Abstract: At approximately 4:00 p.m. on July 13, 2009, Employee #1 was assigned to unload sodium hydroxide from a tank trailer (Polar Tank Trailer, Model Number TIS 03/09, ID Number 7104, and Serial Number 1PMS322541026837) at a refinery. At the refinery, Employee #1 climbed up on top of the tank trailer to open a compressed air valve to enable unloading. Employee #1 lost his balance while standing up on top of the tank trailer and fell approximately 10 ft onto asphalt. The employer did not provide fall protection equipment to Employee #1. The tank trailer was equipped with a compressed air valve located low on the trailer so that an employee did not have to climb on top of the trailer, but this valve was not enabled at the time of the accident. Employee suffered a fractured femur and was hospitalized.