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Consumer Product Safety

Incident Report

Subform I: General Information

1. Report Type.

New incident report

Incident Report Number: 2024-0077

2. Registrant Information.

Registrant Reference Number: M-782675-01-1

Registrant Name (Full Legal Name no abbreviations): BAYER CROPSCIENCE INC.



Prov / State: AB

Country: CANADA

Postal Code: T2C 3G3

3. Select the appropriate subform(s) for the incident.

Scientific Study

4. Date registrant was first informed of the incident.

5. Location of incident.

6. Date incident was first observed.

Product Description

7. a) Provide the active ingredient and, if available, the registration number and product name (include all tank mixes). If the product is not registered provide a submission number.


PMRA Registration No. 19204      PMRA Submission No.       EPA Registration No.


  • Active Ingredient(s)

7. b) Type of formulation.

Application Information

8. Product was applied?


9. Application Rate.

10. Site pesticide was applied to (select all that apply).

11. Provide any additional information regarding application (how it was applied, amount applied, the size of the area treated etc).

To be determined by Registrant

12. In your opinion, was the product used according to the label instructions?


Subform VII: Scientific Study

1. Study Reference

Title Lemna gibba G3 - Growth inhibition test with Phenmedipham TC under semi-static conditions

Date 08-DEC-21

2. a) Is an extension needed to translate the document?


3. Type of incident identified in the study

Increased health or environmental risk

4. Describe the incident identified in the study (e.g. study demonstrates an increased risk to non-Hodgkin's Lymphoma after exposure to pesticide X)

The active substance, phenmedipham, was tested on Duckweed (Lemna gibba) for 7 days in a semi-static exposure system to nominal concentrations of: 0 (control) and solvent control (dimethylformamide at 0.1 AuL/mL), 0.200, 0.633, 2.00, 6.33, 20.0, 63.3 and 200 Aug a.s./L (corresponding to geometric mean-measured concentrations of 0.131, 0.388, 0.963, 3.10, 11.6, 44.6 and 163 Aug a.s./L). Treatment endpoint inhibition levels were compared to the pooled controls. Test conditions met all guideline validity criteria. The 7-day ErC50=33 Aug a.s/L (95% C.L. = 31.1 to 35.9 Aug a.s./L), was based on mean growth rate of frond numbers, and the 7-day ErC50=69.3 Aug a.s/L (95% C.L. = 62.2 to 77.5 Aug a.s./L), was based on mean growth rate of plant dry weight. These values were lower than the current Lemna minor EC50 value of 160 I 1/4g a.i./L that is considered in the risk assessment and thus would meet the criteria for adverse effects reporting. [Scheerbaum, D.; (1998) Phenmedipham: Substance Technical: 98.5% w/w: Code: AE B038584 00 1D98 00: Lemna minor: Semi-Static Phytotoxicity Test..; MRID 49682516].

5. a) Was the study discontinued before completion?


5. b) Provide the reason for discontinuation

6. If the study is ongoing, what is the expected completion date?

For Registrant use only

7. Provide supplemental information here

Phenmedipham is moderately toxic to freshwater aquatic organisms on an acute exposure basis. The vascular aquatic plant study with phenmedipham active substance met reportability criteria for Canada due to lower endpoints as compared to the duckweed study with Lemna minor. The lower endpoints do not affect the risk assessment for phenmedipham as the level of concern was low for adverse effects to vascular aquatic plants.