Which of the following is a significant safety concern when using LPG or CNG in confined areas?

The significant safety concern when using LPG (liquefied petroleum gas) or CNG (compressed natural gas) in confined areas is the high risk of gas accumulation. In confined spaces, any leakage of these gases can lead to a dangerous buildup because these fuels are both heavier than air (in the case of LPG) and can displace oxygen in the environment. This accumulation increases the likelihood of explosive atmospheres and poses a serious risk of fire or explosion if an ignition source is present.

Furthermore, in confined spaces, proper ventilation may be limited, which exacerbates the risk of gas not dispersing adequately. Therefore, careful measures must be taken when working with LPG and CNG in such environments to ensure that gas accumulation does not occur, including effective leakage detection systems and proper ventilation protocols to maintain safety.