CAS No. 53780-34-0


Return to Adverse Effects

ACTIVITY: Herbicide, Plant growth regulator (anilide)

CAS Name: N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide


Adverse Effects:

Body Weight Decrease
Sciatic nerve

• Moderately persistent and mobile in terrestrial environments.

Above the USEPA's level of concern for direct acute (listed and nonlisted) and chronic toxic exposure to mammals, birds and acute (listed and nonlisted) exposure to terrestrial and semi aquatic plants.

Regulatory Information
(only comprehensive for the US)
US EPA Registered: Yes
US EPA PC Code: 114001 
(Old US EPA PC Code: 387100)
California Chemical Code 5082  
US EPA Permit Date
and Registrant:
1978, 3M 
US Tolerances: Revoked
Registered use in
(includes only a limited list of countries)

South Africa, UK, US 
Other Information
Molecular Formula: C11H13 F3 N2O3S 
Inventing Company: 3M  
Manufacturers: generic 
Other Names:

Trade Name(s):
MBR 12325

VEL 3973
S 15017
S 15733





Scientific Name(s):


Ref: USEPA/OPP Chemical Database

Of special interest:
PAN Data 
2005 - Schedule for Reregistration & Tolerance Reassessment (RED) for "Mefluidide" is expected to be December 2007. Contact at EPA: Mark Howard (703) 308-8172; According to EPA:
Through the pesticide reregistration and tolerance reassessment programs, EPA is assessing risks and making risk management decisions for older pesticides. These decisions are summarized in documents known as REDs, IREDs, and TREDs. By making decisions according to the schedule below, EPA will meet its statutory deadlines for completing reregistration and tolerance reassessment.
Some of the decision dates presented in the schedule may change due to the dynamic nature of the review process. Any pesticide decisions that are not completed during the current fiscal year will be rescheduled for the following year. EPA is committed to meeting its reregistration and tolerance reassessment deadlines.
1975 - 1993. US EPA Index of Cleared Science Reviews 
October 2001 - Glossary of Pesticide Chemicals - A listing of pesticides subject to analysis of residues in foods and feeds by the US Food and Drug Administration.  
See also
Mefluidide, potassiium salt
Mefluidide, diethanolamine salt

US Federal Register
Date Published Docket Identification Number Details

June 20, 2007


Mefluidide Risk Assessments; Notice of Availability. A risk assessment is being conducted for mefluidide, mefluidide diethanolamine salt, and mefluidide potassium salt to support the mefluidide RED. For the purposes of this assessment, all of the three active ingredients are collectively referred to as mefluidide. This notice announces the availability of EPA's risk assessments, and related documents for the pesticide mefluidide, and opens a public comment period on these documents. The public is encouraged to suggest risk management ideas or proposals to address the risks identified. EPA is developing a Reregistration Eligibility Decision (RED) for mefluidide through a modified, 4-Phase public participation process that the Agency uses to involve the public in developing pesticide reregistration decisions. This is Phase 3 of the process.

Documents in the Federal Register Docket
Reader's Guide to Mefluidide Docket # EPA-HQ-OPP-2007-0431 (June 20, 2007)

Mefluidide Use Closure Memo

• The risk assessments for mefluidide will be based on the use sites and usage date in BEAD’s LUIS report, documents presented by the registrants, and the product labels.
• The two registrants for mefluidide, PBI/Gordon (technical registrant) and The Scotts Company (end-use registrant) are supporting all of the uses for reregistration on their respective labels.
• The uses that will be included in the reregistration assessment are; agricultural/farm structures/buildings and equipment, agricultural/nonagricultural uncultivated areas/soils, airports/landing fields, commercial industrial lawns, commercial institutional/industrial premises/equipment (indoor/outdoor), golf course turf, hospitals/medical institutions premises (human veterinary), household domestic dwellings outdoor premises, industrial areas (outdoor), nonagricultural outdoor buildings/structures, nonagricultural rights-of-way/fencerows/hedgerows, ornamental and or shade trees, ornamental ground cover, ornamental herbaceous plants, ornamental lawns and turf, ornamental nonflowering plants, ornamental woody shrubs and vines, paths/patios, paved area (private roads/sidewalks), recreational areas, and residential lawns.

Table A3. Non-Food/Non-Feed Use Patterns Summary for Mefluidide (Case 2370)

TABLE A3. NON-FOOD/NON-FEED USE PATTERNS SUMMARY FOR Mefluidide, diethanolamine salt (CASE 2370)


TABLE A3. NON-FOOD/NON-FEED USE PATTERNS SUMMARY FOR Mefluidide, diethanolamine salt (CASE 2370)

Mefluidide; Diethanolamine Mefluidide, and Potassium Mefluidide- Phase 2, (30-Day Error only Correction), HED Chapter of the Re-registration Eligibility Decision Document (RED).

• There are no agricultural or any food related pesticide uses of mefluidide. Therefore, no dietary exposure from food is expected. However, there is potential for drinking water exposure due to the outdoor uses of mefluidide.
• Based on the structural similarities of mefluidide and its diethanolamine (DEA) and potassium salts, where they all share the same anion- anilide, and the physical and chemical properties of the DEA and potassium salts, where they dissociate 100% back to free mefluidide in aqueous environments, the risk assessment team concluded that mefluidide DEA and potassium salts are biologically equivalent to mefluidide and thus they share the same toxicity as the free mefluidide. Therefore, it is reasonable to bridge mefluidide toxicity data to mefluidide salts and vice versa.

