Light acoustical panels in fire rated assemblies generally: a. Compromise the fire rating by one hour.
b. Require hold down clips
c. Require pressure cleaning.
d. Are not allowed.

a. Compromise the fire rating by one hour.

Explanation:

One hour fire rating is given to materials that can resist the fire exposure. The Acoustical panels controls reverberation and they are used for echo controls. The Fire rating is the passive fire protection which can resist standard fire. The test for fire rating also consider normal functioning of the material.