Warning: Sandbox Sand

While I'm not one to argue the safety of these kinds of things (I tend to err on the side of caution and would spend $450 to get "safe" sand), the reality is that most play sand is not considered dangerous, despite the "possible" presence of these particles ... the particles in sand are naturally occurring. Sand is made by crushing quartz, and these things can exist in naturally occurring quartz. It's essentially the same sand you find on a white, sandy beach.

Here's more: http://www.safbaby.com/is-crystalline-silica-and-asbestos-in-play-sand-harmful

According to the above site, most sand is considered safe. If you can find clean, coarse brown sand is best. In fact, the coarser, the better ... bigger particles are less likely to be inhaled.

HTH