2,4-Dichlorophenoxyacetic acid

  • 2,4-D
Formula
Cl2C6H3OCH2COOH
Structure
Description
White to yellow, crystalline powder, odorless when pure, may have a slight phenolic odor due to impurities.
Uses
It is registered in the USA as a herbicide for control of broadleaf plants & as a plant-growth regulator.

Registry Numbers and Inventories.
CAS
94-75-7
EC (EINECS/ELINCS)
202-361-1
EC Index Number
607-039-00-8
EC Class
Harmful; Irritant; Sensitising; Dangerous for the Environment
R 22 37 41 43 52/53
S 24/25 26 36/37/39 46 61
RTECS
AG6825000
RTECS class
Agricultural Chemical and Pesticide; Tumorigen; Mutagen; Reproductive Effector; Human Data; Primary Irritant
UN (DOT)
2765
Merck
13,2825
Beilstein/Gmelin
1214242
Beilstein Reference
4-06-00-00908
RCRA
U240
EPA OPP
30001
Swiss Giftliste 1
G-1469
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C8H6Cl2O3
Formula mass
221.04
Melting point, °C
137 - 139
Boiling point, °C
346
Vapor pressure, mmHg
2E-5 (25 C)
Vapor density (air=1)
7.63
Saturation Concentration
526 ppm (0.05%) at 160 C (calculated)
Odor Threshold Odor threshold 3.13 mg/kg
Density
1.563 g/cm3 (20 C)
Solubility in water
Very soluble
Surface tension
66.5 g/s2 at 25 C and ph 1.4
pKa/pKb
2.98 (pKa)
Partition coefficient, pKow
2.81
Heat of fusion
13.7 kJ/mol
Heat of vaporization
62.2 kJ/mol
Heat of combustion
-3915 kJ/mol

Hazards and Protection.
Storage
Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
Handling
Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation. Use with adequate ventilation. Wash clothing before reuse.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Clean up spills immediately, using the appropriate protective equipment. Sweep up, then place into a suitable container for disposal. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable at room temperature in closed containers under normal storage and handling conditions.
Incompatibilities
Strong oxidizing agents, strong acids, strong bases.
Decomposition
Hydrogen chloride, carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
163
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Combustible material; may burn but does not ignite readily. To extinguish fire use water spray, dry chemical, carbon dioxide, or appropriate foam.
Fire potential
Nonflammable.
Hazards
Containers may explode when heated.
Combustion products
Toxic and irritating hydrogen chloride or phosgene gases may form.
Health
2
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure limit(s)
TLV: ppm; 10 mg/m3 (as TWA) (ACGIH 1993-1994). OSHA PEL: TWA 10 mg/m3 NIOSH REL: TWA 10 mg/m3 NIOSH IDLH: 100 mg/m3
Carcinogin
I-2B
Poison_Class
3
Exposure effects
May cause liver and kidney damage. Effects may be delayed.
   Ingestion
Harmful if swallowed. May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver and kidney damage. Human fatalities have been reported from acute poisoning.
   Inhalation
Causes respiratory tract irritation. May cause liver and kidney damage. Can produce delayed pulmonary edema.
   Skin
Causes skin irritation. May be harmful if absorbed through the skin.
   Eyes
Causes eye irritation. May cause chemical conjunctivitis.

First aid
 
   Ingestion
Never give anything by mouth to an unconscious person. Get medical aid. Do NOT induce vomiting. If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid. DO NOT use mouth-to-mouth respiration.
   Skin
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
UN number
2765
Response guide
Hazard class
3.2
Packing Group
III
 
USCG CHRIS Code
DCA
 
HS Code
2918 90 90