Which value would violate the plenum duct liner smoke index limit (maximum 50)?

Which value would violate the plenum duct liner smoke index limit (maximum 50)?

• A. 50
• B. 60
• C. 40
• D. 0

Answer: (B)

Smoke index shows how much smoke a material releases when heated, and plenums require it to stay under a set limit to keep smoke production low during a fire. The limit here is 50, so anything higher would violate the requirement. That means the value exceeding the limit is not allowed, while a value at the limit or below meets the rule. In this set, the value above the limit would violate (for example, 60), whereas 50 sits at the limit and is compliant, and 40 and 0 are below the limit and also compliant. Lower smoke production helps maintain visibility and safer evacuation during a fire.

Smoke index shows how much smoke a material releases when heated, and plenums require it to stay under a set limit to keep smoke production low during a fire. The limit here is 50, so anything higher would violate the requirement. That means the value exceeding the limit is not allowed, while a value at the limit or below meets the rule. In this set, the value above the limit would violate (for example, 60), whereas 50 sits at the limit and is compliant, and 40 and 0 are below the limit and also compliant. Lower smoke production helps maintain visibility and safer evacuation during a fire.