Which of the following is true about identifying gas outlets to indicate the gas or vacuum provided?

• A. Name or chemical symbol
• B. Color coding
• C. Size code
• D. Piping type

Answer: (A)

The main idea is that gas outlets must be clearly labeled with the specific gas name or chemical symbol so anyone can immediately know what is supplied. This explicit labeling provides a direct, unambiguous indication of the gas or vacuum, reducing the risk of misconnection or delivering the wrong therapy. Color coding can vary between countries, facilities, and even suppliers, and colors alone may be read incorrectly or confused with another gas, so relying on a written name or symbol is more reliable and universally understood. Size codes and piping type relate more to compatibility and system design than to informing the clinician or operator which gas is available at the outlet, so they do not serve as the primary means of identification.