There are various categories of corrosive substances. Among acids, some strong acids are really corrosive in nature like H2SO4, HNO3 and HCl. Some week acids like acetic acid are also included in this category. Some bases like sodium hydroxide, potassium hydroxide, ammonia and alkali metals like sodium are some other examples of corrosive material. Some dehydrating agents like calcium oxide, phosphorous pentaoxide and zinc chloride are also corrosive in nature. Strong oxidizers like hydrogen peroxide, electrophilic halogens (flourine, chlorine, bromine and iodine), alkylating agents(dimethyl sulphate) and acid anhydrides are also common examples of corrosive substances.