Although harmless, allowing the product to enter the water system should be avoided. Keratrax MS contains superior quality waxes, which are biodegradable at a very slow rate, and the product is designed to be insoluble in water after the emulsion has broken (separated) and the water has evaporated. For this reason when using Keraxtrax MS on an outdoor arena, there should be 2 days of clear weather forecast following application. Indoor arenas can be treated at any time as the water simply evaporates, just like emulsion paint.