When refrigerant trace gas becomes absolutely necessary which refrigerants should be usde to identify a leak?

When refrigerant trace gas becomes necessary to identify a leak, non-toxic options like nitrogen or helium are commonly used due to their inert properties. Alternatively, a specific trace gas mixture containing a small percentage of a detectable gas, such as nitrogen with hydrogen, can be effective. These gases are safe for the environment and easily detectable with appropriate leak detection equipment. Always follow local regulations and safety guidelines when selecting and using trace gases.