Abstract: At 12:00 p.m. on October 12, 2021, an employee was tightening the clamp bolt/nut of a pressurized butane cylinder 6 inch head cap for a Precision Extraction Solutions, Model X10 REV2020, Serial Number 201030065047 cannabis extractor. The equipment pressure at the time was 70 psi and the employee did not depressurize the butane cylinder by closing the Dewax Valve A to stop the flow of butane into the material column. When the employee was tightening the nut, the threads of the bolt securing the clamp unexpectedly failed, causing the head cap of the cylinder to fly upwards, striking the employee in the neck and face. The employee sustained bilateral maxillary and right zygomatic bone fractures and was hospitalized for ten days for surgery and treatment.