Two workers died in separate incidents after being struck by flying compressed gas cylinders In the first half of 2025. Following which another accident occurred on 28 July 2025 involving a ruptured compressed gas cylinder caused an explosion at a workplace and fortunately no one was injured .
These accidents clearly emphasize the risks and hazards associated with the use, handling and management of compressed gas cylinders and it is necessary to put in place the required risk control measures to ensure workers’ safety during the handling of compressed gas cylinders.
Workplace Accident : Worker struck by flying gas cylinder
A workplace fatality was reported on 28 March 2025, involving a worker investigating into the cause of a fire alarm triggered by a newly installed fire suppression system at a worksite. After establishing it to be a false fire alarm, the worker proceeded to remove one of the pilot cylinders containing carbon dioxide. The pilot cylinder was first disconnected from its support bracket, before it was placed free-standing on the ground. But shortly after, the cylinder suddenly flew and struck another worker standing nearby. The worker who was struck died in the hospital.
Figure 2: Position where the cylinder landed after it flew.
Workplace Accident : Worker struck by flying fire extinguisher projectile
A workplace fatality was reported on 15 May 2025, involving an excavator ( fitted with an electromagnet) being used to transfer scrap metal, a discarded fire extinguisher cylinder (containing carbon dioxide gas) suddenly flew and struck a worker seated nearby. The worker was taken to the hospital where he later died.
The cylinder’s valve connector likely broke when the excavator’s electromagnet pressed on the scrap metal pile. This would have caused the residual gas to suddenly discharge and turn the cylinder into a projectile.
Figure 3: Scene of the accident.
What companies should do
Companies should assess and ensure that their WSH management system includes the following measures or checks:
Working with compressed gas cylinders
The sudden release of high-pressure gas from a cylinder can transform it into a projectile and severely injure workers in the vicinity. Compressed gas cylinders must be properly handled, transported and stored to prevent such a scenario.
Companies carrying out similar work activities shall review their work procedures and implement the necessary control measures to protect workers working with compressed gas cylinders.
• Inspection of Gas cylinder : Implement regular checks on gas cylinders for physical damage (such as corrosion, cracks, or dents) and signs of leakage especially at its valve connector and any pipe/tube fittings used. Immediately removed any cylinder from service , valve connector or fittings found with a defect. Ensure all gas cylinders are periodically examined or tested by a competent person in accordance with the WSH (General Provisions) Regulations and the manufacturer's recommendations.
• Safe work procedures (SWPs): Establish and implement SWPs for the handling, transport and storage of compressed gas cylinders. This should be done in consultation with relevant stakeholders such as the gas cylinder manufacturer, gas cylinder transport service provider, gas system designer, plant manager, and process safety specialists.
Safe Work Procedures should consider the following content which is non-exhaustive:
Securing of the gas cylinder: Do not leave cylinders containing residual gas free-standing. Gas cylinders should be stored in an upright position and secured by chaining or fastening them to a wall bracket or other fixed supports.
Safe transportation of cylinder: Transport cylinders vertically or as upright as possible. Use a cylinder cart to move individual gas cylinders and chain or strap the cylinder to the cart securely. Never roll, slide or drag a gas cylinder as this may result in physical damage to the cylinder. Do not move a gas cylinder with its pressure regulator attached. The valve connector is also vulnerable if the cylinder falls; shut the valve connector, remove the regulator and protect the valve with a safety cap before moving the cylinder.
If the valve connector of a gas cylinder breaks off, the forces generated by the sudden gas expansion could propel the cylinder a few metres away from its original location. Therefore, it is important to use compatible valve connectors and protect the valve connector when the cylinder is not in use. It is safest to move gas cylinders when they are empty, where feasible to do so.
Use only Compatible valve connectors: Use only manufacturer-approved valve connectors that are compatible with the gas cylinder. Consult the cylinder manufacturer or supplier on the use of thread seal tape to prevent leaks at the cylinder-valve connection.
Labelling of the cylinder: Clearly label each cylinder as “FULL”, “IN USE” or “EMPTY” so that workers can easily determine its status. Train workers to verify the cylinder’s status onsite through other means e.g. by comparing the cylinder’s weight and/or pressure against the original readings when full and the expected readings when empty.
