Perm-A-BarrierĀ® S100 Sealant is a one part neutral curing, ultra low modulus silicone sealant that reacts with atmospheric moisture to form a durable and flexible building sealant. S100 sealant is designed for a variety of uses with GCP Applied Technologies' air and weather barrier systems. The Volatile Organic Compound (VOC) content is <100 g/L.