Things I like to avoid...
It pays to check the ingredients!
1. Sodium laurel sulphates (SLS) are an unfortunate staple in most commercial soaps. This synthetic surfactant is produced using, amongst other things, palm oil and sulphuric acid, which is derived from petroleum products. Not something most people would intentionally choose to apply to their bodies I'm pretty sure. SLS are widely acknowledged to be irritating to skin. For many people this effect only occurs when products containing SLS are left on the skin, but for people with sensitive skin it can occur even through the use of rinse-off products. Even for those who don't have particularly sensitive skin, SLS can have a drying effect on skin, which is why it is so common for people who use commercial soaps to also then use a moisturiser. Handmade soaps generally do not contain SLS, and mine certainly don't.
2. Glycerine, which is naturally produced during the soapmaking process, is chemically removed from commercial soaps, as it is more valuable to sell it as a separate ingredient which is then added to manufacture other products such as moisturisers. Glycerine is a humectant which means it attracts water, working effectively like a sponge to pull moisture to the outer skin; it also helps slow the evaporation of water off your skin. Using a real soap that has its natural glycerine intact means you are getting all the moisturising benefits (as well as the cleansing) and therefore reduces the need for a separate production process and all the packaging involved in a separate product such as moisturiser.
If glycerine is listed as an ingredient in soap, this is not referring to the natural glycerine in soap. It means that the natural glycerine has been extracted and alternative has been added - this is most commonly synthetic glycerine which is produced from petroleum, or it could be glycerine derived from sodium tallowate (animal fat), or from vegetable oil which in most cases means it has been derived from palm oil. Often glycerine is listed without further detail, so it is impossible to know the actual source of it.
3. Synthetic fragrances are commonly used in commercial soaps, and even often in handmade soaps. Anything labelled as a “fragrance” rather than an essential oil, is synthetically produced rather than naturally distilled direct from a real plant. Synthetic fragrances can be irritating to lots of different skin types, even for those who don’t otherwise have particularly sensitive skin. Of course the other main issue with them is that they are synthetic, meaning they generally require a resource-intensive production process, as compared to the distillation process for essential oils which is a much more sustainable (although also more expensive) process.