Proper cylinder storage: Store gas cylinders in a cool and well-ventilated area, and away from direct sunlight, sources of heat and corrosive substances.
• Competent workers: Deploy only supervisors and workers who are trained on the SWPs and have a good understanding of the possible hazards and risk control measures when working with compressed gas cylinders.
• Work supervision: Provide onsite supervision to ensure the SWPs are closely followed, and risk control measures are in place and effectively implemented.
For more information, refer to the WSH (General Provisions) Regulations, the Ministry of Manpower’s circular on Inspection and Filling of Compressed Gas Cylinders, SS 639: 2018 Code of Practice for the filling, inspection, testing and maintenance of gas cylinders for the storage and transport of compressed gases, and Chapter 3 of the WSH Council’s WSH Guidelines for Laboratories Handling Chemicals.
Disposal of carbon dioxide fire extinguishers
The handling and disposal of portable carbon dioxide (CO2) fire extinguishers poses a serious WSH concern as the residual pressure within an extinguisher is often strong enough to propel the cylinder and injure workers in the vicinity. All companies handling metal waste to review their risk assessments and implement the necessary control measures to protect their workers from harm.
• Responsible disposal: Work closely with upstream waste generators and service buyers to ensure only empty cylinders are received for metal recovery or recycling.
Portable fire extinguishers intended for disposal should be regarded as hazardous waste and not be disposed as general waste. They should not be sent directly to scrap metal yards unless the yard houses a facility to safely empty an extinguisher’s residual contents prior to metals handling/processing.
It is recommended to send fire extinguishers to a licensed hazardous waste disposal contractor or a specialised fire equipment disposal service provider who can handle non-empty cylinders safely.
• Safe work procedure (SWP): Establish and implement SWPs for the proper handling and disposal of incoming CO2 fire extinguisher cylinders. The SWP should cover the following (non-exhaustive):
- Separate CO2 fire extinguisher cylinders from other scrap metal waste.
- Inspect and segregate non-empty cylinders from empty cylinders.
- Temporarily store non-empty cylinders in a well-ventilated location and secure them in an upright position.
- Send non-empty cylinders to a depressurisation facility to safely release or recover residual gas.
- Verify empty/emptied cylinders are free of residual contents and mark or label them as “EMPTY” or “DISCHARGED”.
- Send only cylinders that have been verified empty to the scrap metal yard for metal recovery or recycling.
- •Competent workers: Deploy only workers who have been trained on the SWP for the proper handling and disposal of fire extinguisher cylinders. Communicate the possible onsite risks and the implemented risk controls to workers.
- Highlight the importance of detecting and weeding out non-empty cylinders that may be present in a scrap metal pile.
• Work supervision: Provide on-site supervision to ensure the SWPs are strictly followed.
• Safe work environment: Instruct the site supervisor and excavator operator to scan the work area to confirm that no workers are inside the scrap metal yard before starting excavator operations. This is because yard workers may be exposed to flying metal debris especially due to the presence of a strong electromagnet. Mark out the excavator work zone with suitable warning signs and/or erect barriers to prevent unauthorised entry while the excavator is in operation.
• Use of technology: Consider the use of technology (e.g. automated metal waste conveyor system, remotely-operated magnetic separator) to eliminate or reduce worker exposure to the risk of being struck by flying metal debris.
For more information, refer to the WSH (Risk Management) Regulations, Singapore Standard SS 578: 2019 + A1: 2022 Code of Practice for the Use and Maintenance of Portable Fire Extinguishers, the Singapore Civil Defence Force’s online page on Portable Fire Extinguishers, the National Environment Agency’s Code of Practice for Licensed General Waste Collectors, and the WSH Council’s 6 Basic WSH Rules for Safe Operation of Excavator.
Under the WSH Act, first-time corporate offenders may be sentenced to the maximum fine of $500,000 whilst individuals can either be sentenced to the maximum fine of $200,000 and/or an imprisonment not exceeding 2 years. Read more on the WSH Act penalties.
