NU-22B is the only R-22 replacement you need. Here???s why. The operating characteristics you know and trust. NU-22B closely mimics the operating characteristics of R-22, making it the high-performance choice for both OEM and service replacement uses. No complications, no expensive retrofits. You won???t need any product-specific tools or supplies to use NU-22B. Its compatible with all standard oils and all standard equipment components and materials used in R-22 systems. Proven quality and performance. NU-22B is in use in thousands of installations throughout the world. You can use it with complete confidence. Safe and responsible. NU-22B is nonflammable, nontoxic and is classified A1 by ASHRAE. It is also a zero ODP refrigerant.