MCPB, 2,4-MCPB, 4-(4-chloro-o-tolyloxy)butyric acid (IUPAC), or 4-(4-chloro-2-methylphenoxy)butanoic acid (CAS) is a phenoxybutyric herbicide. In the United States it is registered for use on pea crops before flowering, for post-emergence control of broadleaf annual and perennial weeds including Canadian thistle, buttercup, mustard, purslane, ragweed, common lambsquarters, pigweed, smartweed, sowthistle, and morning glory. It has low to moderate acute toxicity, with kidney and liver effects as the main hazard concerns. It is not volatile, persistent, or likely to bioconcentrate. The maximum residue permitted on peas is 0.1 parts per million.

CAS：94-81-5
中文别名：4-(4-氯-2-甲基苯氧基)丁酸;二钾四氯丁酸;2-甲-4-氯丁酸;
英文别名：4-(4-chloro-o-tolyloxy)butyric acid;Thitrol;Butanoic acid, 4-(4-chloro-2-methylphenoxy)-;4-(4-chloro-2-methylphenoxy)butanoic acid;Bexone;2M-4CM;Legumex;Trifolex;MCPB;Trotox;MCP-butyric;
分子式：C11H13ClO3
分子量：228.672
精确质量：228.055
Psa：46.53
Logp：2.892

MDL号：MFCD00002820

密度：1.23g/cm3
沸点：393.1ºC at 760mmHg
熔点：99-100ºC
闪点：191.5ºC
折射率：1.536
储存条件：库房通风低温干燥,与食品原料分开储运

RTECS号：ES8575000
安全说明：S26; S36; S37
WGK Germany：3
危险类别码：R50/53
危险品运输编码：UN3077 9/PG 3
海关编码：2918990023
危险品标志：Xi

生产方法
本品由2-甲基-4-氯苯酚与γ-丁内酯反应生成。 用作农用除草剂。
用途
用作农用除草剂。