An asphalt collect customer arrived on site driving a hotbox vehicle, placed his order and proceeded to the dedicated hotbox loading area. He was preparing his vehicle for loading when he noticed that materials had been left in overnight from the previous shift; the burners had been left on overnight to try and keep the material in a usable state.
Whilst preparing his vehicle, the customer decided to use a release agent to try and soften the materials, making it easier for him to screw the materials out via the auger. On contact with the hot material, the release agent (suspected diesel) started to smoke heavily, and the release agent/ bitumen ignited. A fellow customer extinguished the flames with a fire extinguisher. The hotbox thermometer read 169 degrees.
KEY FINDINGS
Operator errors
- The release agent used in the vehicle preparation was believed to have been diesel, with a flashpoint of >60 degrees.
- Site procedures stipulate that diesel is prohibited for use as a release agent, this is advised in the induction process.
Operating Procedures
- The hotbox was partially loaded with materials from the previous day, the burner had been set at 160 degrees to try and keep it usable for the next day.
Site induction
- The customer had received a full site induction, however ignored the ruling of propane isolation.
Image below shows the vehicle smoking
