What is the maximum smoke-developed index for materials exposed to airflow in plenum construction?

The maximum smoke-developed index for materials exposed to airflow in plenum construction is set at 50. This standard is crucial in ensuring safety in building design, particularly in areas where air circulation involves spaces that can contribute to smoke spread in the event of a fire.

The smoke-developed index measures the amount of smoke released by a material when it is subjected to combustion. A lower index indicates less smoke production, which is preferable in critical areas such as plenums where air distribution occurs. An index of 50 ensures that materials used in these environments do not contribute excessively to smoke generation, thus improving the overall safety and air quality in buildings.

This limit is established to help mitigate risks and enhance visibility during a fire, ultimately aiding in the evacuation process and minimizing smoke inhalation hazards.