Tank mixing, a practice commonly performed by growers across the agricultural spectrum, is an important practice used to reduce the number of sprayer passes per season, prevent resistance development, and to improve product performance.

 

Health Canada’s Pest Management Regulatory Agency (PMRA) recently announced clarifications to the tank mixing policy in a new guidance document on December 22nd, 2022, entitled “PMRA Guidance Document Tank Mix Labelling”.

 

Previously, products could be tank mixed if there were no restrictions on any of the partner labels. Under the updated policy, a tank mix can only be applied if the partner labels specifically allow tank mixing. This could appear on the label in one of two forms given below. Additional instructions such as mixing order, or instructions for performing compatibility testing such as the jar test method may also be included in these statements.

 

Option 1: The label specifically identifies permitted tank mix partners (e.g., “Product X may be tank mixed with products A, B, and C” …); OR

 

Option 2: The label includes a general tank mixing statement (see below) which permits tank mixing as long as both tank mix partner labels include the statement. Note that product labels may contain both the general tank mixing statement and a specific list of tank mix partners.

 

“This product may be tank mixed with (a fertilizer, a supplement, or with) registered pest control products, whose labels also allow tank mixing, provided the entirety of both labels, including Directions For Use, Precautions, Restrictions, Environmental Precautions, and Spray Buffer Zones are followed for each product. In cases where these requirements differ between the tank mix partner labels, the most restrictive label must be followed. Do not tank mix products containing the same active ingredient unless specifically listed on this label.

 

In some cases, tank mixing pest control products can result in reduced pesticide efficacy or increased host crop injury. The user should contact [insert registrant name] at [insert contact information] for information before applying any tank mix that is not specifically recommended on this label”.

 

PMRA’s generic tank mixing label statement as per Tank Mixing Labelling Guidance Document 2023.

 

It is also important to note that some product labels might have an exclusionary statement that specifically does not allow tank mixing (e.g., Do not mix or apply this product with any additive, pesticide or fertilizer except as specifically recommended on this label). If a product’s label contains this type of exclusionary statement, then it can only be tank mixed with the specific tank mix partners appearing on its label. To help guide interpretation of the label statements related to tank mixing, the guidance document includes a table to describe various scenarios and whether or not tank mixing would be allowed (see table 1 below).

 

Table 1: Permissibility of tank mixing based on various combinations of label statements related to tank mixing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*There may be registered labels that have tank mix scenarios like this. Note that this is not allowed for new tank mix label amendments. Further, any product labels that have tank mix scenarios like this must be amended to alleviate the contradictory scenario. To do this, using the last scenario in Table 1 as an example, one of the following must occur: 1) remove the Product X tank mix from the Product Y label, 2) remove the exclusionary statement from the Product X label, or 3) add a specific tank mix for Product Y on the Product X label. Source: PMRA Guidance Document Tank Mix Labelling 2023

 

Registrants are required to update their labels to align with these changes within two years of the publication date of the guidance document (i.e., by December 22, 2024). Likewise, according to a March 17, 2023, update to the guidance document, sprayer operators can continue their current tank mix practices during the two-year transitional period. On December 22, 2024, the PMRA policy will be in full effect; All practices, labels, marketing materials and educational materials must then be consistent with the new policy.

 

For growers, and other users of pest control products, this effectively means they may continue to tank mix as previously done for the 2023 and 2024 field seasons. However, when ordering and purchasing product in late fall 2024 and winter 2024-2025, users will need to ensure that desired tank mix partner labels permit tank mixing with each other to ensure their pest control product sprays applied in 2025 comply with the new guidelines.

 

Parties affected by this new policy change are encouraged to review the guidance document in its entirety for a full explanation and further detail on these changes. For any outstanding questions you may have regarding these new guidelines after reviewing the guidance document, please contact the PMRA Info Service at pmra.info-arla@hc-sc.gc.ca. Further information on tank mixing practices can also be found on the Sprayers101 website.