I do not know if the designers considered the faulty construction methods kids usually use when building with LEGO, that these would become hazardous if the pieces were much larger. My nieces just could not make much of anything that did not fall apart. Yet, it appears that these pieces are modeled on the TECHNIC series, as they must be linked using smaller pieces resembling screws or bolts, & those are secured with what appear to be screws.
Sorry to those unfamiliar with LEGO, that paragraph may not make much sense.
But, anyway, I would assume parents are advised to supervise their kids.