At any given time, your hands play host to millions of germs -- bacteria and viruses that can make you ill if you ingest them. Washing your hands with plain water may flush away some of these germs, but many remain clinging to the skin. Only by washing with soap, a surfactant that bonds with soil and strips it free of the skin, can you eliminate 90% or more of the germs from your hands. So, how much soap do you need to wash your hands effectively, and do soap dispensers provide enough with each pump? We've done the research, and we have the answers for you!
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The amount of soap dispensed in a single pump varies depending on the type of dispenser. Disposable liquid soap dispensers typically eject about 2 mL per pump, while disposable foaming soap dispensers eject approximately 1.5 mL. Refillable pump (or manual) dispensers for both liquid and foaming soap dispense an average of 1 mL per pump. Most automatic dispensers are programmed to release 0.7 or 0.9 mL; however, many of those intended for use in homes have adjustable dispensing systems that allow them to be set anywhere from 0.1 to 4.5 mL.
In the remainder of this article, we'll discuss each of these types of dispensers and why it is designed to emit a specific volume of soap. We'll also explore the recommended amount of soap to use for handwashing, the differences between liquid and foaming soap, and how many handwashings you can expect to get from both liquid soap and bar soap. Keep reading to learn more!
How Much Soap Does A Soap Dispenser Dispense?
Manual Pump Liquid Soap Dispensers
Manual dispensers of liquid soap consist of a bottle topped by a pump made of plastic or metal, with a thin piece of plastic tubing attached to the pump and extending down into the liquid soap. When the user depresses the pump, the soap within the plastic tube is ejected onto the user's hand. Releasing the pump creates a vacuum that allows the tube to refill with soap. Some manual dispensers of liquid soap are disposable; others are designed to be refilled and used for years.
Disposable Manual Soap Dispenser
A typical, disposable manual dispenser ejects about 2 mL of liquid soap per pump, more than any other dispenser type. This may not be surprising because the manufacturer has an incentive to design them this way: the sooner the receptacle empties, the sooner the user has to buy another dispenser. However, many users get around this issue by simply taking less than a full pump for each handwashing. In fact, the average user takes about 1.5 mL per handwashing.
Refillable Manual Soap Dispenser
Refillable manual soap dispensers are made of metal, plastic, glass, ceramic, or resin; they come in a wide variety of styles and colors to match the decor in any bathroom. Refillable dispensers have two major advantages over disposable ones: first, they greatly reduce the amount of plastic waste generated, and second, they last for years saving the user money in the long-term. Although there is some variation in the volume of liquid soap dispensed by different models, most refillable manual dispensers eject 1 mL per pump.
Manual Pump Foaming Soap Dispensers
Dispensers of foaming soap are designed with a special valve that releases air into diluted liquid soap as it is dispensed, causing the soap to emerge as a foamy lather. Manual foaming soap dispensers also come in two varieties: disposable and refillable.
Disposable Manual Foaming Dispenser
These dispensers typically have a shorter pump than liquid soap dispensers because foaming soap spreads easily and requires a smaller quantity to cover the hands thoroughly. Most foaming soap dispensers eject 1.5 mL per pump. Disposable dispensers have the advantages of being inexpensive and convenient. On the other hand, they create a great deal of plastic waste and appear cheap and unattractive.
Refillable Manual Foam Dispenser
Like their disposable counterparts, refillable manual foaming soap dispensers feature short pumps and eject about 1.5 mL of foam per pump. They come in a variety of shapes, styles, sizes, and colors. The main drawback is that refills of foaming soap are not readily available for purchase in stores.
Automatic Liquid Soap Dispensers
The major benefit of automatic soap dispensers is that they operate without being touched by the user, thus reducing germ transmission risk. They have electronic sensors that detect motion or, in some cases, heat. When activated, these sensors signal the unit to emit a specific amount of soap. Automatic liquid soap dispensers are typically programmed to release 0.7 mL or 0.9 mL. However, most new models offer a variable dispenser setting that allows the user to program a range of volumes, from 0.1 mL to 4.5 mL or more.
Automatic Foaming Soap Dispensers
Automatic foaming soap dispensers for household use are also usually programmed to release 0.7 mL or 0.9 mL. With automatic liquid soap dispensers, most of them can be programmed to release a broad range of volumes to meet the user's needs. Because foaming soap lathers and covers the hands more readily than regular liquid soap, the upper dispensing limit is usually around 3.0 mL instead of the 4.5 mL upper limit typical of automatic liquid soap dispensers.
How Many mL Of Soap Is Recommended For Handwashing Procedure?
A 2012 study by the Deb Group -- a manufacturer of commercial soap dispensers -- found that the smallest volume of liquid soap that can effectively clean the hands of an average-sized adult is 0.7 mL. However, health experts recommend using 2.5 mL (or half a teaspoon) of liquid soap to get the best results. And, because foaming soap contains less surfactant per mL than liquid soap does, you should use 3.5 mL or more of foam to ensure that your hands are clean. If you don't happen to have a teaspoon handy, just make sure you use enough soap to get a thick lather over the fronts and backs of both hands.
How Long Does A Bottle Of Hand Soap Last?
If you use the recommended amount of 2.5 mL per handwashing, you can calculate the life of a 7.5-oz bottle of liquid hand soap like the one shown below as follows:
- 7.5 ounces = 221.8 mL
- 221.8 mL divided by 2.5 mL per handwashing = 89 handwashings
The average person uses only 1.5 mL of liquid soap per handwashing; so, using the formula above, a 7.5-oz bottle of liquid soap lasts for 148 handwashings. However, using less than the recommended amount of soap exposes you to a greater risk of illness.
Is Foaming Hand Soap More Economical?
Foaming hand soap typically costs slightly more than the same amount of liquid hand soap. However, most people use less foaming soap than liquid soap per handwashing, so you may find foaming soap to be more economical if you are a typical user. Keep in mind, though, that foaming soap is actually just diluted liquid soap mixed with air -- so the same amount of product packs substantially less cleaning power than pure liquid soap. Thus, if you use the amount that health experts recommend -- 2.5 mL of liquid soap or 3.0 mL of foam -- liquid soap is the more economical option.
What Is The Ratio To Make Foaming Soap?
Making foaming soap is actually quite simple. It would be best if you bought a dispenser specifically designed for foaming soap -- with a valve that forces air into the soap during the dispensing process. Then, mix one-part liquid soap with four parts water, fill the container with the mixture, attach the pump, and your foaming soap is ready to go!
How Long Will A Bar Of Soap Last?
The average person uses about 0.35 grams of bar soap in one handwashing. A typical bar of soap weighs 3.75 oz. or 106.3 grams; therefore, a bar of soap lasts for 304 handwashings. It costs about ten times as much to wash your hands with liquid soap than with bar soap. In addition, bar soap is much more environmentally friendly.
Proper handwashing has never been more important than it is now. When using liquid or foaming hand soaps, you should know how much you're getting each time you pump and whether one pump is sufficient to rid your hands of germs effectively. In deciding what kind of soap to use, you have plenty of options, so you can balance your preferences, your budget, and your ecological concerns to select the hand soap that's best for you.
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