The Concentrated Cleaner Myth

Cleaning products are 90% water? There might be a good reason.

Is there a better way? Kinda. Photo by Crystal de Passillé-Chabot on Unsplash

Hate disposable plastic bottles? If my Facebook ads are anything to go by, you’re not alone. You may have seen some ads online for eco-friendly cleaning products that save waste by shipping you powders or concentrates. Why pay money to ship water all the way to your home when it comes out of a tap? You can add the water at home. Just store a box of powders in your cupboard and you’re set for a year! Positive press coverage and the zero-waste movement might also convince us to try concentrated cleaning products.

My wife and I bought a starter pack from one of these companies this year. We were intrigued at the premise and wanted to give it a try. But when we looked at the ingredients, we realized: the core premise just didn’t add up.

This is because, at the end of the day, no matter how many bottles you end up with, they’ll only send you one kind of cleaning product. Why is this? It’s all because of chemistry.

How Cleaning Works

When you clean something, whether it’s a surface, an object, or yourself, you are trying to remove some soils — bad things like dirt and stains — and leave the good stuff behind (like the dyes in your clothes, or the glaze on your bathroom tiles). There are a bunch of different ways to do this, and many cleaning products use multiple techniques.

• Mechanical cleansers physically remove stuff from a surface by being hard and sharp. Brillo pads do this; so does Bon Ami (it’s made of a powdered mineral called feldspar).
• Solvents are liquids that soils dissolve in. Sometimes your soil is water soluble, in which case you’re pretty much all set, but lots of things aren’t — particularly grease. Also, sometimes water will damage what you’re trying to clean. So we can try other solvents, like alcohol, acetone, or mineral spirits.
• Bleaches work by undergoing a chemical reaction with soils that turns them invisible. This works especially well on very colorful natural substances, like red wine or blood. Those stains are still there on your clothes (sorry!), but you can’t see them anymore.
• Acids and bases, like vinegar and ammonia respectively, also undergo chemical reactions with soils. They’re particularly helpful for inorganic deposits like rust and scale, which are resistant to many other methods, though very strong acids and bases like hydrochloric acid and lye will dissolve pretty much anything (which is why you’ll find them in scary products like oven and drain cleaners).
• Finally, we come to surfactants, also known as detergents, like good old soap. Surfactants help oil and grease dissolve in water because they have a polar and a non-polar end. The non-polar ends attach to the grease while the polar ends attach to the water. Surfactants are probably the most common cleaners — besides your soap and shampoo, they’re the main active ingredients in most all-purpose cleaners, dishwasher detergents, dish soaps, and laundry detergents. This is because most of the soils that don’t dissolve in water are oily, making surfactants a great tool for getting rid of them. Most water-based cleaning products have at least some surfactants in them, or they wouldn’t be good at cleaning oil or grease at all.

Powdered Cleaners are Already a Thing

You may notice that a lot of the products above can already be bought in solid (often powdered) form! So what’s special about these new, fancy concentrated cleaners? The pitch is that they can replace the liquid cleaners you use around the house.

So maybe they send you one of each of the categories of cleaners above, right? Unfortunately, most of these cleaners either aren’t diluted with water in the first place, or are diluted for a very good reason!

Let’s go through our list.

• Mechanical cleansers: easy to find as powders already. Liquid abrasive cleansers are only about half water by weight, so the refills would be pretty big.
• Solvents like alcohol or mineral spirits are liquids, but are generally sold in pure form already. Many don’t even mix with water.
• Bleaches: the most common (sodium hypochlorite) is explosive when concentrated. (Peroxide-based bleaches are commonly sold in powdered form.)
• Acids and bases: while some, like oxalic acid and sodium bicarbonate, can be found in solid form, others are more problematic. Pure ammonia is a gas and a severe irritant, as is pure hydrogen chloride. Many have an unfortunate tendency to react with the moisture in the air and corrode whatever’s nearby if concentrated — even acetic acid (vinegar)!

This leaves surfactants, which of course can be found in solid form (like bar soap) but often are sold as pre-diluted liquids. And indeed, if you buy one of these cleaning kits, every product you get will be primarily a surfactant. For instance, all three of the household cleaners we got from Blueland — the bathroom cleaner, the glass cleaner, and the all-purpose cleaner — used sodium alkyl sulfates as their active ingredient.

What’s wrong with that, you may ask? Don’t they work? They do — but there’s a reason we have so many cleaning techniques in our toolbox. For instance, surfactants tend to leave streaks on glass. To get a streak-free shine, we want something that will evaporate, like ammonia, acetic acid, or alcohol — but if you can ship it as a powder, it definitely won’t evaporate. Or let’s say you want to remove soap scum. Soap scum is made out of surfactants! What you want is a product that will break it down chemically, like an acid. And surfactants will do nothing on inorganic soils like rust, scale, or calcium deposits. So you may want to think twice before replacing your bathroom cleaner (bleach+mechanical), glass cleaner (base+solvent), or toilet bowl cleaner (acid) — these each have powers that concentrated cleaners inherently can’t replace. Plenty of work goes into formulating good surfactant-based cleaning products, and additives like enzymes and chelating agents can help, but they still do more or less one thing.

What to Do

What are you buying at the end of the day? A decent all-purpose cleaner and some spray bottles. And all I can say is, I hope your spray bottles are better than the ones we got.

Three weeks later: the waste-saving bottle becomes what it most despised

So what should you do instead?

• First, remember that packaging waste only accounts for 3% of the GHG emissions of most consumer packaged goods, according to Unilever — and consumer products as a whole are a very small proportion of your environmental footprint. While packaging waste is very salient, reducing and decarbonizing your transportation and electricity consumption is a much better way to help the environment.
• Second, remember that there are lots of powdered and concentrated cleaning products you can buy at your local store! These include mechanical cleaners like feldspar (Bon Ami); acids like Oxalic Acid (Bar Keeper’s Friend); bases like Sodium Bicarbonate (baking soda); and, yes, even surfactants.
• Third, understand what you’re cleaning with and why. Products like vinegar, ammonia, and bleach have their uses, and you should be very thankful they’re mixed with water for your safety. And remember: you can always buy refills and reuse your spray bottles.

Disclaimer

I want to make it abundantly clear that I’m just some guy with opinions and I have no professional knowledge of cleaning products. I just use them! If you have actual knowledge, especially if you are a formulation chemist who works in this field, please get in touch — and please write your own piece, because the Internet needs more information about how cleaning products actually work, and I am the wrong person to provide it.