Aryl triazolinone sub group. Inhibitor of protoporphyrinogen oxidase
5 RELATED HERBICIDES:
Affinity
Carfentrazone-ethyl 400g/kg
Blazer
Acifluorfen 224g/L
Goal
Oxyfluorfen 240g/L
Hammer
Carfentrazone-ethyl 240g/L
6 GENERAL DESCRIPTION:
A contact, fast acting, poorly translocated, non residual herbicide for the control of broad-leaved weeds in cereals, orchards and vineyards.
7 APPLICATION METHODS AND TIPS:
Good coverage is essential because this is mainly a contact herbicide.
Best results on moist soil, in fine weather on actively growing weeds with less than 8 leaves.
Use higher rate of herbicide and water on older and/or denser weed infestations.
Generally used in combination with knockdown herbicides for broader spectrum weed control.
Rainfast in 1 hour.
9 ADJUVANTS:
In most cases no adjuvant is needed.
A non ionic surfactant may improve control in some situations.
10 WATER QUALITY:
Hard water
Colloids
pH
Tank life: 10% loss over 1-2 days depending on amount of light entering tank.
11 COMPATIBILITY:
Trace elements.
14 HERBICIDE RESISTANCE:
None reported.
15 REPLANTING INTERVALS:
Crop
Time
All
0 days
16 WITHHOLDING PERIODS:
Crop
Type
Time
Cotton
Harvest
1 day
Cotton
Grazing
Don't graze or feed trash
Other crops
Harvest
Not required
Other crops
Grazing
14 days
17 RE-ENTRY PERIOD:
18 PROTECTIVE CLOTHING:
Use elbow length protective gloves, face shield or goggles when handling the concentrate.
19 SOIL:
20 MODE OF ACTION:
Uptake and translocation:
Contact. Rapidly absorbed through leaves within a few hours of application. Little translocation, very limited movement in phloem. Non residual.
Less than 0.001 ppm of carfentrazone moved to the grain when applied at 35 g a.i./ha to wheat at the late tillering stage. 0.07-0.1 ppm of carfentrazone and its metabolites were present in straw and leaves 60 days after application. Similar results were recorded in Maize.
Physiological effects:
Disrupts membranes by inhibition of protoporphyrinogen oxidase which is involved in chlorophyll production. This results in yellowing of the plant and the stopping of photosynthesis leading to death.
The herbicide requires light and oxygen for action and works better at higher temperatures.
The herbicide is modified within susceptible plants to phytotoxic compounds.
Residual Life and Breakdown:
21 SELECTIVITY:
Controls broad-leaved weeds in grass crops. It has little action on grass plants.
Crop tolerance:
Varietal sensitivities:
Effect on Clover Species:
Effect on Medic Species:
Effect on Lucerne:
Effect on Native Plants:
22 DISEASE AND INSECT EFFECTS:
23 PLANT SYMPTOMS:
Weeds
Tissue death occurs within a few hours to days of spraying. Symptoms develop more rapidly under warm, moist conditions. Under very dry conditions symptoms may be slower to develop.
Crop
No crop symptoms because it is usually applied as a directed spray or before planting. Drift may show as yellow spotting. New growth has no symptoms.
SECONDARY EFFECTS:
24 TOXICITY:
Summary:
Details:
Poison schedule: S5. Active ingredient is a non scheduled poison but it receives a S5 rating because it has more than 25% hydrocarbons as solvent in the product.
Mammalian toxicity - Low.
Acute oral LD50 - Low, >5000 mg/kg (rats), [For comparison table salt is 3000 mg/kg]
Acute dermal LD50 - Low, >5000 mg/kg (rat).
Skin - Non irritating. Non sensitising. Formulated product is mildly irritating.
Eye - Minimal irritation. Formulated product is mildly irritating.
Not mutagenic or teratogenic (i.e. does not cause cancer or reproductive problems).
Other Species -
Birds - Slightly toxic.
Fish - moderately toxic. LC50 1.6-2 ppm.
Invertebrates - slightly toxic. LC50 >9.8 ppm.
Bees - toxicity.
Algae - Highly toxic. EC50 = 15 ppb.
Metabolism:
The breakdown pathway in animals is similar to that in plants. The main breakdown is by hydrolysis, oxidation and dechlorination. Very little parent carfentrazone is left after 48 hours in plant and animal systems.
At 3 mg/kg feed daily intake for cows no residues were detected in milk, or meat. At 10 mg/kg feed daily some residues were detected in milk and kidney. At 90 mg/kg in goats residues were detected in milk, kidney and liver. There was no accumulation. The maximum transfer factor (maximum residue versus feeding rate) was 0.08% for milk and 0.13% for kidney.
About 87% of ingested carfentrazone is excreted within 24 hours with about 80% in the urine and 7% in the faeces.
Poultry fed 10 mg/kg daily intake had less than 0.007 ppm in eggs, fat and meat. 0.06 ppm was detected in liver.
In rats, 72-87% of ingested carfentrazone is passed in the urine and 10-26% passed in faeces within 7 days of consumption with most being eliminated within 24 hours. Peak plasma levels of carfentrazone and its metabolites occur at 4- 6 hours and red blood cell levels at 8-16 hours. It is rapidly absorbed and excreted.
