The Department of Environment and Natural Resources (DENR) wishes to advise the public that most air conditioning refrigerants released into the air contribute to climate change or depletion of the ozone layer. In an effort to avoid this, all domestic and commercial HVAC system technicians who handle or manage refrigerant gases must have undergone the necessary training and have a valid “Certified Technician” photo ID Card issued by the Department of Environment and Natural Resources. This helps to ensure the proper reclamation, reuse or disposal of refrigerants.