2-Methyl-4-chlorophenoxyacetic acid

Agent Name
2-Methyl-4-chlorophenoxyacetic acid
Alternative Name
MCPA
CAS Number
94-74-6
Formula
C9-H9-Cl-O3
Major Category
Pesticides
2-Methyl-4-chlorophenoxyacetic acid formula graphical representation
Synonyms
MCPA; ((4-Chloro-o-tolyl)oxy)acetic acid; (4-Chloro-2-methylphenoxy)acetic acid; 2,4-MCPA; 2-Methyl-4-chlorphenoxyessigsaeure [German]; 2M-4Ch; 2M-4Kh; 4-Chloro-o-cresoxyacetic acid; 4-Chloro-o-toloxyacetic acid; 4K-2M; Acme MCPA Amine 4; Agroxon; Agroxone; Anicon M; Anicon kombi; B-Selektonon M; BH Mcpa; Banvel M; Bordermaster; Brominal M & plus; Chiptox; Chwastox 30; Chwastox Extra; Cornox-M; Dicopur-M; Emcepan; Empal; Hedapur M 52; Hedarex M; Hedonal M; Herbicide M; Hormotuho; Hornotuho; Kilsem; Krezone; Kwas 4-chloro-2-metylofenoksyoctowy [Polish]; Kyselina 4-chlor-2-methylfenoxyoctova [Czech]; Legumex DB; Leuna M; Leyspray; Linormone; M 40; MCP; Mephanac; Metaxon; Methoxone; Methylchlorophenoxyacetic acid; Netazol; Okultin M; Phenoxylene 50; Phenoxylene plus; Phenoxylene super; Raphone; Razol dock killer; Rhomenc; Rhomene; Rhonox; Seppic MMD; Shamrox; Soviet technical herbicide 2M-4C; Trasan; U 46 M-Fluid; Ustinex; Vacate; Vesakontuho MCPA; Weedar MCPA Concentrate; Weedone MCPA ester; Zelan; [ChemIDplus] UN3345
Category
Herbicides, Chlorophenoxy
Description
White solid; [Hawley] Slightly beige solid; [MSDSonline]
Sources/Uses
Used as a post-emergence herbicide for control of annual and perennial broad leaved weeds in cereals, herbage seed crops, flax, rice, vines, peas, potatoes, asparagus, grassland, turf, orchards, roadsides, forestry, and aquatic areas; [HSDB]
Comments
A skin, eye, and respiratory tract irritant; May be toxic to human reproduction or development, based on animal studies; [ICSC] May cause skin, eye, nose, and throat irritation; Effects in high dose oral studies of rats include histopathological changes to liver, kidneys, and spleen; [HSDB] Based on animal studies, not likely to cause congenital defects; No human data available; [REPROTOX] Chlorophenoxy herbicides are possibly carcinogenic to humans (Group 2B), but "No adequate data were available on the carcinogenicity of MCPA." [IARC] See "2,4D."
Biomedical References

Exposure Assessment

Vapor Pressure
5.9E-06 mm Hg
Lethal Concentration
LC50 (rat) = 1,370 mg/m3/4h
Explanatory Notes
The Guide in the Emergency Response Guidebook is for "Phenoxyacetic acid derivative pesticide, solid, toxic."

Adverse Effects

Hepatotoxin
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Diseases, Processes, and Activities Linked to This Agent

Processes

Industrial Processes with risk of exposure: