Cool Seal™ A/C Leak Sealer seals refrigerant leaks in compressors, condensers, evaporators, O-rings, and hoses. Cool Seal seals leaks as large as 0.02 inch (0.5 mm) and can remain safely in the system to guard against future leaks. It’s an economical alternative to expensive parts replacements on older air conditioning and refrigeration systems. Cool Seal meets ASHRAE 97 standards for chemical stability. Its non-polymer, oil-soluble formula is safe for most air conditioning and refrigeration system components and recovery equipment. It works in most popular air conditioning and refrigerant systems, including high-pressure R-410A systems. Cool Seal is nonflammable, has no storage-related safety issues, doesn’t require system pump down, and allows technicians to see the contents injected into the system.