Should You Swap to Soap Bars to Reduce Your Environmental Impact?

Liquid soap vs bar soap: which is the more environmentally friendly option?

Tabitha Whiting
5 min readJun 15, 2019
Photo by Kelly Sikkema on Unsplash

Solid soap bars are staging a come back. Until recently, I generally only associated soap bars with my grandma’s bathroom, and hotel room freebies. But now it seems like soap bars are cool again, thanks to the plastic-free movement. Soap bars use much less packaging to store, and less water to produce. Plus, they tend to last a lot longer. So should you swap from liquid soap to solid soap bars to reduce your environmental impact?

What’s the difference?

Photo by Nefeli Kavvada on Unsplash

There is a chemical, as well as aesthetic, difference between liquid soap and soap bars. Soap is made from a combination of fat/oil, water, and an alkali (traditionally lye). Liquid soap, on the other hand, is usually a synthetic detergent, made from chemical compounds rather than fats and oils.

There is, therefore, much debate about whether we should be using so much chemical-filled liquid soap at all. This is especially true with antibacterial liquid soap. You may have noticed that the adverts advertising hand wash which ‘kills up to 99.9% of bacteria’ have slowly disappeared in the last couple of years. That’s because scientists started speaking out about these antibacterial soaps, and how they’re contributing to antibiotic resistant bacteria. There has also been no research which has found that antibacterial soap is more effective at cleaning than ordinary soap.

Liquid soap is a common sight today, but it only became an option fairly recently. It was first patented in 1865 by William Shepphard, but for the following century was used almost exclusively for industrial purposes. It wasn’t until the 1980s when it was first mass-produced, and became used domestically. To convince homeowners to buy liquid soap instead of soap bars, it had to be easy to use. And so, the pump dispenser was born.

Solid soap bars, made from fats and oils, have been around for much much longer. Evidence has been found of a soap-like substance as far back as 2800 BC. We also know that the ancient civilisations of Babylonians, Mesopotamians, Egyptians, ancient Greeks and Romans all made soap, by combining fats and oils with salt and water.

Is one more eco-friendly than the other?

Photo by Heather Ford on Unsplash

When you start evaluating your consumer decisions in terms of how environmentally friendly they are, it soon gets pretty frustrating. Generally speaking there’s rarely a right answer. So much depends on the specific product you’re purchasing: where it was made, how it was transported, how it was packaged, and so it’s never as straightforward as you think. When it comes to soap, though, it seems like the situation is more black and white.

Let’s start with packaging. Swapping to solid soap bars is often on lists of things you should do to reduce your plastic waste, and for good reason. You can usually buy soap bars loose or in recyclable cardboard packets (just avoid Dove soap bars, which are plastic wrapped inside their cardboard box). Liquid soap, on the other hand, will always come in a plastic bottle.

Those plastic bottles of liquid soap are also much heavier than a soap bar, due to the increased water content. That means they’re also more difficult to move around, and use more energy in transportation. It also takes more energy to produce in the first place — using up to five times more energy to produce liquid soap than a solid soap bar.

The story continues once you’ve actually got the soap into your own bathroom. Studies have shown that we use liquid soap much more quickly than solid soap bars. That might be because we feel like more soap equals more cleaning power, or it could be because manufacturers develop overly generous pump dispensers to make us buy more regularly. Either way, on average we use seven times more liquid soap than solid soap. Researchers have also shown that we use more water when washing our hands with liquid soap, than solid soap bars — around 30% more.

So should you swap to solid soap to reduce your environmental impact? It seems like the answer is a pretty resounding yes. It’s a super simple swap that most of us could make immediately, without inconveniencing us much.

However, if we calculated the greenhouse gas emissions you actually saved each year by using soap bars instead of liquid soap, it would be a pretty minor saving. That’s because there are a few much bigger factors which dominate our individual carbon footprints: the transport methods we use regularly, how we eat, and the energy we use to power our houses. So, if you’re serious about wanting to reduce your environmental impact, start with these factors. If you’re cycling and walking when possible, reducing the amount of meat and dairy in your diet, and using a renewable energy provider, then you’re already doing a great job at reducing your environmental impact. And f you want to opt for solid soap bars to go the extra step, then by all means do.

If you liked this post, you might also like my posts on other common decisions which influence your nvironmental impact:



Tabitha Whiting

Exploring the good and the bad of climate change communication and sustainability marketing 🌱