• Subchronic and chronic toxicity of mefluidide is manifested by decreased body weight and body weight gain in several species tested (rats, rabbits and dogs). Dogs appeared to be most sensitive species with the critical toxicological effects of cortical nephrosis and body weight loss. In rats and rabbits, critical effects observed were tremors, hunched posture, salivation, reduced body weight and body weight gain.

• Mefluidide and its diethanolamine salt subchronic and chronic toxicity are manifested by decreased body weight and body weight gain in several species tested (rats, rabbits and dogs). Dogs are most sensitive to these effects, which occur at doses as low as 15 mg/kg/day in diets fed for one year. In addition, dogs fed with mefluidide for one year exhibited chronic cortical nephrosis at doses of 150 mg/kg/day. Increased incidence of liver hyperplastic nodules in both sexes was observed in mice fed with mefluidide at doses of 270 mg/kg/day and higher.

Mefluidide or its DEA salt has not been tested for subacute or subchronic inhalation toxicity. However, both of them are in category IV for acute inhalation toxicity.

This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These studies (listed in Appendix B) have been determined to require a review of their ethical conduct, and have received that review.

• Developmental effects of Mefluidide in rats included increased number of early resorptions and mean postimplantation loss. These effects were observed at the same dose that caused maternal toxicity indicating there was no increased susceptibility to fetuses. The maternal toxicity included tremors, decreased body weight, weight gain and mortality. In rabbit, the LOAEL/NOAEL for developmental toxicity were above the highest dose tested (60 mg/kg/day). In the 3-generation reproduction toxicity study in rats, the offspring toxicity was characterized by decreased body weights in both sexes and both litters in all generations.

• After adjusting to the pure active ingredient, the maternal NOAEL is 58 mg/kg/day and the LOAEL is 115 mg/kg/day based on clinical signs (tremors, dark material around the nose, urine stain and reddish vaginal discharge), decreased body weight gain, decreased food consumption and mortality (2/25 females). The developmental toxicity NOAEL is also 58 mg/kg/day, the LOAEL is 115 mg/kg/day based on increase in the number of early resorptions and increase in mean postimplantation loss.

• . Evidence of Neurotoxicity. Acute and subchronic neurotoxicity studies were not performed. Clinical signs of neurotoxicity (such as tremors, ataxia, atonia, decreased limb tone, salivation) were seen in several studies (14-day oral in rabbit at or above 200 mg/kg/day, demyelination study in chickens at 1000 mg/kg/day and two developmental toxicity studies in rats at 115 mg/kg/day. Edema and swelling with myelin loss in sciatic nerve was observed in a dermal toxicity study in rabbits at doses of 720 mg/kg and above. However, these effects were not seen in an additional dermal test of similar duration using a 58.2% mefluidide formulation or diethanolamine salt of mefluidide 28.8%.

Environmental Degradation. The only identified degradation product was 5-amino-2, 4-dimethyltrifluoromethanesulfonilide. It was found at a maximum daily concentration of 2.8% of applied dose (MRID 43162201, aerobic soil). The risk assessment team concluded that this degradate is not of concern based on its structure (structurally similar to the parent, there fore it is not likely to be significantly more toxic than the parent), and the fact that it is a minor degradate (<10% of the applied dose). The residue of concern for drinking water assessment is parent only.

• . The following acceptable studies are available:
- Developmental toxicity studies in rats
- Developmental toxicity studies in rabbits
- Two-generation reproduction study in rats

Mefluidide - Toxicology section for the Reregistration Eligibility Decision Document (RED) (January 31, 2007)

Mefluidide – Occupational and Residential Exposure and Risk Assessment for the Reregistration Eligibility Decision (RED)

Appendix A 1-3 Standard Formulas Used for Calculating Occupational and Residential Exposures to Mefluidide; Ocupational Handler Exposure Data and;Risk Calculations for Mefluidide; Residential Handler

Appendix B – Mefluidide Occupational Handler Risks

Appendix C – Residential Handler Risks

Appendix D – Residential Turf Post Application Risk Assessment for Melfuidide

Mefluidide Incident Report
Error Corrections First Phase for Reregistration of Mefluidide acid, Mefluidide-DEA and Mefluidide-K (June 9, 2007)
Re-registration Eligibility Document Environmental Fate and Effects Science Chapter (June 9, 2007) (162 pages)
Drinking Water Assessment for N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide (Mefluidide), N-{2,4-dimentyl-5-]]trifluoromethyl)sulfonyl]amino]phenyl’acetamide monopotassium salt (Potassium Mefluidide), and N-[2,4-dimethyl-5[[(trifluoromethyl)salfonyl]amino]phenyl]actamide Compound with 2,2’-iminobsi[ethanol] (1:1) (May 9, 2007)
Aug 4, 1997 OPP-300523 Pesticides Subject to Tolerance Reassessment.
May 15, 1996 OPP-34093 Mefluidide and Salts. US EPA's Reregistration Eligibility Decision (RED) Development Schedule.
June 7, 1995 na Mefluidide, Potassium Salt ( PBI/Gordon). Request to Delete Use of "Embark 1-L"for utility rights-of-way and roads.
Fluoride Action Network | Pesticide Project | 315-379-9200 |