Fifty-five-gallon drums are being filled with 2-butoxyethanol. The drums are being splash-filled at therate of 30 drums per hour. The bung opening through which the drums are being filled has an area of 8 cm2. Estimate the ambient vapor concentration if the ventilation rate is 3000 ft3/min. The vapor pressure of 2-butoxyethanol is 0.6 mm Hg under these conditions.