Abstract: A flammability test apparatus comprises a chamber, an inlet, an ignition source, a heater, and pressure and temperature sensors. In one embodiment, the chamber includes a horizontally-oriented, cylindrically-shaped section. The inlet allows a fluid to be introduced into the chamber. The ignition source ignites the fluid within the chamber, and the heater adjusts the temperature of the fluid within the chamber. The test apparatus includes a sparger for dispersing the fluid within the chamber, and the sparger disposed within the chamber and attached to the inlet. The test apparatus also includes a relief system for exhausting the chamber after the pressure of the fluid in the chamber exceeds a preset pressure.