet one of the three following requirements:

• an oxygen uptake of 400 milligrams or less per kilogram of compost per hour
• a carbon dioxide release rate of 4 milligrams or less of carbon, (as carbon dioxide) per gram of compost per day
• compost temperature is less than 8°C above the surrounding environment

The provinces and territories hold the responsibility of regulating the disposal and beneficial use of wastes on land, including the production and use of compost. The CCME provides a means of working together on these and other issues of common concern.

Two other national bodies work cooperatively with the CCME to maintain standards and guidelines for compost quality in Canada:

Canadian Food Inspection Agency (CFIA) regulates compost when it is sold as a soil amendment or a fertilizer with a guaranteed nutrient content.

Bureau de normalization du Quebec (BNQ), an agency acting on behalf of the Standards Council of Canada, sets voluntary industry standards.

Provinces or territories can choose to adopt the Compost Guidelines as official regulations. That step has not yet been taken in Saskatchewan because of the relatively low number of composting operations.

Copies of the Guidelines for Compost Quality can be viewed on-line, or puchased (see PN 1340).

(Source: March 2006 WasteWatch)

Back to Composting main page

Back to Resources main page

Back to Home page