Google facebook ad policies, they have a list of things you can't promote. If you can't find what you're looking for then hit the contact button, a facebook rep will tell you if it would violate their policies. Probably better than just running a test ad which may get through and later flagged after you've started to build a business around it. If he's already marketing in the USA with FB he may have a facebook rep already, he could just ask him, otherwise start where I mentioned above.