New incident report
Incident Report Number: 2022-1213
Registrant Reference Number: M-782653-01-1
Registrant Name (Full Legal Name no abbreviations): Bayer CropScience Inc.
Address: Suite 200, 160 Quarry Park Boulevard SE
City: CALGARY
Prov / State: AB
Country: Canada
Postal Code: T2C 3G3
Scientific Study
PMRA Registration No. 19204 PMRA Submission No. EPA Registration No.
Product Name: Phenmedipham TC
Unknown
Unknown
Title Raphidocelis subcapitata growth inhibition test with Phenmedipham TC
Date 14-DEC-21
No
Increased health or environmental risk
The average growth rate 72 hour ErC50, LOErC, and NOErC, based on geometric mean measured values, were determined as: ErC50=16.8 ug a.s./L, LOErC=2.25 ug a.s./L, and NOErC=0.563 ug a.s./L. The average yield 72 hour EyC50, LOEyC, and NOEyC, based on geometric mean measured values, were determined as: EyC50=5.19 ug a.s./L, LOEyC=2.25 ug a.s./L, and NOEyC=0.563 ug a.s./L. The area under the growth curve for 72 hour EbC50, LOEbC, and NOEbC, based on geometric mean measured values, were determined as: EbC50=5.61 ug a.s./L, LOEbC=2.25 ug a.s./L, and NOEbC=0.563 ug a.s./L. This appears to be lower than the current acute green algae LC50 value that is considered in the risk assessment, thus would meet the criteria for adverse effects reporting [Bruns, E.; (2011) Pseudokirchneriella subcapitata Growth Inhibition Test with Phenmedipham.; MRID 49682517]
No
Phenmedipham is moderately toxic to freshwater organisms on an acute exposure basis. Therefore, it is unlikely the new green algal data would change the current aquatic risk assessment.