▶ TBC 48 Colors Washable Chalk is 100% Non-toxic Tested and Certified for Safe Use. Conforms to ASTM D4236 & EN71. ✎ Clean and convenient: Washable Chalk is easy to wipe, whether children in the blackboard, wall or floor painting, can be easily wiped with a towel, reduce the annoyance of parents; Chalk dust is not easy to rise, reduce the harm of dust to the human body.