Is tremolite in play sand dangerous?
ASBESTOS ISSUESYes, is the conclusion of our researchers Pier de Vries (geologist) and Cornelis van der Burg (chemist). And that's precisely because it was made "suitable" for play sand by grinding and sorting it. This caused the crystals interspersed with the limestone (probably calcite-dolomite) to break down to the size of asbestos needles. We can clearly see this difference in particle size compared to the other material under the microscope. The finer particles will also more easily absorb the added color. Another serious concern is that this involves unbound asbestos, meaning loose fibers. Moreover, this isn't a one-time exposure: children play with it repeatedly.
The origin of the material we examined, containing 95% calcium and 5% magnesium, appears to be a residual product from a cement quarry, no longer suitable for cement. It may have already contained primary tremolite, but in this reduced needle form, it was ground down to a hazardous asbestos. In the blue play sand, we found multiple tremolite fibers with a length-to-diameter ratio of 15:1.
Tremolite is originally a mixed mineral. If it only contains magnesium, it's pure tremolite; if it also contains iron, it's somewhere between tremolite and actinolite.
In the case of play sand, we recommend producing it from other materials that are 100% safe.
Intertoys has now withdrawn this product with number 2003178 from the market.
The photo on the left shows the blue play sand purchased at Intertoys. The photo on the right shows the asbestos-free final product after treatment in our AC Minerals process: what remains is quicklime.
