Potentially Harmful? What does that even mean?
children could stumble on "potentially harmful material"
Potentially (adverb) - possibly but not yet actually.
Your stove is "potentially harmful" - you could get burned if you touch the hot parts. Your car is "potentially harmful" - you might crash or it could break down and strand you somewhere. EVERYTHING is "potentially harmful" if you look at it in the right way.
Frankly I would be FAR more worried that my child might watch flat-earth videos or become an anti-vaxer after reading garbage websites than I would be worried that they saw an assortment of genitals and orifices interacting.