Famoxadone

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Chemical Identification | General Product Information | Physical & Safety Data

Chemical Identification

Common Name

Famoxadone

中文通用名

噁唑菌酮

IUPAC

(RS)-3-anilino-5-methyl-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione

CAS

5-methyl-5-(4-phenoxyphenyl)-3-(phenylamino)-2,4-oxazolidinedione

CAS No.

131807-57-3

Molecular Formula

C₂₂H₁₈N₂O₄

Molecular Structure

General Product Information

Category

Fungicides > Oxazole fungicides
Fungicides > Dicarboximide fungicides

Activity

Famoxadone provides activity against a broad range of plant pathogens. It has protectant, translaminar and residual properties. In trials, famoxadone did not lose activity following simulated rainfall and its activity is termed ‘intracuticular’ by DuPont. The product was safe to target crops at twice the recommended use rate. DuPont recommends its use with established fungicides for season-long control.

The biochemical mode of action of famoxadone is inhibition of the mitochondrial respiratory chain at complex III resulting in decreased production of cellular ATP. In studies with Phytophthora infestans, application of famoxadone to the zoospores of this organism caused the cessation of oxygen consumption and motility within seconds, followed by the disintegration of the cells.

This product has been included in the new anti-resistance guidelines issued by the Strobilurin Type Action and Resistance (STAR) Working Group. The group has suggested that growers limit the number of applications to a maximum of four within a total fungicide spraying programme. DuPont points out that famoxadone is not a strobilurin and has no chemical relationship with these fungicides. Studies carried out by the company revealed that the risk of resistance to famoxadone-based mixtures is “very low”. However, famoxadone is generally classified as belonging to the ‘QoI’ group along with fenamidone and the strobilurins. Erysiphe graminis tritici and Sphaerotheca fuliginea have developed a resistance to this group due to a point mutation (G₁₄₃A) in the cytochrome b gene, and were found to be as fit as sensitive wild-type under growth room environment conditions (BCPC, 2000). However, resistant populations of Plasmopora viticola (carrying the G₁₄₃A mutation) were found to be less fit than the sensitive wild-type.

In Europe, famoxadone may be applied up to 12 times per season to grapes and up to 8 times per season on tomatoes.

CropUse

CropUses:
barley, cucurbits, lettuces, oilseed rape, peas, peppers, potatoes, sugarbeets, tomatoes, vines, wheat

Cereals	maximum dose, 280 g ai/ha
Vines, tomatoes	maximum dose, 90 g ai/ha

Premix

Mancozeb+famoxadone
Flusilazole+famoxadone
Famoxadone+Pyraclostrobin
Famoxadone+Oxathiapiprolin
Famoxadone+Fluazinam
Famoxadone+Dimethomorph
Famoxadone+Cyazofamid
Famoxadone+Azoxystrobin
Cymoxanil+famoxadone
Premix Parters:
cymoxanil; fosetyl-aluminum; mancozeb; propamocarb hydrochloride;

Physical & Safety Data

Physical Properties

Molecular weight:374.4; Melting point:140.3-141.8 °C; Vapour pressure:6.4 × 10-4 mPa; Henry constant:4.61 × 10-3 Pa m3 mol-1 ( calc., 20 °C); Partition coefficient(n-octanol and water):logP = 4.65 ( pH 7); Solubility:In water 52 ppb (20 °C).;

Toxicology

Oral:Acute oral LD₅₀ for rats >5000 mg/ kg. Percutaneous:Acute percutaneous LD₅₀ for rats >2000 mg/kg. Not a skin or eye irritant (rabbits). ADI:0.025 mg/ kg.

Environmental Profile

Ecotoxicology:
Bobwhite quail [8 d] LC50 >5,620 mg/kg ；Honeybee [oral] LD50 >63 μg/bee ；Mallard duck [8 d] LC50 >5,620 mg/kg；Honeybee [contact] LD50 >25 μg/bee；Rainbow trout [90 d] NOEC = 0.0014 mg/L；Daphnia[48 h] EC50 0.012 mg/L；Green algae [72 h] EbC50 = 0.022 mg/L；Earthworm LC50 = 470 mg/kg soil

Environmental fate:
Fate in :
Based on data submitted, famoxadone is acutely toxic to both fish and daphnia. Consequently, the EU SCP recommended the implementation of buffer zones to avoid toxicity to aquatic organisms.

Fate in soil:
In laboratory studies carried out using various aerobic soil types at 20°C, the DT₅₀ was found to vary between 2 and 11 days, and the DT₉₀ between 56 and 248 days. In three soils, the major metabolites IN-KZ007 and IN-JS940 were found to have a DT₅₀ of 1.5 to 10.3 days (mean 5.0 days), and 6 to 23 hours (mean 16 hours), respectively, at 20°C. In anaerobic soil at 20°C, the DT₅₀ was 28 days whilst the DT₉₀ was 91 days. Data from field studies was not required.
The K_d/K_oc ratio in three soil types varied from 3300 to 4030 indicating that famoxadone is not very mobile. Column leaching studies were not required. In aged residue leaching studies, <0.1% of radioactivity was found in the leachate. The radioactivity was only detected in the top 0 - 5 cm of soil. Lysimeter/field leaching studies were not required.
Famoxadone has a photolytic half-life of 4.1 days.

Fate in aquatic systems:
The rate of hydrolytic degradation at 20°C is pH-dependent with DT₅₀ of 41 days at pH 5, 2 days at pH 7 and 1.5 hours at pH 9. Famoxadone is degraded photolytically with a half-life of 1.9 days in continuous light at pH 5.
In water/sediment study, the DT₅₀ and DT₉₀ in water are 0.07 - 0.43 hours and 1.6 - 23 hours, respectively, whilst the DT₅₀ and DT₉₀ for the whole system are 0.68 - 0.8 days and 14 - 15 days, respectively.