3M's Fire Barrier Water Tight Sealant 1000 NS (Non-Sag) meets UL Water Leakage Test, W Rating - Class 1 requirements for systems tested and listed in accordance with ANSI/UL 1479, provides acoustic benefits by minimizing noise transfer (STC-Rating of 56 when tested in a STC 56-rated wall assembly) and acts as a smoke seal for installations requiring the optional L-Rating. It also meets the intent of LEED® green building program credits VOC environmental regulations, meets International Building Code (IBC) and other key life safety building code requirements.