There is little or no potential for bio accumulation.
Residues:
Wheat: At 30 g a.i./ha of carfentrazone applied post emergence to Wheat, residues were detected at 1 hour and up to 7 days after application. No residues have been detected at 14 days after application or in the grain or straw.
Barley, Oats and Triticale: At 24 g a.i./ha of carfentrazone applied post emergence to Barley, Oats or Triticale, residues were detected at 1 hour and up to 7 days after application. No residues have been detected at 14 days after application or in the grain or straw.
25 TOXICITY SYMPTOMS:
26 FIRST AID:
Contact a doctor or Poisons Information Centre on 13 11 26.
If Swallowed - Do NOT induce vomiting. Give a glass of water Contact a doctor.
If on Skin - Wash skin thoroughly with soap and water.
If in Eyes - Flush with water for 15 minutes.
If Inhaled - Remove patient from contaminated area to fresh air.
Advice to doctor - Treat symptomatically. Contains hydrocarbon solvent that may produce chemical pneumonitis. Lavage requires intubation. Activated charcoal and cathartics will assist gastrointestinal tract evacuation.
17 RE-ENTRY PERIOD:
12 hours unless impervious footwear and chemical resistant gloves are used.
27 ENVIRONMENTAL FATE:
Carfentrazone ethyl has a half life in soil of 1-5 days and its metabolites have a half life of 3-26 days in moist soil at normal temperatures. In field applications with 100 g a.i./ha applied, no detectable residues of the parent or its metabolites were found below 20 cm. In Rice paddies the half life in water of carfentrazone ethyl and its metabolites was 2-10 days and in the sediment 23-59 days. It is degraded in both aerobic and anaerobic conditions.
Aerobic soil metabolism: In a silty clay loam, it has an initial rapid breakdown over the first 8 days with a half life of 2.2-2.5 days followed by a slower breakdown rate with a half life of 43-71 days. In other soils at water contents of 50-75% of field capacity and temperatures of 10-25 degrees C the time for 50% degradation ranged from <0.1 days to 2.5 days and the time for 90% degradation varied from 0.2 days to 482 days. The acid metabolites have half lives ranging from 30-3000 days.
Anaerobic soil metabolism: Carfentrazone ethyl half life of less than 1 day and 90% degradation within 4 days.
Aerobic aquatic metabolism: Carfentrazone ethyl half life ranged from 0.84 days at 20 C to 5 days at 10 C with little difference between totally wet soils and those with surface water only.
It has a half life in water exposed to sunlight of 8.5 days.
Hydrolysis: It rapidly hydrolyses at pH 9 with a half life of 5.1 hours at 20 or 25 C. At pH 7 the half life is 13.7 days at 20 C and 8.6 days at 25 C. It is hydrolytically stable at pH 5.
Photo-degradation in water: Carfentrazone ethyl and it major metabolite rapidly photo-degrade in light. The half life is 69.7 hours at pH5 (where minimal hydrolysis occurs) This is equivalent to 8.3 days of sunlight at 40 degrees south in summer. It is stable in the dark.
It has a soil mobility that is low.
Photo-degradation in soil: Carfentrazone ethyl was not broken down by sunlight on soil.
Ground water contamination: It has a low potential for movement is soils. Under field use conditions carfentrazone ethyl and its acid metabolites remained in the top 20 cm of soil even though they have the potential to be mobile.
Bio-accumulation: Low potential for accumulation, Log P =3.36, bio-concentration factor in fish = 206.
Does not accumulate in milk and tissues.
Replanting intervals - short. No crop rotation restrictions.
31 PROPERTIES:
Colour: Yellow orange (Gardner No. 12)
Odour: Slight petroleum odour.
Water solubility at 25 C. - 42 ppm at 25 C and pH. Product emulsifies.
Oil solubility - Miscible with acetone, ethanol, ethyl acetate, methanol and methylene chloride at 23 C.
Octanol:Water ratio at 25 C. - at pH 5;
Vapour Pressure: Non volatile. 1.2 x 10-7 mm Hg at 25 C. -
Dissociation constant - pKa
Boiling point - 182 C at 2 mm Hg.
Melting point - C.
pH 5.8 at 1% solution, 5.25 at 5% solution.
Molecular weight -
Density - 1.423 g/cm3 at 25 C. Specific gravity 1.075 g/cm3 at 20 C.
Half life in water - 8.5 days at pH5 and 35 C. At 25 C, >30 days at pH 5, 8.6 days at pH 7, 0.148 days at pH 9. At 20 C, >30 days at pH 5, 13.7 days at pH 7, 0.212 days at pH 9.
Thermal stability: Stable from -17 C to 150 C.
Slightly combustible. Thermal decomposition and burning may produce toxic by products. May produce carbon monoxide, oxides of nitrogen, hydrogen chloride and hydrogen fluoride.
Flashpoint: >93 C.
Corrosive properties: Non corrosive to stainless steel and polyethylene used in sprayers.