Maintenance work involving compressed gas systems can create significant hazards if connections fail or stored energy is released unexpectedly. During scheduled maintenance of emergency response breathing apparatus equipment, an oxygen cylinder became a projectile and injured two workers.
As part of routine maintenance of closed-circuit breathing apparatus units used by a mine emergency response team, workers identified several oxygen cylinders that required refilling. A worker connected one cylinder to a compressor using the prescribed attachment in preparation for filling.
While the oxygen cylinder was being filled, it detached from the compressor connection. The sudden release of pressurised energy propelled the cylinder from the filling station. The cylinder struck one worker on the thigh, causing bruising, before continuing across the area and striking a second worker. The impact caused multiple lacerations to the worker’s leg that required medical treatment.
The mine operator secured the area immediately after the incident, and emergency responders transported the worker with leg lacerations to hospital.
Takeaways
- Control stored energy: Recognise the hazards associated with compressed gas systems and apply appropriate controls when filling cylinders.
- Secure connections: Check that cylinders and fittings are correctly installed, tightened and inspected before starting filling operations.
- Eliminate line-of-fire exposures: Position personnel outside potential projectile paths during pressurised gas-filling activities.
- Implement engineering controls: Consider using restraints, barriers or purpose-built filling stations designed to contain cylinders if a failure occurs.
- Follow procedures: Conduct cylinder-filling activities in accordance with manufacturer instructions and site procedures.
- Train personnel: Ensure workers who handle or fill compressed gas cylinders are trained, competent and understand the associated hazards.
Summary
Compressed gas cylinders contain significant stored energy and can become dangerous projectiles if connections fail or equipment becomes unsecured. Workers must carefully plan and control maintenance and filling activities to prevent exposure to line-of-fire hazards. Thorough equipment checks, effective engineering controls and strict adherence to safe work procedures are critical to preventing serious injuries.
