I Googled it:
"Once again, they are derived from animal products, as so many art supplies are. According to Vegan Womble, markers in general contain everything from glue, watercolors, and tempera paints include gelatins, bone char, cow's milk, beeswax, honey, insect shells, and eggs." Not sure if that's for the specific type. Some of the boards and such are made from toxic materials I've read.
Check the Peta website for lists and get arounds for items.