You should always be aware and take heed of all product warnings. Does a Prop 65 warning mean that the product will actually cause cancer or other reproductive harm when the product is used in its typical way? Not necessarily. The listing of a chemical under Prop 65 could be the result of tests on laboratory animals. Prop 65 standards for warnings are often very stringent. For example, for reproductive toxicants, the level for warnings is 1000 times lower than the lowest level at which animal studies reported no reproductive health effect. A Prop 65 warning does not automatically mean that the product is unsafe.