Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. Silica is most commonly found in nature as sand or quartz. Silica is the most abundant mineral in the Earths crust.

Inhaling finely divided crystalline silica dust in very small quantities (OSHA allows 0.1 mg/m3) over time can lead to silicosis, bronchitis, or cancer, as the dust becomes lodged in the lungs and continuously irritates them, reducing lung capacities. (Silica does not dissolve over time.) This effect can be an occupational hazard for people working with sandblasting equipment, products that contain powdered crystalline silica and so on. Children, asthmatics of any age, allergy sufferers, and the elderly (all of whom have reduced lung capacity) can be affected in much earlier. Amorphous silica, such as fumed silica is not associated with development of silicosis. Laws restricting silica exposure with respect to the silicosis hazard specify that the silica is both crystalline and dust-forming.

In respects other than inhalation, pure silicon dioxide is inert and harmless. Clean silicon dioxide yields no fumes and is insoluble in vivo. It is indigestible, with no nutritional value and no toxicity. When silica is ingested orally, it passes unchanged through the gastrointestinal (GI) tract, exiting in the feces, leaving no trace behind. Small pieces of silicon dioxide are also harmless as they do not obstruct the GI tract, if they are not jagged enough to scathe its lining.

Most of the sand found in Hong Kong is not specialized for kids play, but actually derived from quarried quartz rocks, this crushed rock contains crystalline silica which has been classified as carcinogen according to the EPA and OSHA. In California companies are required by law to label products that contain carcinogens. Therefore, you can find the carcinogenic label on some of the brands of play sand.

For safe play sand, it is smooth and sterilized sand which contains no free silica and no quartz, and it is made to comply with present safety standards (AP approved safe by ACMI, ASTM, EN-71). MSDS (Material Safety Data Sheets) which are widely used system for cataloging information on chemicals and including instructions for the safe use and potential hazards are also available.

It is specialized for kids play and arts works.

Play safe and have fun!!!    

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