Agent Name

2-Methyl-4-chlorophenoxybutyric acid

Alternative Name

MCPB

CAS Number

94-81-5

Formula

C11-H13-Cl-O3

Major Category

Pesticides

Synonyms

MCPB; (4-Chloro-o-tolyloxy)butyric acid; 2,4-MCPB; 2M 4KhM; 4-((4-Chloro-o-tolyl)oxy)butyric acid; 4-(2-Methyl-4-chlorophenoxy)butyric acid; 4-(2-Methyl-4-chlorphenoxy)-buttersaeure [German]; 4-(4-Chlor-2-methylphenoxy)-buttersaeure [German]; 4-(4-Chloro-2-methylphenoxy)butanoic acid; 4-(4-Chloro-2-methylphenoxy)butyric acid; 4MCPB; Bexone; Kyselina 4-(4-chlor-2-methylfenoxy)maselna [Czech]; Legumex; MCP-butyric; PDQ; Thitrol; Trifolex; Trotox; U46 MCPB; gamma-(4-Chloro-2-methylphenoxy)butyric acid; gamma-MCPB; [ChemIDplus]

Category

Herbicides, Chlorophenoxy

Description

Colorless or white solid; Technical product is beige to brown solid; [HSDB] Cream to pale brown solid; [MSDSonline]

Sources/Uses

Used as post-emergence herbicide for weed control in green peas, spring cereals, seedling clovers, maize, and pastures; [HSDB] Registered for use on green peas and dry peas before flowering; [Reference #1]

Comments

A strong eye and mucous membrane irritant; Effects to enzymes in the liver, brain, and skeletal muscles were observed in acute rat feeding studies; Effects in high-dose sub-chronic feeding studies with dogs include small testicles, decrease in organ weight ratios and spermatogenic activity, tubular atrophy, and immature or atrophic prostate; In sub-chronic feeding studies with rats, no significant toxicological effects were observed; [HSDB] Chlorophenoxy herbicides are possibly carcinogenic to humans (Group 2B); [IARC] See "2,4-D."

Reference Link

EPA Pesticide Chemical Search

Exposure Assessment
Vapor Pressure

4.33E-7 mm Hg

Lethal Concentration

LC50 (rat) > 1,140 mg/m3

Adverse Effects
Hepatotoxin

Hepatotoxin, Secondary

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

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Processes

Industrial Processes with risk of exposure: