2,4-Dichlorophenoxyacetic Acid
- CAS
- 94-75-7
- EC
- 202-361-1
- Sectors
- Agriculture
2,4-Dichlorophenoxyacetic Acid (CAS 94-75-7) is a chlorinated phenoxyacetic acid herbicide and synthetic auxin, supplied as a white to yellow crystalline powder that acts systemically on broadleaf weeds, and is used for post-emergence weed control in cereals, maize, sorghum, grasslands, turf, forestry and aquatic systems. It has a density of 1.42 g/cm³, melting point 138°C, boiling point 160°C at 0.4 mmHg; slightly soluble in water (0.9 g/L), soluble in organics; systemic herbicide, synthetic auxin. Produced by chlorination of phenoxyacetic acid, it mimics plant growth hormones causing uncontrolled growth in broadleaf weeds.
Typical Properties
| Molecular formula | C8H6Cl2O3 |
|---|---|
| Molecular weight | 221.04 g/mol |
| Form | crystalline |
| Color | off-white to tan |
| Melting point | 138 °C |
| Boiling point | 160 °C @ Press: 0.4 Torr |
| Density | 1.42 g/cm³ @ Temp: 25 °C |
| Water solubility | Slightly soluble. Decomposes. 0.0890 g/100 mL |
| Flash point | 160°C/0.4mm |
| GHS signal word | Danger · Corrosive, Irritant / harmful, Health hazard, Environmental hazard |
| HS code | 29189090 |
Typical literature values for identification; lot-specific results are stated on the certificate of analysis (COA) and the safety data sheet (SDS) that accompany every delivery.
2,4-Dichlorophenoxyacetic Acid
Applications
Used as selective herbicide for post-emergence weed control in cereals, maize, sorghum, grasslands, turf, and aquatic systems; in forestry for brush control; in research for auxin studies; formulated as salts/esters for better solubility; in lawn care for broadleaf weeds.
Safety & Risks
Irritant to eyes/skin/respiratory (H315, H318, H335); possible endocrine disruptor and carcinogen (IARC Group 2B). Harmful if swallowed (H302); avoid dust inhalation. Stable but decomposes at high heat; incompatible with strong bases/oxidizers. Use PPE, ventilate; monitor exposure.
Packaging
Typically in 25kg multi-wall paper bags with PE liners or fiber drums; store in cool, dry, ventilated areas away from food.