Determining Soap Quantities For Proper Handwashing

One Size Doesn’t Fit All

So what is the appropriate amount of soap needed in order to wash hands properly? The answer to this question varies widely, depending on who you ask. Some facilities are reducing the amount of soap dispensed to 0.4 ml — not enough to get the job done, according to some dispenser manufacturers.

Schneringer offers a range of soap dispensers with various shot sizes, including 0.7 ml, 0.9 ml, and even 1 ml. He also sells an adjustable dispenser that can be set to dispense 0.7 ml or 0.4 ml. According to Schneringer, manufacturers alter soap shot sizes at the request of the customer.

“It’s a market-driven response,” he notes. “It’s not in a manufacturer’s interest to limit the amount of product going through a dispenser.”

Some believe that limiting the amount of soap dispensed has the same effect as buying cheap soap. Facilities save money up front but could end up paying more in the long run.

“You often hear people say ‘soap is soap,’ but fortunately, that’s not the case,” says Mann. “As a chemist, I spent many days formulating hand soaps, and there are so many dimensions to a good one. You want a good feel, you want foam, and you want one that rinses easily. The difference in price between a cheap soap and a good soap is infinitesimal in the overall cost of maintaining an atmosphere of wellness.”

A good, quality soap that lathers easily may be effective when dispensed in smaller amounts. Likewise, facilities tend to get more mileage out of foam soaps.

“We favor foam because it helps distribution [on the hands],” says Mann. “People tend to use higher quantities when they use a liquid soap.”

Schneringer concurs: “With a foam soap dispenser, 0.4 ml feels like it’s enough soap to cover your hands, whereas with a liquid soap, it may not feel like enough,” he says. “Part of this might be purely psychological, and part of it might be the physical characteristics of the foam already representing some lather. Sometimes liquid soap doesn’t appear to be enough and the user hits the dispenser again, or the soap just rolls off their hands and they have to get more.”

While formulation and type is important to determine how much soap is enough, cleaning managers also need to look beyond the soap itself. The size of the end user’s hands should be factored into the equation, as well as the type of soil and the environment in which the soap is being used. 

“How much soap to use depends on what industry you’re using it in,” says Strain. “Is it a medical setting or an automotive garage? You might use different dispensing amounts in each of those applications.”

Sizing Up Sanitizer

Like hand soaps, hand sanitizers are dispensed in amounts predetermined by the manufacturer. Typically, building occupants need only one shot of hand sanitizer to properly disinfect their hands — about the size of a quarter, according to Saul Strain, vice president of ABC Sales & Services, headquartered in St. Thomas, Virgin Islands.

While users are more likely to overuse soap than hand sanitizer, there is also the danger that they might not be using enough.

“Sometimes people don’t want to take a full dose because they’re in a hurry and they want it to dry quickly, so they start shortchanging the dose,” says Mann. “That’s a no-no. If you cut that portion down, you’re going to compromise the kill factor.”

A good rule of thumb: Make sure building occupants have enough hand sanitizer to cover both hands and keep them wet for 15 seconds.