text: It is produced with high efficiency by reducing sodium chlorate in a strong acid solution with a suitable reducing agent such as methanol , hydrogen peroxide , hydrochloric acid or sulfur dioxide .
simplified: There are some reducing agents ( chemicals that reduce another chemical ) that can be used . Methanol ( an alcohol ) , sulfur dioxide ( a gas made by burning sulfur ) , hydrochloric acid ( a common acid ) , or hydrogen peroxide can be used .