Agrochemical Updates, eBulletin

Agrochemical update – temporary change to Ontario’s MRL for phosphorous acid

4 November 2022

Australian Grape & Wine recently announced that it has negotiated a temporary change to the Liquor Control Board of Ontario (LCBO) MRL for phosphorous acid.

This change means that the LCBO will accept Australian wines produced from vintages leading up to and including the 2023 vintage, provided that:

  • any phosphorous acid residues found in the finished, commercial wines imported by the LCBO are within the maximum residue level of 21 ppm expressed as phosphorous acid (or 30 ppm expressed as fosetyl-Al)
  • prior to export, prospective Australian exporters test their wines (that have been produced from grapes that have had phosphorous acid applied) to ensure compliance with the relevant MRL
  • exporters provide the LCBO with a copy of the relevant Certificate of Analysis, upon the LCBO’s request.

Exporters should note that the change to the LCBO’s MRL for phosphorous acid is temporary and subject to further review. Also, despite this temporary change, the relevant MRL in Ontario (and other major export markets) remains relatively low, and grapegrowers and winemakers should exercise care if intending to use phosphorous acid this growing season on grapes eventually destined for export.

The AWRI continues to recommend that growers engage with their grape purchasers or winery before making decisions on the use of phosphorous acid.

More information about phosphorous acid and export markets is available on the phosphorous acid page on the AWRI website and in the ‘Dog book’.

For further information on the export of Australian wine to Ontario, consult Wine Australia’s Export Market Guide – Canada or contact

For assistance with any technical grapegrowing or winemaking questions, contact the AWRI helpdesk on or 08 8313 6600.

For other enquiries
please contact
08 8313 6600