Is cleaning with baking soda better for the environment?
Cleaning with baking soda is a longtime hack associated as much with old housewives as TikTok videos. But does it really work – and is it really greener way to clean?
I don’t like cleaning. I also don’t like buying commercial cleaning products: I worry that they are harmful both to me and to the environment. As a result, you’ll sometimes find me mopping our entire kitchen floor with just kitchen roll dampened in tap water.
So when my BBC editor asked me to test a cupboard staple – baking soda – in my household chores, I agreed to give it a go. I would try a few hacks popularised online and see if they worked for me. Could they help keep my home clean, while alleviating my environmental concerns and save me money at the same time?
Keeping your home fresh by using cupboard staples like baking soda (also known as bicarbonate of soda, bicarb, sodium bicarbonate or NaHCO3, if you’re feeling chemical, but not baking powder, which is a combination of baking soda and cream of tartar) is a perennial hack, associated as much with old housewives as with TikTok videos, health sites and even the Great British Bakeoff’s Nancy Birtwhistle. The idea is that in certain situations, baking soda can replace shop-bought cleaning products, sparing not only the environment but also ourselves from harm.
You see all these concoctions with lemon juice, vinegar, baking soda and table salt. Most of these recipes are completely bogus – Dario Bressanini
I head to the grocery store and buy two small store-brand jars of the stuff for £0.59 ($0.77) a piece, along with a small jar of a branded version for £1.59 ($2.08). Then I call Nathan Kilah, a senior lecturer in chemistry at the University of Tasmania, Australia.
“Any cleaning property that we’re going to get from baking soda arises from the chemical properties it has,” he tells me. “[When we clean] there are different parts in the grime and muck that can be chemically modified by the baking soda.”
Baking soda or bicarbonate of soda is a base or alkali, he explains, meaning it has a high pH. Therefore, one of its chemical properties is that it is able to remove hydrogen in the form of an ion from other materials.
“So the molecules literally react?” I ask. “It’s not just that if I scrub something, I’m removing dirt?” Correct, he tells me. Although bicarbonate of soda is also a mild abrasive, meaning it can shift stubborn material off a dirty surface with the help of some elbow grease.
This is why using baking soda for limescale in the kettle would not be ideal – limescale is a base too, so the two wouldn’t typically react. For that, lime or vinegar work better, because they are acidic. In fact, this seems to be the golden rule. “Acids are good for cleaning up bases,” Kilah says, “whereas bases are good for cleaning up acids”. (This is why the popular online trend of combining bicarbonate of soda and vinegar into a fizzy mixture for cleaning is almost completely bogus – the two substances simply cancel each other out.)
Later, I do my first cleaning experiment. I add baking soda mixed with water onto the stained fabric of a sofa cushion and leave it for 30 minutes before wiping it off. The stain is gone – but a white ring of powder has taken its place (and will, it turns out, remain for weeks). As I wipe at the substance, it feels slippery – an indication that I am dealing with alkaline matter, according to Kilah, which you can sometimes feel even when eating cakes or biscuits made using baking soda. I also try it on stained teacups with limited success. Luckily, I have another chemist to call.
“Most of the uses I see for baking soda [for cleaning] don’t work,” says Dario Bressanini, a chemist and science communicator from University of Insubria in Como, Italy, and author of the book The Science of Cleaning. He is puzzled about the public perception of the cupboard staple. “You see all these concoctions with lemon juice, vinegar, baking soda and table salt. Most of these recipes are completely bogus,” says Bressanini.
Its high pH, he says, is baking soda’s one key power. It can be used to counteract things like bad smells in shoes, which are usually generated by organic acids produced by bacteria, and the smell of rotten tomatoes in your fridge, created by acidic liquid, but that is more or less it. And even this one power is quite weak.
I later pour a generous helping of baking soda into our bathroom sink and chase it with boiling water from the kettle. It fizzes a bit. A few bubbles form, and I feel like a wizard or a witch. But the drain remains the same. At least I didn’t clog it.
Furthermore, baking soda is not a detergent – it cannot englobe dirt. Most of the dirt around us is greasy, Bressanini says. To clean that, you need surfactants, molecules which reduce the surface tension between two materials. “Soap is a surfactant. Shampoo contains surfactant and detergents contain surfactants. Baking soda does not.”
Reluctant to give up, I tell Bressanini how I poured baking soda and hot water in a greasy oven tray the previous day, and the resulting goop was easily washed out. That, he explains, is because the fat and the soda reacted transforming into a stronger base. It is one way of cleaning a crusty and greasy pan. It turns out I produced soap – although actual soap, produced with the right ingredients in the right proportions, would have been better, he says.
