What’s the difference between liquid hand soap and body wash (if any)?



Hands are a body part too?!?

In: Chemistry

Hands are usually dirtier so hand soap will have more soap and less “moisturizing agents” (fat).

Body wash sometimes doesn’t even have soap…

There is not much of a difference in the actual surfactants used between shampoo and body wash (surfactants are what we chemists call soaps, the act of making soap is called saponification). Hair care products will have things like glycerin, polyvinylpyrrolidone, and quaternary ammonium salts to hydrogen bond to the hair to make it feel fuller, silky, or texturized is what we say. Body wash is basically bar soap dissolved in more water. It’s marketing genius because you’re paying mostly for water. In India, laundry detergent is sold in bars to save money on shipping. We used to do the same before washing machines, then we granulized it, now we make a liquid out of it and again, marketing genius because you’re paying for mostly water; it’s usually the first ingredient in shampoo, laundry detergent and body wash. BTW, body wash and shampoo use straight short chain fatty acids to make the surfactants as they make lots of lather. Laundry detergent is something you DON’T want to suds up so they use very long chain and branched chain fatty acids for those.

I work for a well known company that makes a variety of products relating to personal care. Our hand soap and body wash are actually the same formula in our base products. In fact the base formula for these products are just distributed in different bottles and marketed as different things (Hand soap & Body Wash.)

There are differences in formula between base formula and products that have other effects like moisturizing though.

I’ve also heard, but I can not claim this as fact that our dish soap also is very similar in formula besides the scent/flavor.

Edit: For those of you wondering, retailers and vendors use the term “flavor” more commonly than scent. However they are pretty interchangeable in the industry.

Edit 2: Face wash is not the same as hand soap, there are chemicals added such as Benzoyl Peroxide or Salicylic Acid. (DONT USE HAND SOAP AS FACE WASH)

What makes a bad soap or soap that dries your skin too much?

Generally speaking body wash isn’t technically a soap, that is it is not produced via saponification like glycerin soap. Liquid hand soap is usually made with sodium hydroxide which results in highly cleansing soap. Most body wash is made by a process using potassium hydroxide which results in more lather and a more gentle product. That’s honestly the main difference. They’re very similar, however if you use hand soap as body wash you’re likely to feel a little more squeaky clean and less nice and soft.

The primary difference is their objective and consumer experience. Hand soap (assuming bar soap) is primarily soaponified fats that can be pressed into a shape. The solid form can provide some mild abrasiveness to help remove dirts. The goal is to remove as much as you can, and that’s why it generally leads to drying of the skin.

Liquid body wash will typically include less soap, more sufactant (sodium salts rather than calcium salts). It will typically include solvents like glycols which help to lather. The better body washes are careful to balance hydrophicity of the surfactants so they don’t dry your skin out too much.

For real soap rather than detergent (which is what most products marketed as soap actually are since it is cheaper/easier to produce), oils (veggie oils or tallow, butters, etc.) combine with an alkaline solution (eg. lye and a little water) which causes saponification, the process where soap is created. For solid soap, lye (aka sodium hydroxide) is needed. For liquid soap, you need potassium hydroxide.

Back in the old days when we could have guests, I frequently be complimented on the scent of my bathroom hand soap. I couldn’t tell anyone what it was because I have been filling the same bottle with different kinds of body wash for years. The scent changes all the time.

Alternatively, I’d love to know how foaming hand soap goes from liquid to foam just by a single pump.