What safety measure should always be taken when working with gas appliances?

Ensuring good ventilation is a critical safety measure when working with gas appliances because it helps to prevent the accumulation of harmful gases, such as carbon monoxide, that may be produced during combustion. Gas appliances can emit harmful emissions, and without proper ventilation, these gases can build up in enclosed spaces, posing serious health risks to individuals nearby.

In addition to protecting health, adequate ventilation also helps to maintain the efficiency of the gas appliance. Fresh air circulation ensures that the combustion process functions correctly, minimizing the risk of incomplete combustion that can lead to both decreased appliance performance and increased emissions.

While wearing steel-toed boots, using rubber gloves, and keeping water nearby can be safety precautions in certain contexts, they do not directly address the specific dangers associated with gas appliances. For example, steel-toed boots provide foot protection, rubber gloves may protect hands from spills or cuts, and having water handy could potentially be useful for some emergencies, but none of these options ensure safety from the respiratory hazards posed by gas leaks or emissions. Thus, proper ventilation is paramount in this scenario.