Laws about Being in Possession of a Class IV Laser

Hey everyone,

So I have built my 1 Watt laser, and have seen that on laser pointer saftey that handheld class IV lasers are legal so long as they have the required safety features.

If im not mistaking, most home built lasers have no safety features, including my of course (just a simple rear toggle switch).

Is the key switch, button activation etc. only required for laser that are being sold/shipped or are they required on all Class IV lasers?

I read it under "Why U.S. laws are ineffective" here

Thanks!