Cylinders used for training purposes in buildings shall be separated by __________ if more than one container is in the same room.

When training with propane cylinders in buildings, it is crucial to adhere to safety regulations regarding the spacing between multiple containers to mitigate risks associated with leaks, fire, or explosions. The requirement of a 20-foot separation between cylinders ensures that in the event of an incident involving one cylinder, the resultant hazards are less likely to affect the others. This distance provides adequate safety for individuals present during training and helps prevent the rapid spread of any potential fires or harmful fumes.

Other distances offered as options, such as 10, 15, or 25 feet, may not align with the established safety standards. While shorter distances could increase the risk of multiple cylinders being affected during an adverse event, too great a distance could be impractical for training within limited spaces. Therefore, the 20-foot guideline strikes a balance between safety and practicality, making it the preferred choice in such training scenarios.