The chief active ingredient in most over cleaners is NaOH or sodium hydroxide, also known as lye. Other common ingredients include butane (C4H10), Monoethanolamine (HOCH2CH2NH2) and Diethylene glycol monobutyl ether (C8H18O3).
While commercial over cleaners are effective, several of the chemicals involved can be dangerous, both for the user and the environment. Lye is highly caustic and can burn eyes and skin. It can be fatal if swallowed. When using a commercial oven cleaner, the user should wear goggles, along with rubber gloves and an apron to protect clothing. Non-toxic alternatives include applying a paste made of baking soda and salt, letting it sit for five minutes, then wiping off. Users should avoid contact with the heating elements and any electrical wiring.