When electric washing machines were popularized in the 1950's, synthetic laundry detergents became commonly used. Until then, clothing was washed by hand using solid soap, but the synthetic detergents capable of removing stains well and being easy to use, along with the electric washing machines, drastically reduced labor required for laundry, and quickly became widespread. However, from the 1960s to the 1970s, several detergent-based environmental issues were observed, such as the foaming of river/lake water due to detergent-containing wastewater and eutrophication (due to the phosphorus in detergents) . To resolve these issues, biodegradable detergents, phosphorous-free detergents were developed. In the 1990's,global environmental problems were brought to public attention, and further environmentally benign products were desired from a number of viewpoints such as resources and energy. Since then, each manufacturer not only contributes to a comfortable lifestyle or improvement in convenience, but also addresses manufacturing of products for realizing a sustainable society.

Kao Corporation has engaged in making products having low environmental impact from early on, such as starting the development of refill products ahead of other companies. In the late 1980's, the company developed compact powder detergents for clothing capable of carrying out laundry with a smaller amount of detergent, and in the 2000's, had a concept of making liquid detergents compact upon developing the next product. Making the products compact has economical advantages such as reductions in packaging materials and transportation energy, and also leads to a reduction in environmental impact. However, the company did not stop at making the products compact, but also discussed how to add environmental values to the products from a broad perspective.

Kao Corporation used LCA to assess and improve the environmental value of their products in the entire laundry system (from the laundry process to disposal). LCA involves environmental-impact evaluation throughout the life cycle of a product, from raw-material procurement to product design/manufacturing, transportation, use, and disposal . The findings indicated that the environmental impacts were almost the same between the part related to the product from manufacturing to disposal, and the part related to the use of detergents during laundry. Furthermore, 65% of the carbon dioxide emissions related to detergent use can be attributed to the water used during laundry.

Japan is believed to be a country with a lot of rain and rich water resources, but the resources are limited. Japan has many slope lands and short rivers, which cause rain water to flow immediately out to sea, preventing much of the water from being utilized. Furthermore, a large amount of energy is required to transport water from water-purification plants to households and from households to sewage. A reduction in water usage for laundry can reduce the environmental impact of the laundry process. However, prior to the technology developed by Kao Corporation, no products were manufactured to reduce the amount of water used for laundry.

The company worked on the development of a product capable of reducing the amount of water used for rinsing. Merely reducing the amount of water used in one rinse cycle causes the washing machine to stop rotating. Therefore, the amount of water used for one rinse cycle was left unchanged, and the number of rinse cycles was reduced from two to just one.

In order to make liquid detergents compact, the liquid detergent needs to be concentrated. To reduce the rinse cycle to just one time, a technology is required for quickly washing out the detergent remaining in the clothing, without decreasing detergency. Accordingly, the development team took on the challenge of developing a technology for simultaneously achieving ultra-concentration and high rinsing property while retaining detergency.

First, ultra-concentration can be achieved by reducing the water content that occupies more than half of the liquid detergent. However, a water-content reduction solidifies the detergent, making its dissolution in water challenging. This presents an antinomic technical challenge.

Surfactants comprise molecules with hydrophilic (compatible with water) and lipophilic (incompatible with water) groups. Reducing the water content of a liquid detergent causes the surfactant molecules in the detergent to stack up (facing the same direction), forming a layer structure (left-hand-side image in the figure below). This reduces the contact area of the hydrophilic groups with water, making the dissolution of the surfactant in water challenging.

Then, the development team searched for a surfactant that does not solidify even in a concentrated state by examining various surfactants, referring to the principle shown in the phase diagram which indicates properties of the surfactant and so on, and finally found a suitable surfactant. Little attention had been paid to this surfactant in terms of detergents for clothing, but it was found that the surfactant would satisfy the targeted properties after modifications were made. The development team enlarged the part of the hydrophilic group within the molecules to prevent the surfactant from forming the layer structure, allowing the surfactant to be mixed with water more easily, and slightly changed the shape of the hydrophilic group to prevent the molecules from aggregating (Right image in the figure above). The thus formed surfactant having high hydrophilicity was used as a base in combination with a conventional surfactant, enabling a state of being dissolved in water to be maintained even in a small amount of water, and the liquid detergent that had previously been 1 kg was successfully concentrated down to 400 g.

A surfactant having high hydrophilicity that hardly remains in the fibers of clothing is suitable for increasing rinsing power. On the other hand, a surfactant having high lipophilic properties compatible with clothing stains such as sebum is more suitable for improving detergency. This presents an second antinomic technical challenge. To resolve this issue, the surfactant having high hydrophilicity was combined with the conventional surfactant having a good stain- removing effect to exhibit larger effectiveness.

When these two types of surfactants are combined, mobility of the surfactant molecules is increased, and the molecules quickly move towards the stain in the cloth. When the molecules surround the stain and form a spherical micelle Self-organization), the micelle became immediately separated from the cloth due to its high hydrophilicity. The developed surfactant shows excellent rinsing properties and high detergency, comparable to conventional detergents (as confirmed by a verification test). Thus, a brand-new type of detergent was born.

The Kao product was released as "Attack Neo" in 2009. The company succeeded in concentrating liquid detergents for the first time in the world, and making the product compact resulted in the reduction of transportation cost and packaging containers for liquid detergents. Since the detergents exhibit high detergency with a small amount, the amount of use of the detergents is reduced, which enables the influence of waste water on the environment to be reduced as well.

Furthermore, the unique proposal of "just one rinse cycle" surprised consumers. As two- rinse cycles　are common in Japan, washing machines are generally designed on this premise. Therefore, a team from Kao Corporation examined washing machines from different manufacturers and proposed a method to operate one-rinse cycles.

At first, the one-rinse operation bewildered many consumers. However, this concept has been completely accepted with time, and new washing machines contain a button for one-rinse cycling. The utilization of one-rinse cycles has reduced laundry time considerably, increasing the spare time available to individuals and organizations.

This technology has also changed the impact on the environment. When the number of rinse cycles is reduced from two to one, both the amount of water and electricity used by a standard household using a top-loading-type washing machine are reduced by 22%. An LCA at this stage indicates 21% and 22% reductions in CO₂ emissions at the product and household levels, respectively, with a total CO₂-emission reduction of 21%.

Thus, this technology that received the GSC Award introduced a new concept in which the environmental impacts are reduced not by the products alone but by working together with the consumers. It gave us consumers an opportunity to think about water and the environment and to take action.

Kao Corporation is refining this technology further to improve the detergency, reduce the laundry time, and use recyclable raw materials. The technology is becoming more and more advanced for realizing a sustainable society.