Yes, they are safe-- I use mine in a variety of ways--I have different kinds as well. I have a few of the "fluid chalks" (used like ink pads) but much prefer real chalks for the effect.
I use my chalk pencils if I need finer lines to border, trace or fill in small spaces.
I use my "blocks" of chalk (5.00 for the whole set at M's)for doing back grounds and large areas.
I use my little "pie" chalks for everything else.
I LOVE to chalk. I use them with versamark ink, I use them when distressing if I want a more subtle look than inks, I use them with stamped images (also more subtle than markers or colored pencils). I have use them to enhance die-cuts, add shading to areas,with templates and stencils, around titles to set them off from the rest of the page.... The list goes on-- they are truly one of my favorite media and the best thing is they can be erased. When I am done, I usually spray a fixative on them or rub a little microglaze into them to make them stay put and not rub off. I also have chalk enhancer that makes the colors a little brighter.
Have I totally confused you??
I hope not! My recommendation is to just get some and play around! I apply them with the little poms, my fingers and for large areas I use OB tampons.
I used to use dry chalks but sold
them off after trying out Colorbox's Fluid Chalks. It's stamp pads which are much dryer than other pads and come in a endless variety of colors! Much easier to use than the dry chalks. I would recommend bying the single ones though.....