In times of health emergencies and humanitarian disasters where water is scarce, people worldwide have relied on the Tippy Tap. It's a DIY hand-washing station developed by aid workers that can be made fast with readily available materials: sticks, string and a water container.

But for heavy-duty use — washing up several times a day during a pandemic that has stretched beyond a year, for example — a makeshift Tippy Tap just won't cut it.

Unfortunately, even with new innovations, there is no one-size-fits-all hand-washing solution for every crisis, says Michelle Farrington, a public health expert at Oxfam, an international aid group that has been implementing alternatives to the Tippy Tap.

And no hand-washing station can fix the biggest problem: reliable and convenient access to clean running water, says Myriam Sidibe, a hand-washing expert and senior fellow at the Harvard Kennedy School.

New designs in hand-washing taps still require bringing water to fill the stations. But they attempt to address the shortcomings of the Tippy Tap, such as ease of use, durability and encouraging proper hand hygiene to reduce the spread of the coronavirus.

Here are two taps being put to the test during the pandemic.

Oxfam's hand-washing station

The Oxfam tap was created as an alternative to the Tippy Tap to use in dire circumstances, such as refugee camps.

Made mostly from durable plastic, the pale blue, 6-gallon tank has a lockable lid with a mirror that sticks on and a 1-gallon soap dispenser that can wash up to 200 pairs of hands.

To activate the brass tap, you simply push up on the tap and a sprinkle of water is released.

Beneath the tap is a bright green tray that can hold bars of soap and keeps the water from hitting the ground and getting your feet wet.

The tray is attached to three steel legs that can be cemented into the ground to prevent theft, which is a big concern for installing public taps.

The idea was inspired by U.K. schoolchildren in 2015 in response to an Oxfam challenge to design hand-washing stations.

Just like a Tippy Tap, the Oxfam station is designed for emergencies. Its six parts are compact, making shipping many units at once efficient. It can be assembled quickly and easily.

In refugee camps in sub-Saharan Africa and Bangladesh, Oxfam has rolled out nearly 4,000 of its new hand-washing stations as an alternative to the ubiquitous Tippy Tap.

Oxfam has studied the behaviors of those using its new hand-washing stations. In December 2017, it piloted them in the Kyaka II refugee camp in Uganda. Researchers collected survey data from 147 households with the Oxfam stations along with 89 households using an older station that consisted of a bucket fitted with a tap. They found that while hand-washing increased irrespective of which station was used, households with the new station were more likely to recognize the importance of clean hands at critical times such as after using the latrine and before cooking or feeding children.

At a cost of nearly $70, the Oxfam station is affordable and doesn't require power to operate, says Farrington.

On the downside, the Oxfam tap requires touching it with your hands to activate the tap or dispense soap, says Sian White, a researcher in behavior change and hygiene at the London School of Hygiene and Tropical Medicine. This could result in getting the virus on your hands while you wash if it has been touched by many dirty hands.

And because all the parts are imported, it may take time to deliver the stations to places that need them most, she adds.

Despite these disadvantages, White says this is a better alternative than a Tippy Tap because it's durable and also attractive, a factor that is often overlooked when designing products for a humanitarian setting.

SolaWash

The SolaWash is a hand-washing station that is both touch-free and solar-powered, invented in Ghana at the beginning of the pandemic.

Richard Kwarteng, 33, a shoemaker by trade, didn't like what he saw when people were washing their hands with communal buckets and taps in his neighborhood in Kumisa, one of Ghana's largest cities. They were touching the water dispensers, risking contamination. And they weren't lathering up for the suggested 20 seconds.

So he came up with a new kind of hand-washing station. It uses a 66-gallon steel oil drum as its base with three compartments inside to hold soapy water, rinsing water and wastewater. This is connected to a metal sink that sits on top of the barrel.

It's touch-free. When you put your hands beneath the tap, they are detected by a sensor that is powered by solar panels above the sink. First, soapy water is dispensed, followed by beeping sounds for 25 seconds – an ideal hand-washing time. Then about two cups of water come out of the same tap for rinsing.

Kwarteng wanted it to be attractive, so he repainted the drum with the flag of Ghana: red, yellow and green with a black star in the center.

A full tank of water – about 600 cups — can wash up to 280 pairs of hands. In some locations it is connected directly to a water source, but in the rural areas, it must be filled by hauling water to it.

Delivered as a pre-assembled unit, SolaWash is made with mostly locally sourced materials. The solar panels are the only major component that must be imported.

"It is simple to operate by lay people," says Francis Akpaloo, the Ghanaian government engineer who tested and approved the product for commercial use. "And it teaches people the need to be hygienic and conscious of COVID-19 and to always wash your hands."

There are 150 SolaWash units located throughout Ghana, Kwarteng told NPR by phone, that were purchased through private and nonprofit partnerships for public use. Oxfam purchased 30 of the stations for health clinics.

While the touch-free technology is perfect for the pandemic and is attractive, says Farrington, it has its drawbacks.

The unit will require a repair person with special skills if the sensor or solar panel breaks down, which is an additional cost.

And not only will it require water to be transported to refill it, just like a Tippy Tap, it will also need to be drained of wastewater.

For a pandemic solution, it's a substantial improvement over a primitive Tippy Tap, says Franklin Amuakwa-Mensah, an environmental resource economist and researcher at the University of Gothenburg in Sweden. The automation and timing of each step of the hand-washing process reminds people to lather their hands for a sufficient amount of time without wasting water or soap, while using a sustainable power source.

Nothing like the real thing

Despite all the bells and whistles featured in a SolaWash and even the Oxfam station, experts agree the best solution is clean, running water.

A hand-washing station is a Band-Aid for people with limited water who need to wash their hands as a critical protective measure against disease, say the experts. It doesn't solve the fundamental problem of access to water, which Sidibe says is the biggest barrier for clean hands.

"Nothing beats a sink and running water. That's the reality," says Sidibe. "The problem with hand-washing stations is you still have to bring the water [to it]. You can have all the motivation, but if there is no running water it makes it absolutely difficult to wash your hands."

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