Science of Soap: 'Clean Tech' Innovation Prevents Infection, Saves Lives

Washing hands with soap is a proven way to prevent the spread of life-threatening diseases, especially among children.

Yet for millions of people living in developing countries, safe and durable hand soap is not widely available. As a result, handwashing doesn’t make its way into daily routines as often as it should — and health suffers.

A collaboration between the Dow POLYOX™ Polymers and Unilever Lifebuoy™ soap R&D teams has helped to change this reality by bringing high-quality and long-lasting soap to these underserved markets.

Driving the project is a mission to reduce mortality rates and prevent the spread of illnesses that keep kids out of school in developing countries. From thwarting diarrheal infections — which claim the lives of 1.87 million children under the age of five each year, according to the United Nations Children’s Fund (UNICEF) — to averting serious illness such as eye infections, influenza and pneumonia, soap is simply one of the most straightforward and cost-effective ways to remain healthy.

However, the reality is that for many people in developing economies such as India and Latin America, hand soap remains a luxury item. For people to consider buying a bar of soap, the product must be perceived as an exceptional value: It must remain intact for as long as possible, feel pleasant to the touch and avoid dryness or irritation after washing.

Unilever approached Dow for assistance in finding a cost-effective way to differentiate the performance of its soap brands — a change that would make the soap last longer, feel good to use, and prevent uncomfortable dryness afterwards. Unilever sought to appeal to value-conscious consumers in parts of the world where opportunity for health impact was highest.

“A bar of soap is a complicated thing,” says Curtis Schwartz, associate director of Personal Care Research & Development at Dow. “It sounds so mundane because bars of soap have been around for such a long time. But if you change even one variable in the formulation, you risk changing a lot of other things, usually for the worse. Cracking, brittleness, mushiness - these are the things that could result with any additive to the bar soap that risks changing its phase chemistry.”

Dow scientists working with Unilever defined the scientific challenge, which was chiefly to increase the stability of Unilever’s bar soap. “If the soap gets mushy or breaks, consumers won’t consider it to be a good value,” Schwartz said. “People in these markets don’t have a lot of money to spend.”

Dow researchers explored the technical problem and looked at adjacent industries where similar problems were solved. POLYOX™ Water-Soluble Polymers from Dow are used widely in controlled-release applications for the health and hygiene markets, as a film former and binder with good lubricity properties. The Unilever team began looking at ways to apply this technology to a bar of soap. “A bar of soap must stay intact while releasing ingredients slowly and at the right time,” Schwartz said. “The team made an important connection.”

After a range of tests incorporating POLYOX Polymers into the soap at various levels, the Unilever scientists arrived at bar soap with great performance that was affordable to the market they were targeting.

“The soap has a really nice feel,” Schwartz said. “The polymer design helps structure the bar improving its dimensional stability, and in-use properties. The beauty of the solution is that it does so extremely efficiently, at a low enough level in the bar to be affordable to the target market. It all comes back to good science, and that’s what Dow is really good at.”

The end result, Lifebuoy™ Soap featuring POLYOX Water-Soluble Polymers, is now a reality, bringing affordable hygiene to the most economically challenged strata of society.

The soap, in its signature red color, is sold in emerging markets like India at a cost of $0.10 USD per bar (approx. 30–35 grams). Unilever rolled out the new formulation first in Brazil, Thailand and Indonesia. Unilever then introduced it to the Indian market, in concert with a strong, successful push for its hand-washing campaign in Thesgora, India, which had one of the country’s highest rates of diarrhea.

“POLYOX was instrumental in helping Unilever break the value paradigm in the world of soaps by continuing to offer a soap bar at 10 U.S. cents,” said Peter Gallagher, Unilever’s vice president of Research & Development for Global Skin Cleansing.

Unilever awarded Dow with “Partner to Win – Innovation” Award, given to suppliers whose projects have impacted the market with innovations that have delivered better overall product functionality, speed to market and increased appeal to consumers.

As events such as Global Handwashing Day seek to raise awareness of the benefits of handwashing with soap — and its power in saving lives — it’s good to know that a bar of soap is commercially available to help make this daily routine possible for the people who need it most.