Триасульфурон

Description

Triasulfuron is a sulfonylurea herbicide, a subgroup of triazinylsulfonylureas. Chemical name: 2-(2-chloroethoxy)-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide. It works selectively: it is absorbed by both leaves and roots, after which it moves throughout the plant. The target is acetohydroxyacid synthase (AHAS, also known as ALS), an enzyme for the synthesis of valine, leucine and isoleucine. Stopping the production of these amino acids stops cell division at the growth points, and the weed dies.

Basic Attributes

• CAS No: 82097-50-5 (additional CAS 135100-29-7)
• Chemical formula: C14H16ClN5O5S
• Molecular weight: 401.83
• RTECS number: DB1554000
• Developer code: CGA 131036
• Trade designations: Logran, Yantar

Physico-chemical characteristics

• Melting point: 178 °C according to ChemicalBook; 188.6 °C according to PPDB
• Density: 1.5218 (estimate); 1.47 g/ml according to PPDB
• Refractive index: 1.5630 (estimate)
• Solubility in water depends on the acidity of the medium: 32 mg/l at pH 5; 815 mg/l at pH 7; 13,500 mg/l at pH 8.4 (25 °C)
• Solubility in organic media: weak in DMSO, weak in methanol when heated
• Steam pressure: 0.0021 mPa at 20 °C
• Dissociation constant: pKa 4.34 (calculation); 4.64 at 20 °C
• LogP: 1.6 to 2.6 at 25 °C in the pH range 5–9; according to PPDB −0.59
• Storage conditions: 0–6 °C

Scope of application

• crops: wheat, barley, oats
• non-agricultural areas: pastures, roadsides, railway rights-of-way, industrial sites
• timing: pre-emergence and post-emergence application
• spectrum of weeds: dicotyledons and some cereals, including annual ryegrass, canarygrass (paradoxa grass), wild radish, lambswort, reedweed, rough poppy, rapeseed
• regulatory status: not included in the EU list under regulation 1107/2009, use in the EU ceased after September 2017 due to the risk of groundwater contamination and danger to aquatic organisms

Toxicity

• LD50 in rats: more than 5000 mg/kg orally
• LD50 in rats: more than 2000 mg/kg cutaneous
• LC50 (4 hours) in rats: more than 5185 mg/m³ inhalation

Safety Information

• GHS pictograms: GHS07, GHS09
• Signal word: "Warning"
• Hazard Statements: H332 - Harmful if inhaled; H410 - highly toxic to aquatic life with long lasting effects
• Precautions: P261, P271, P273, P304 + P340 + P312, P391, P501
• Hazard code: N - dangerous for the environment
• WGK Germany: 2
• Transport codes: UN 3077, class 9, packing group III
• Storage class: 11 - flammable solids
• Protective equipment: safety glasses, face shield, gloves

Storage and handling

The temperature regime of the warehouse is 0–6 °C, the room is dry, entry is limited, proximity to food and feed is excluded. The solubility of the substance increases sharply with alkalinity: from 32 mg/l at pH 5 to 13,500 mg/l at pH 8.4, therefore the preparation of the working solution and washing of equipment is carried out with control of the pH of the water. Wash waters and residues are not discharged into water bodies and sewers: phrase H410. Work with gloves, goggles and a face shield; in case of dust, use a respirator (H332). Storage class 11 requires removal from ignition sources.