The recommended age is 13+ because of anti-lead laws recently passed by a bipartisan Congress. Any product (CDs, toys, hand knitted clothing, shoes, bikes, pens) intended to be sold to children under the age of 13 as the primary target demographic needs to have every single part certified as lead free by a lab or have peer-reviewed science published that your product is not contaminated.The recommended age on the box is 13+.