Established Maximum Residue Limit: Coumaphos

August 29, 2008
ISBN: 978-1-100-10523-9 (978-1-100-10524-6)
Cat. No.: H113-29/2008-18E (H113-29/2008-18E-PDF)
(EMRL2008-18)

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Under the authority of the Pest Control Products Act, Health Canada's Pest Management Regulatory Agency (PMRA) has registered CheckMite + Beehive Pest Control Strip, a new end-use product containing technical grade coumaphos, for use in honeybee colonies. The specific use approved in Canada is detailed on the product label of CheckMite + Beehive Pest Control Strip, Pest Control Products Act Registration Number 27147.

Corresponding maximum residue limits (MRLs) were proposed in the consultation document published on 26 February 2008, Proposed Maximum Residue Limit PMRL2008-01, Coumaphos. Appendix I summarizes the comments received during the consultation process and provides the PMRA's response to these comments.

To comply with Canada's international trade obligations, consultation on the proposed MRLs was also conducted internationally by notifying the World Trade Organization, as coordinated by the Standards Council of Canada. Appendix I summarizes the comments received during the World Trade Organization consultation process and provides the PMRA's response to these comments.

The comments received had no impact on the MRLs for honey and honeycomb which are established as proposed in PMRL2008-1.

The following MRLs are legally in effect as of the publication date of this document and are in addition to the MRLs already established for coumaphos.

Established MRLs for Coumaphos

Common Name:

Coumaphos

Residue Definition:

O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate, including the oxygen analog O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran- 7-yl) O,O-diethyl phosphate
(The chemical name for coumaphos was captured as "O-3-chloro-4-methylcoumarin-7-yl O,O-diethyl phosphorothioate". This has been revised to reflect Chemical Abstracts Service (CAS) nomenclature in accordance with the above table. In addition, the residue definition for existing livestock commodity MRLs was captured as parent only but has also been revised to include the oxygen analog as per the above table.)

Food Commodity / MRL parts per million (ppm)

Honeycomb / 0.1

Honey / 0.02

A complete list of all MRLs established in Canada can be found on the PMRA's MRL webpage.

Appendix I Comments and PMRA Responses

Comment

Two sets of comments were received, one from the PMRL consultation and the other from the World Trade Organization consultation, regarding the substantial difference between the MRLs proposed in Canada for honey and honeycomb (0.02 and 0.1 ppm, respectively) and the corresponding tolerances established in the United States (0.15 ppm and 45 ppm, respectively). These comments included a request to raise the proposed Canadian MRLs to reflect the American tolerances. There was also a question regarding the definition of "honeycomb", particularly in relation to "comb honey".

PMRA Response

The difference between the Canadian MRLs and the US tolerances arises from the difference in use patterns. According to the Canadian label, the honey supers cannot be replaced in the hive until 14 days after the Checkmite + Beehive Pest Control Strips are removed. The US label does not have such a restriction. The data reviewed to support the Canadian domestic registration of this product showed much lower residues. Therefore, the Canadian MRLs are much lower than the US tolerances and remain valid and are to be established as proposed.

The term "honeycomb" and "comb honey" appear to be interchangeable. In this case, "honeycomb" is the unprocessed commodity from the hive. This descriptor is consistent with that used by the United States in establishing their tolerances for coumaphos.

Comment

A third set of comments raised a number of questions and concerns related to the CheckMite + Pest Control Strip registration decision and the product label. It was also claimed that the coumaphos MRLs for livestock commodities were revoked in 2006 and that there was a need for MRLs to be established for other beehive products, including beeswax.

PMRA Response

Comments regarding the registration and label of CheckMite + Pest Control Strips are not related to the MRL consultation and are therefore not addressed herein.

MRLs legally established for coumaphos on livestock commodities remain in effect and have not been revoked. A complete list of all MRLs established in Canada can be found on the PMRA's MRL webpage.

Beeswax is considered as a food additive in Canada, and its levels in certain foods are regulated under the Food and Drugs Act and Regulations. Therefore, although residues of coumaphos in beeswax were non-quantifiable in the studies submitted to support the MRLs for honey and honeycomb, a new MRL will be proposed for coumaphos residues in or on beeswax. This will be consulted upon via publication of a new PMRL document.