Final answer:
The most significant safety hazard with CNG cylinders is the potential for explosion. If there is a fire or the cylinder heats up, the pressure inside the cylinder can rise, and if it exceeds the cylinder's safety limit, it could lead to an explosion.
Step-by-step explanation:
The most significant safety hazard with CNG cylinders is the potential for explosion.
CNG stands for compressed natural gas, which is stored in cylinders at high pressure (around 200 atmospheres) to increase its energy density. If there is a fire or the cylinder heats up, the pressure inside the cylinder can rise, and if it exceeds the cylinder's safety limit, it could lead to an explosion.
Examples of similar reactions include unventilated or improperly adjusted gas heaters or appliances, which can release carbon monoxide (CO), a colorless and odorless gas that can be harmful when inhaled in large amounts.