The bulbs are specifically designed to retrofit fluorescent fixtures (T8 in particular, not T12), and specify on the box that no ballast removal is required. I have no safety concerns—especially as they’re in the garage and will only ever be on when someone is in the garage.From a comment on Amazon, if you install them in a T12 fixture, the light will shut off (thermal protection mode) when left on for some length of time. However, someone else commented they’re working fine in their T12 fixture.-rob.