When attaching an oxygen regulator to a D cylinder, what is important to remember?

The chosen answer emphasizes the critical safety aspect of using oxygen. While oxygen itself is not flammable, it does support combustion, meaning that materials that might be non-flammable in air can ignite and burn much more vigorously in an oxygen-enriched atmosphere. Therefore, it's essential to avoid using oxygen around sparks or open flames to prevent any risk of fire or explosion.

Recognizing that oxygen can enhance the intensity of a fire highlights the importance of proper handling and positioning of the oxygen equipment. Understanding this principle ensures safety protocols are prioritized when working with oxygen tanks, especially in environments where flammable materials or potential ignition sources may be present.

The other choices highlight various operational considerations, but they do not carry the same level of critical importance in terms of immediate safety. They address procedural aspects, such as positioning the cylinder or the operational uses of flowmeters, but ultimately, the key focus should always be on fire safety when handling oxygen.