Q1: In PP Plastic Sdn. Bhd, propylene oxide with molecular weight of 58.08 (TLV-TWA: 2 ppm) is being splash filled into a 300 liters storage tank with the constant filling rate of 0.001 s-1. The filling is done through a manway of 12 cm diameters. The local ventilation rate is 0.5 m3/s. Estimate the concentration of the propylene oxide and the percentage of fatalities if all workers in PP Plastic Sdn. Bhd. are exposed to propylene oxide with vapour pressure of 538 mmHg for 1 hour. Suggest TWO (2) control measures to minimize the impact of propylene oxide exposure.

Q2: A 6500-litre tank containing air at 1 atm and 300K is to be inerted to 0.8 mol% oxygen concentration by using pure nitrogen. You are required to assess the following inerting techniques: Pressure purging with nitrogen at 350 kPa, followed by venting to an atmosphere. Vacuum purging to 10 kPa absolute and the vacuum releases the nitrogen until the pressure returns to atmospheric condition. Combined vacuum and pressure purge with the vacuum pressure of 10 kPa absolute and pressure purge of 350 kPa. Discuss the advantages and disadvantages of all the above inerting techniques. Recommend the best technique for practical application based on your analysis and justify your answer.