Yes! With past refrigerants such as R-12 and R-22 you needed to be licensed to handle the refrigerant as they caused damage to the O-Zone layer and a laymen could inadvertently cause a leak of the cylinder.
R-134A, R-404A, and R-410A are HFC refrigerants which do NOT cause damage to the O-Zone layer but they do have extremely high greenhouse gas emissions. While you can still purchase them today it is important to note that as of January 1st, 2018 you WILL need to be certified to purchase HFC refrigerants such as 410A, 134a, and 404A. Click the link on the bottom of the article for the exact wording from the EPA’s website.