1. A drum contains 42 gallons of mixed xylenes (o-, m- and p- ). The lid of the drum, 3 ft in diameter, is left open. Estimate:

• The evaporation rate of xylene (Q_m lb/min) Ans: 0.0245 lb/min
• The time to evaporate all of the xylene in the drum Ans: 206 hrs
• The concentration of xylene (ppm) near the drum if the local ventillation rate is 1000 ft³/min Ans: 922 ppm
• What is the TWA-TLV for xylenes? (NPG on the web)
• Is a worker in the vicinity of the drum overexposed to xylene vapors?
• If "yes", what provisions should be taken to reduce exposure?
• Suggest a simple method to eliminate or greatly reduce the hazard