Why should we recycle soap

Perhaps you might be wondering why we would want to recycle soap, since it's a fairly personal hygiene product. Well, there are significant benefits for the environment and our health, because recycled soap can be more affordable than the ones we find in our stores, so it can be even more accessible to the people that need it the most.

There are studies that say some 3 million children die every year from hygiene-related diseases that could have been easily prevented with the use of soap, while hundreds of millions of soap bars are being thrown away, instead of being recycled.

Besides this already very important aspect, we could also talk about the benefits to the environment. According to Accor, a Scandinavian chain of hotels, its guests only use 15% of the soaps, shampoos and conditioners available in the rooms and of all those that go unused, many are simply thrown away, even though they are still in their original packaging.

Despite being a personal hygiene product, soap must not find its way into the environment under any circumstances, because it's not edible by any animal. If it rests on the ground, in the ground or in the water, it can be consumed by any organism living in those ecosystems.

How soap is made. Hot process soap or cold process soap

In order to understand how easily soap can be recycled, we must go through its initial manufacturing first and here I'll focus on solid soap, since it's easier to recycle and reuse.

Soap is a product obtained through a chemical process known as saponification, a process that takes place between the molecules of an oily substance and a strong alkaline agent, such as sodium hydroxide in the case of solid soap or potassium hydroxide in the case of liquid soap.

These agents act as surfactants, meaning that they facilitate the chemical reaction between the water and the respective oils, a reaction that couldn't take place otherwise and thus, soap acts as a skin cleaning product, as we all know it.

Marseille Soap, which doesn't have anything to do with the French city, but rather refers to a production process, is one of the most common types of solid soaps out there, which is being produced using 72% vegetable oils and sodium hydroxide. This soap is being prepared in a cauldron, so through a hot saponification process, which allows it to be used immediately after it's been manufactured, though it's still recommended to let it sit for a while.

Aleppo soap is another type of solid soap also made with the help of hot saponification, using berry oil or olive oil, combined with sodium hydroxide and there are other kinds of soaps using the same manufacturing process, but there are also those made through cold saponification.

I must mention that, beyond the base ingredients, which are mostly the ones used for the production of homemade soap, large manufacturers add other ingredients, natural or chemical, to change the smell of the soap or to improve its properties.

Cold-made soap can't be made on an industrial level, since it needs to harden within two to three days before its first use.

Still, some experts in the soap manufacturing industry believe that cold saponification is better for making soap, since it has better properties for the skin, as most vegetable oils lose their properties when exposed to heat. Coconut or olive oil, for example, are some that don't suffer from this kind of degradation, since they have a better tolerance to heat.

How soap is recycled

Now that we've learned how soap is made, we can go further and learn about how it is actually being recycled.

Solid soap can be recycled in two ways, either partially or completely. Partial recycling implies eliminating the upper layers on all sides of the soap to expose the inferior layers, which haven't yet been in contact with the skin, but this way, it becomes physically smaller. The alternative, complete recycling, implies grinding the whole soap bar and heating it up so that it can be molted back into a traditional shape. However, it's recommended that we don't combine different types of soap to ensure that we maintain its original properties as much as possible.

So, if we are looking to recycle multiple types of soap with different smells or ingredients, they must be processed according to these elements in order to stay true to the original product. To ensure an optimal quality and safety for each recycled soap bar, some recyclers will resort to using special sterilizing products before manufacturing a new soap bar.

Before its first use, recycled soap is checked by scientists at special laboratories to ensure that the new product is safe for use.

One of the European companies that recycles soap and offers it to communities in need is Unisoap, a French non-profit organization based in Lyon, which was founded in 2017.

Last year we talked to the organization's founder, Pauline Grumel, to find out more about how soap is recycled and how Unisoap helps underserved communities have access to basic hygiene products.

So far, the company was able to distribute 70.000 soap bars to needing communities and recently, it started collecting other types of hygiene products, such as toothbrushes, shampoo and conditioner, also with the aim to recycle and remanufacture them.

Another lesser-known fact about soap is that it can be used as a replacement for detergents if we're looking to hand wash our clothes, because soap is gentler with the skin compared to basically any detergent out there.

How can we manufacture soap more sustainably

For the sustainable production of soap, we must take into account several things, such as the production process and the packaging we are using, if we're talking about the ones we find on shelves.

What's most important is for soap manufacturers to produce these bars as close to the original recipe as possible, so more natural and without the use of chemical agents. Afterwards comes the choice of ingredients, which must come from certified sources and the packaging itself, which should be sustainable and even from recycled components.

For those wanting to make soap at home, the situation is even simpler, because we aren't talking about packaging anymore and the ingredients that consumers have access to are less polluting than those used by companies. At the same time, we can make soap at home by using the cold saponification process, so with a lower energy consumption and the soap bar will maintain its properties better on the long run.

These are the basic things we should know about when talking about how soap is recycled, which can be made fairly easy if we are talking about solid soap, regardless of the manufacturer or the ingredients. By recycling soap, we can save valuable resources for the basic hygiene of every human and we can also protect the environment from the chemical products that must never reach the ecosystems.