The time weighted average concentration(TWA) of benzene in workplace (42 29 mg/m 3) was higher than that of our national maximum allowable concentration (6 mg/m 3).

• 作业车间空气中苯的时间加权浓度 (TWA)为 4 2 2 9mg m3,高于国家卫生标准 (6mg m3)。