If lead based paint is covered with non lead based paint is that sill hazardous?

Lead based paint is hazardous when it's sanded because dust containing lead gets into the air and you end up breathing it. It can also be hazardous if someone eats it, as small children and dogs might do if they chew on a windowsill or doorframe. The paint is not hazardous just sitting there on the wall or whatever, it has to be consumed in some way to be dangerous. The only hazard I can see is that if you cover the lead-based paint with other paint, the next person might sand through the other paint and the lead paint and not realize that the bottom layer contains lead.