Information and Notification Document on Health Canada's Proposal to Enable the Use of Dimethyl Dicarbonate as a Preservative in Wine and in Unstandardized Water-Based Non-Alcoholic Beverages

October 25, 2012

Summary:

Health Canada received a food additive submission seeking approval for the use of dimethyl dicarbonate (DMDC) as a preservative at a maximum level of use of 250 parts per million (ppm) in various unstandardized water-based non-alcoholic beverages and at a maximum level of use of 200 ppm in wine. Unstandardized water-based non-alcoholic beverages includes such products as ready-to-drink teas, fruit-flavoured sport drinks, energy drinks, and carbonated flavoured soft drinks.

The results of Health Canada's evaluation of the available scientific data support the safety and efficacy of DMDC when used as requested. Therefore, it is the intention of Health Canada to amend Part 3 of the List of Permitted Preservatives by adding the following entry to the list:

Rationale:

Health Canada's Food Directorate has completed a pre-market safety and efficacy assessment of DMDC used as described above. The assessment considered microbiological, toxicological, and technical aspects of the proposal.

Although the growth of all microorganisms would not be controlled by this chemical, for example certain types of heat- and baro-resistant ascospores of heat-resistant moulds, Health Canada's Food Directorate has concluded that the data provided demonstrate the efficacy of DMDC against yeast, some types of fermentative spoilage bacteria such as Lactobacillus, and moulds, including heat-resistant fungi that could survive pasteurization treatment. In addition, when DMDC is used in wine, the amount of any added sulphite (which is already permitted in wine as an antimicrobial preservative) can be reduced, since the synergistic effect of sulfites and DMDC against bacteria and yeast has been demonstrated in wines of different acidity.

DMDC exerts its technical effect immediately after addition to the beverage or wine by inactivating microbial enzymes, but it is hydrolyzed to methanol and carbon dioxide after several hours. Therefore, since there is no dietary exposure to DMDC, potential exposure to substances formed from the hydrolysis of DMDC was considered. Scientists within Health Canada's Food Directorate utilized Canadian food intake figures and took into consideration other potential dietary sources of these substances to develop its exposure assessment. It was determined that the low level of exposure to these hydrolysis products as a result of the use of DMDC would not be of toxicological concern.

Health Canada's Food Directorate also reviewed the potential exposure to an impurity in DMDC and possible reaction products that could form when DMDC is used in beverages. No toxicological concern was identified for the very low levels of these substances that might be present in beverages from the use of DMDC as a preservative.

Based on the results of the safety assessment, Health Canada's Food Directorate scientists consider that the data demonstrate the safety in use of DMDC under the requested conditions of use, that is, 250 ppm in unstandardized water-based non-alcoholic beverages and 200 ppm in wine. The Department is therefore proposing to enable the use of DMDC as described in the above table.

Other Relevant Information:

• Given that one of the proposed areas of use is wine, for which there is a compositional standard (section B.02.100 [S], Division 2 of the Food and Drug Regulations), a targeted consultation on the acceptability of the proposal was carried out with the Canadian Vintners Association (CVA). The CVA found no objections to the proposed use of DMDC in wine among its membership.
• The proposed use of DMDC is consistent with the international Codex General Standard for Food Additives, which includes entries for the use of DMDC in "water-based flavoured drinks", including "sport," "energy," or "electrolyte" drinks and "particulated drinks" to a maximum of 250 mg/kg; and in "grape wines" to a maximum level of 200 mg/kg.

Contact Information:

For additional information or to submit comments related to this proposal, please contact:

Bureau of Chemical Safety
251 Sir Frederick Banting Driveway
Tunney's Pasture, PL: 2203B
Ottawa, Ontario K1A 0L2

E-mail to: bcs-bipc@hc-sc.gc.ca

When communicating by e-mail, please use the words "dimethyl dicarbonate" in the subject box of your e-mail. Health Canada is able to consider information received by December 23, 2012 at 11:59 p.m. EDT, 60 days from date of this posting.