What is R22 refrigerant?

R22 is a Hydrochlorofluorocarbon (HCFC) refrigerant used in air conditioners, process chillers and industrial plant cooling systems. R22 is an ozone depleting gas and EU legislation banned its stockholding and system topping up from 1st January 2016. As a result air conditioners using this refrigerant cannot be maintained and must be replaced.