Can Citric Acid Really Lift Stubborn Rust Stains From Carpet?

Nobody wants stains on their carpets, especially those nasty reddish-brown rust stains. You might've rearranged some lamps or steel furniture, only to discover an unpleasant surprise underneath — a rust stain marring your otherwise spotless carpet. 

Luckily, there is a simple stain-busting solution that homeowners swear by. Citric acid is a versatile cleaning agent and can be used alone or combined with other readily available kitchen ingredients. With just a bit of soaking and scrubbing, you'll see the rust stain on your carpet start to lift, and your carpet will be restored to its former glory.

So why does it work? It's simple chemistry. Citric acid reacts with iron oxide in the rust, breaking it down and dissolving it so it can be easily washed away. The process that happens is called chelation; citric acid creates a bond with the metal particles in rust, stopping them from sticking back to the carpet's surface.

When removing rust stains from your carpet, the first step is loosening the rust. Take a butter knife and gently scrape off rust flakes. Then, use a vacuum to suction off any loose rust particles. Once done, mix powdered citric acid with water to create a cleaning solution. The citric acid concentration in the solution you're making depends on how severe the stain is on the carpet. You can use a 5% citric acid solution for light stains, but you can go as high as 20% if you're dealing with severe rust stains. All you need to do is apply the solution directly to the stain and let it sit for a few minutes. Get a sponge or a soft-bristled brush to scrub off the stain. Rinse it off with water.

Citric acid can cause eye and skin irritation, so use gloves and eye protection and ensure that you do not inhale the mist or the powder.

If citric acid alone isn't enough to tackle a stubborn rust stain, you can whip up a more potent mixture using common kitchen ingredients. For example, you can mix equal parts of baking soda and citric acid with half a part of water to create a paste. Adjust the amount of water as needed to keep the paste from becoming too runny.

Another effective combo when it comes to removing rust from carpet is citric acid and salt. If you can't get your hands on citric acid powder, squeeze lemon juice and mix one teaspoon with about a quarter cup of salt to create a thick paste. You can also try a blend of one tablespoon of citric acid with two tablespoons of dish soap mixed into two cups of warm water.

Regardless of your combination, the process is the same: apply the mixture or paste to the stain and let it sit for a while. The longer you let it stay, the better. Scrub the stain off with a cloth, sponge, or brush, and rinse the residue with water. Lastly, don't forget to look for the source of the rust to prevent future carpet stains.