What is the maximum length for a supplied airline from the source?

• A. 100 feet
• B. 200 feet
• C. 300 feet
• D. 500 feet

Answer: (C)

The main idea is that there’s a limit to how far a supplied-air line can safely carry breathing air to a wearer. As the line gets longer, friction and pressure losses increase, which can reduce the flow and pressure at the far end where the respirator is. To ensure the user always gets enough air, standards set a practical maximum length for the supplied airline. For typical supplied-air systems used in hazmat operations, that maximum length from the air source is 300 feet. This length keeps the air pressure and flow within reliable ranges even when the user is inhaling harder or the line has bends or minor imperfections. Shorter lengths like 100 or 200 feet would work, but they limit distance unnecessarily; a longer line like 500 feet would risk insufficient air delivery. Remember that the exact limit can vary with hose size and equipment, but 300 feet is the common maximum.