FDA / GMP guidelines

If I understand the question correctly, you are looking for an answer to whether the FDA / GMP guidelines say when to produce in a clean room. It is not up to the guidelines to tell you whether or not to produce your medical device in a clean room. That is the decision of the Top Management. The guidelines are there to show you how clean rooms need to be installed, how to maintain them, what to measure, how to validate them, and the like. Most often, medical devices that must be sterile are produced in clean rooms.