Question 1427 Deck General

The correct answer is A) 0.15%. The reasoning is as follows: The instructions state that no one shall enter the tank if the vapor concentration is over 15% of the Lower Explosive Limit (LEL). Since the flammable limits of the liquid are 1% to 7% mixture with air, the LEL is 1%. Therefore, 15% of the LEL is 0.15%, which is the maximum allowable percentage of vapors for men to enter the tank. The other options are incorrect because: B) 0.85% is too high and exceeds the 15% of LEL limit. C) 1.05% is too high and exceeds the 15% of LEL limit. D) 7.00% is the upper flammable limit, which is well above the 15% of LEL limit.