Science | Sep 07
Are you very picky about cleanliness? Do you wash your hands more than a few times a day? When you buy soap, are you constantly wondering which type of soap is best? Well, you’re not alone! Soap is definitely an important facet of our daily lives and all the different options available make choosing the best a little more difficult. We can, however, break hand soaps into two teams: liquid soap and bar soap. Even though bar soap has been around the longest (centuries, even!), liquid soap has become extremely popular in the last few years. So let’s examine which soap is best, taking into account how soap works, the chemical makeup of soap, the bacteria that can be found in each kind, and the impact that they have on the environment.
How well they work and the effect on skin Liquid soap backers may often state the drying effect bar soap can have on the skin. This happens because, generally, commercial hand soap tends to have a higher pH level, which can be very drying. However, there is more than one type of bar soap available, many with lower pH factors! As a matter of fact, most bar soaps do contain glycerin which is very therapeutic for dry skin and other sensitivities like eczema, and those with lower pH levels have absolutely no drying effects on skin.
Ingredients Bar soap is most commonly made from saponified animal fat and/or plant oils (like ours!). For those of us that don’t understand chemistry, saponification is the name of the process by which animal or vegetable fats are blended with a strong alkali to make soap. On the other hand, liquid soaps are petroleum based and require emulsifying agents and stabilizers in order maintain their consistency. These agents have been tested and approved by the appropriate governing agencies but few if any actual studies exist showing the long-term effects of repeated use of these chemicals.
Bacteria We have explained this more in depth before. Liquid soap has been promoted as being anti-bacterial almost from the beginning of its introduction into the marketplace. A study in the early 90s by the Dial Corporation studied wether or not bacteria from a used bar of soap transferred to the skin. Short answer: no, it doesn’t. So in this regard, both hand bar soaps and liquid hand soaps are equally safe when dealing with bacteria.
Ecological considerations and waste More than 40% of shoppers buying skin care products consider themselves “ecologists” or, at least, having concern for environmental factors. However, most don’t know that a 2009 study done at the Institute of Environmental Engineering concluded that liquid soaps leave a 25% larger carbon footprint than do bar soaps. Yeesh! Because of the chemical formula of soap and its ingredients, it takes more chemical feedstocks and processing to manufacturing liquid soap. In fact, it takes about 7 times more than when manufacturing hand bar soap. That means 7 times more energy use and carbon emissions!
Fragrance-free options It’s not a secret that some people have allergies and adverse skin reactions to harsh fragrances. Other people just prefer to not have them on their soap. In this sense, bar soaps win. Liquid soaps that are fragrance-free are rare and can be difficult to find. On the other hand, a lot of different fragrance-free bar soaps exist, as well as bar soaps made with completely natural ingredients and with very gentle fragrances.
Conclusion (Tl;dr) Which kind is better? Well, it depends entirely on the factors that are most important to you. If ecology and going green are important to you, then bar soap wins hands down. If the decision is financial, bar soap wins again by a significant margin (washing your hands with bar soap is about a third of the cost as using liquid hand soap). If moisturizing effects and a strictly rich lather are on the top of your priority list, then liquid soaps are the way to go. However, from a purely health-conscious standpoint, bar soaps contain fewer chemicals and do just as good a job in preventing the spread of germs as their liquid counterparts. Want to try a great hand bar soap that is both green and an effective moisturizer? We know just the one!