Refrigerant with leak detection dye concentrate

A container of refrigerant and leak detection dye medium for supplying to an air conditioning or refrigeration system comprising:

• a storage container for storing an amount of material for subsequent supply to an air conditioning or refrigeration system, the container adapted to communicate with a hose or other connection to the air conditioning or refrigeration system for supplying the material to the air conditioning or refrigeration system;
• a refrigerant inside the storage container;
• and
• a leak detection dye medium located within the storage container, the dye medium including a dye solid adapted to fluoresce when exposed to incident radiation below about 500 nm, the dye solid having an initial state in the storage container where the dye medium is in the form of a pill, tablet, powder or an impregnated carrier substrate separate from the refrigerant, and a second state where the dye solid is dispersed or mixed with the refrigerant, after the storage container is filled with refrigerant;
• the dye solid being present in an amount such that when the dye solid is in the second dispersed or mixed state, in the refrigerant in the storage container, the refrigerant in the storage container contains the dye solid at a concentration that is suitable for leak detection in an air conditioning or refrigeration system without adversely affecting the operation of the air conditioning or refrigeration system.