Cola As a Rust Remover

Many cola manufacturers add small amounts of phosphoric acid to their products.

The rumors of cola's strength as a rust remover may have been greatly exaggerated. Beginning in the early 2000s, an email message made the rounds on the Internet claiming that Coca-Cola was used by state highway patrols to remove blood from car accident sites. It turns out that many cola manufacturers do use the chemical phosphoric acid to add a tart flavor to their products. Phosphoric acid acts as a rust converter and is the active ingredient in many commercially available rust removers.

Phosphoric Acid

Commercially packaged products that contain phosphoric acid may be labeled "rust removers," but the phosphoric acid in such products actually works as a rust converter. The acid converts the reddish substance we know as rust (iron oxide) into a black, crusty compound called ferric phosphate. The concentration of phosphoric acid in colas is typically very low, however. Therefore, any effect cola may have as a rust converter will be much weaker than found in full-strength rust-removal products.

Chrome, Fenders and Lawn Chairs

Motorcycle enthusiasts in the 1960s are said to have used cola to keep the chrome on their bikes at a high shine. Truckers used it to clean their grilles and fenders. Some cleaning gurus even recommend pouring it over rusty lawn furniture when it's time to spring clean. There is a verifiable history of people using cola as an inexpensive, quick cleaning aid and rust remover.

Cleaning with Cola

To clean a rusty object using cola, some cleaning experts recommend pouring the liquid over the rust or soaking the object in a container filled with the soft drink. Soaking smaller objects may be convenient. For larger or unwieldy objects, soak an old rag or some paper towels in cola and cover any rusty areas.

Scrub It Away

Once the cola has had time to do its job, there will be a dark substance where rust used to be. This is ferric phosphate. Leave the black substance in place to protect against rust forming again or use a brush or a scrubbing pad to remove it. Simply brush or scrub until the clean metal shines through.

But Is It Safe to Drink?

A study published in the journal Epidemiology found that cola beverages containing phosphoric acid were associated with increased risk of kidney stones and chronic kidney disease. The Coca-Cola Co. says that the amount of the acid in the drink is not enough to cause health problems.

References

• "Molecules at an Exhibition"; John Emsley; 1999
• Women Today: Spring Cleaning Guide
• United States Army: Rust Converters
• The Coca-Cola Co.: Myths and Rumors
• PubMed: Chronic Kidney Disease