With chemical and metal additives that are picked up by X-ray machines and metal detectors, these sealants are designed to help you comply with Hazard Analysis and Critical Control Point (HACCP) programs in food-processing facilities. Their blue color means they’re also easily spotted and removed if a piece falls into your line. They’re unpalatable to rodents, so they’re often used to seal entry points such as windows, doors, and wall panels to keep out pests.

Also known as neutral cure, these sealants are noncorrosive and won't discolor copper, brass, or concrete. They’re structural sealants, meaning they combine excellent sealing properties and high flexibility with the mechanical strength of an adhesive—they can even join dissimilar materials. Made of silicone, their resistance to UV light, moisture, and both high and low temperatures makes them suitable for both indoor and outdoor use. These sealants are room-temperature vulcanizing (RTV), so they’ll begin to cure as soon as they’re exposed to air. They’re non-sagging and won’t drip from vertical or overhead surfaces.

Elongation and joint compression/expansion tolerance indicate flexibility—the higher the values, the more joint movement a sealant can sustain.