“What kind of sand should an artist use for sand animation?”
Artists often use toxic materials without even realizing it. There are no institutions actively protecting artists from hazardous substances. Therefore, it is very important to be aware of the hidden dangers of your art materials.
Artists are responsible for self-education when using materials that are new to them. Everyone must take personal responsibility in dealing with the dangers of their desired materials. Often, the things that work the best are the most dangerous. Vincent Van Gogh was known to have put his paint brushes in his mouth, causing himself to suffer from chronic lead poisoning. This likely contributed to his delusions and hallucinations.
Here’s a WARNING for potential sand artists:
Please be aware of the possible dangers of sand... Don't just go to the beach and pick up a bucket of sand to start practicing. Make sure that the sand you use for sand animation does not contain "free-silica". This is a dangerous dust that can cause Silicosis, which is a form of lung disease caused by inhalation of crystalline silica dust. If your sand “sticks” to you, and creates a lot of dust, or makes you cough, it probably contains free-silica.
The recognition of respiratory problems from breathing in dust dates as far back as ancient Greece and Rome. Free crystalline silica is one of the most common minerals in the earth's crust. It is found in sand and many rocks. But, don't worry, you can easily get free-silica free sand from many reputable sand dealers.
Look for sand that is free-silica free and safe for kids!
Use common sense and do adequate research before using any art materials that are new to you.
Be safe… enjoy your art, and enjoy life!