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Pesticide Registration

PRN 82-1: Revised Policy on Label Claims for Tank Mixing

January 12, 1982

The Notice states: This notice announces that EPA has revised its policy for approving tank mix claims on pesticide labeling. This policy supersedes that contained in PR Notice 69-08, dated April 21, 1969.

On this page:
  1. Background
  2. Policy
  3. Relationship To Recommendations Made Under FIFRA Section 2(ee)
  4. Effective Date
  5. Further Information

  1. Background

    In the past, the Agency has required that applications for new registration or for amended registration involving claims for tank mixing the pesticide product with another pesticide product be supported by compatibility data and, if the mixture is to be used on a food or feed crop, by residue data demonstrating that the mixture would not result in residues higher than the tolerance established for each active ingredient. However, in cases where the pesticide labels are silent on the matter of tank mixing, applicators have been permitted to use tank mixes at their own risk if the sites or crops on which the mix is to be used are registered sites and crops for all the pesticides contained in the mix and if all pertinent limitations, use directions, and precautions are followed.

    Since years of reviewing compatibility and residue data for tank mixes and records of actual field experience have shown that as a practical matter potentiation is not likely to occur and that the resulting residues are within established tolerances, the Agency has revised its policy with respect to the requirements that must be met before label claims for tank mixes can be approved. This revised policy will significantly reduce the data generation burden on registrants as well as the review burden on the Agency and thus will allow more expeditious approval of registrations involving tank mix claims.

  2. Policy

    EPA will usually approve tank mix label claims without supporting compatibility and residue data if the following conditions are met:

    1. The site(s) or crop(s) for which tank mix claims are made are registered crops or sites for all pesticides recommended in the mix.

    2. The chemical characteristics of all products to be used in the mix are such that no incompatibility or potentiation is likely to occur. (The Agency reserves the right to request appropriate data if it determines that a problem could arise.)

    3. The pesticide product to be mixed with the product which is the subject of the application does not contain a label prohibition against such mixing.


    4. The label contains the statements: This product can be mixed with _______________ (chemical name, including percentage of active ingredient and type of formulation or specific product name, or both) for use on _______________ (crops/sites) in accordance with the more (most) restrictive of label limitations and precautions. No label dosage rates should be exceeded. This product cannot be mixed with any product containing a label prohibition against such mixing." Variations of these statements may be approved by the Agency. Where a specific product name is recommended for the tank mix, the label statements shall be more explicit, including such information as specific dilution and dosage rates.


    It should be noted that the addition of tank mix claims to labels still requires Agency review and approval prior to distribution. it should also be noted that although EPA will not as a rule require submission of efficacy, compatibility, or residue data to support tank mix claims, applicants and registrants should assure themselves that such tank mixes will not result in compatibility problems or residues in excess of tolerances.

  3. Relationship To Recommendations Made Under FIFRA Section 2(ee)

    On October 22, 1981, the Agency published in the Federal Register a policy stating that recommendations or advertisements for FIFRA section 2 (ee) uses may be made even though the pesticide product label is silent with respect to such uses (46 FR 51745). Of relevance to this notice is section 2(ee) (4), which states that it is not a misuse to mix a pesticide or pesticides with a fertilizer when such mixture is not prohibited by the labeling.

    The Agency wishes to clarify that this particular provision of the Act, as interpreted by the Federal Register notice, allows any person to make tank mix recommendations for use on crops or sites listed on the labels of both pesticide products regardless of whether or not the labels contain tank mix claims; however, in no case may tank mix recommendations be made for products containing label prohibitions against such claims. With respect to recommendations involving the dilution rate of the pesticides in the tank mix, the total amount of dilutent used must not be less than the amount required for the product requiring the higher rate of dilution. Recommendations for applying tank mixes for agricultural or forestry purposes at a dilution rate less than the higher of the label rates may be made only in accordance with the Advisory Opinion published in the Federal Register on March 3, 1981 (46 FR 14965).

  4. Effective Date

    This policy is effective immediately.

  5. Further Information

    Contact the Registration Division.

    Douglas D. Campt
    Registration Division (TS-767)

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