Which of the following should compressed gas containers be kept away from?

Compressed gas containers should be kept away from sources of ignition because these containers often hold flammable gases that can easily ignite if exposed to sparks, flames, or high heat. Ignition sources can lead to catastrophic events, including explosions or fires, particularly in laboratory environments where other flammable materials may be present. The prevention of ignition is critical in maintaining safety when handling compressed gases.

While it is also a prudent practice to be mindful of humidity, machinery, and sunlight, these factors are less directly connected to igniting flammable gases. Humidity can potentially affect certain chemical reactions but is not a primary cause of combustion. Complicated machinery can pose risks of accidental damage or leaks but does not inherently cause ignition. Direct sunlight might degrade certain materials but typically does not present an immediate ignition risk compared to direct flames or sparks. Therefore, ensuring that gas containers are away from sources of ignition is the most crucial safety measure.