Our sidewalk chalk is made of calcium sulfate and other antacids. Calcium sulfate is the main component, which can reduce chalk dust, non-toxic, washable and durable. It can be easily wiped off with a damp cloth or washed off with water. It is completely safe for indoor and outdoor use. Compared with traditional chalk, our sidewalk chalk is more likely to catch dust and is healthier. Protect children and bring more happiness.