OSHA Requires training for use of Powder Actuated Tools. Here you will find links to the most common powder actuated tool license pages. Most can be complete online in a short period of time.
The training and certification process for Powder Actuated Tools is fairly straight forward covering a lot of basic things like use of PPE and safety principles, you should be able to complete in 15-20 minutes. Some sites like the Ramset site will provide you with an operator card and the ability to retrieve you card if you misplace it. While the training is basic, there is good information on proper load selection, handling of misfires, unspent loads determining if the base material you are going to fasten to is suitable for powder actuated fastening. While some of the OSHA info is somewhat vague, it is generally understood that you would want an operator card from the manufacture of the tool you are using. For instance if you are using a Ramset PAT tool, you would want to have a Ramset card and if you are using a Hilti DX-2, you would want a Hilti card etc.
Here is a link to OSHA's guidelines on the use of Powder Actuated Tools
