Hey guys, I'm looking to sell air powered rockets (like soda bottle rockets). Because it's air powered, it doesn't deal with explosives, however, I'm still worried that I may run into legal issues. So I'm looking to you guys for some questions I have

- Do I require a license to sell these rockets? I'm not selling the rocket engines, just the frame itself.
- These rockets are pretty small--less than 6 inches in height, but they are very dense, and can shoot somewhat high (say, 500 feet) I can see them being used as a weapon. Do you think there could be issues with selling them?
- Is there anything else I need to be aware of? Do I need to have them checked off by the government as 'safe'?

Thanks for your input.