Ultra Binder contains clay and charcoal as active ingredients, which are known to contain naturally occurring chemicals that can be dangerous in high amounts. Because of Prop 65, we are required by law to make our customers aware of the presence of potentially harmful elements in this product. While we use the purest ingredients available, lead is everywhere in the environment and is found in the soil where plants are grown, therefore it is impossible to avoid in many plant-based ingredients. See Prop 65 Document for more info.