There are DOT requirements: For example light has to be a DOT approved headlight with a clearly labeled DOT on the lens. DOT has maximum lumens emmitted in it's requirements. There is a formula to determine this as it changes from not just the light bulb or emitter itself but with the amount of reflectivity of the light housing as well.

FMVSS No.108 pertains to headlights'

Failure to meet DOT lighting requirement is illegal in most states enforceable in a few different ways.

I would bet those are not DOT approved and thus are rated as off road use only.