How much toluene does it take to make a room 40’X40’X8′ to achieve its LEL%?

My SDS list toluene’s lower explosive limit (LEL) as 1.2% by volume, often given as:

Calculate room volume

Room size: 40′×40′×8′

V_room = 40′ × 40′ × 8′ = 12,800 ft³

Convert to cubic meters (since gas calculations are easier in SI):
1 ft³ = 0.0283168 m3
V_room = 12,800 × 0.0283168 = 362.5 m³

Volume of toluene vapor at LEL

LEL = 1.2% by volume:
V_{toluene,vapor} = 0.012 × 362.5 = 4.35 m³

At room conditions, 1 mole of gas = 24 L = 0.024 m³ (approximate for 20–25°C):
n = 4.350.024 = 181 mol

Molar mass of toluene is 92.14 g/mol:
m = 181 × 92.14 = 16,700g = 16.7 kg

Density of liquid toluene is 0.87 kg/L:
V_liquid = 16.70.87 = 19.2 L or 5 gallons

Source: Me and Copilot