Various detergents are used in daily life for tasks such as laundry and washing dishes. The primary components of these detergents are surfactants. Surfactants can interact with both water and oil (amphipathic), and they work at the boundary between the oil and water through “interfacial activity” to remove dirt.

Surfactants have long been produced from animal and vegetable fats; however, owing to advancements in the petrochemical industry, many surfactants derived from petroleum have been developed. However, petroleum is a limited resource and has a large environmental load; therefore, a shift toward the use of renewable vegetable oils is currently underway. Nevertheless, only certain types of vegetable oils can be used as raw materials for surfactants, and they account for only a small proportion of all vegetable oils.

The global population is expected to reach 9.7 billion by 2050. Moreover, as the number of countries with economic growth and standards of living increase, demand for detergents is likely to increase. Therefore, the vegetable oils used as the raw materials must be produced in larger quantities.

The oil palm tree is grown extensively in Southeast Asia, including Indonesia and Malaysia. In these countries, oil palm plantations are often expanded by draining wetlands and cutting down existing forests.

Consequently, forestland in Indonesia and other countries is in decline, and if this deforestation continues, it will contribute to climate change and loss of biodiversity.

The European Union (EU) announced the "European Union Deforestation Regulation (EUDR)" in 2023, and from December 30, 2025, companies will be required to confirm that the production of any cattle, cacao, coffee, palm oil, rubber, soybean, wood, and related products traded in the EU does not cause deforestation. Therefore, significant increases in the production of palm kernel oil (the oil produced from the seeds of the oil palm that is often used as a raw material for surfactants) and coconut oil are likely to be difficult in the future.

This may lead to a shortage of raw oil materials and an inability to manufacture surfactants, making current laundry standards impossible to maintain. Based on this critical view of laundry in the future, Kao aimed to develop a new raw vegetable oil material.

The main raw materials used to produce surfactants are palm kernel oil, which is extracted from the seeds of the oil palm, and coconut oil, which is extracted from coconuts. However, these oils only account for approximately 5% of all vegetable oils. Palm kernel oil and coconut oil contain many triglycerides with 12 or 14 carbon molecules and are called laurin oil. By contrast, the remaining 95% of all vegetable oils contain triglycerides with 16 or 18 carbon molecules and are called olein oil.

Vegetable oils are broken down into fatty acids, from which higher alcohols can be obtained. Surfactants are prepared using these fatty acids and higher alcohols as raw materials. Surfactants contain a hydrophilic group that is attracted to water and a hydrophobic group (lipophilic group) that is attracted to oil. The fatty acids and higher alcohols provide the hydrophobic groups. As the number of carbon atoms in the hydrophobic group increases (i.e., as the hydrocarbon chain becomes longer), the hydrophobic group becomes more strongly attracted to oil. However, although this improves the function of the surfactant, it also makes the surfactant less soluble in water. The hydrophobic groups in surfactants made using laurin oil have a suitable length. However, the hydrophobic groups in surfactants made using olein oil are longer, which makes them less soluble and unsuitable as a raw material for surfactants. Given this tradeoff between water solubility and interfacial activity, high levels of both are difficult to achieve.

Despite this dilemma, Kao considered the future when focusing on olein oil, which has not been used as a raw material for the production of surfactants in the past. The liquid portion of palm oil (mainly triglycerides containing oleic acid), which constitutes approximately half of the total volume, is generally used for food applications. Kao decided to use the remaining solid part, which is readily available and does not compete with food, to produce surfactants.

Conventional surfactants contain a hydrophilic group at the end of a hydrocarbon chain. However, when producing surfactants from olein oil, the hydrophilic group is at the end of a long hydrophobic carbon chain, and the resulting surfactant has low solubility in water. Therefore, Kao altered the molecular structure by relocating the hydrophilic groups inside the hydrocarbon chain.

After years of research, the following manufacturing process was developed. First, higher alcohols are produced from vegetable oils. These higher alcohols are then reacted to form an alkene with a double bond in the carbon chain (internal olefin), which is the precursor for the surfactant. Chemical reactions, including sulfonation and neutralization, are then used to synthesize the surfactant (internal olefin sulfonate). The hydrophobic group is the hydrocarbon chain of the vegetable oil, and the hydrophilic group is created through sulfonation.

The surfactant synthesized by this method is called "internal olefin sulfonate (IOS)," and it is classified as an anionic surfactant.

Unlike conventional surfactants, Bio IOS has a unique structure with the hydrophilic group inside the hydrocarbon chain. By inserting the hydrophilic group in the middle of the hydrophobic group, the molecule gains a folded hairpin structure in which the hydrophobic group is divided into 12-carbon and 4-carbon hydrocarbon chains. The longer chain has the same length as the hydrophobic group in conventional surfactants, which gives it a similar function. With this structure, Bio IOS realizes high solubility, despite possessing a long hydrocarbon chain that typically does not dissolve well in water.

Compared to other surfactants, Bio IOS dissolves well in water and exhibits high interfacial activity, even in small quantities.

Bio IOS allows the underutilized solid oil extracted from the pulp of palm oil fruit to be utilized effectively. In 2009, Kao developed a concentrated type of liquid laundry detergent (Attack Neo). Subsequently, in 2019, Bio IOS was formulated into the concentrated laundry detergent Attack ZERO.

Kao also proposed a new laundry style to reduce the environmental burden in partnership with consumers through the use of one rinse cycle, which received the Minister of Economy, Trade, and Industry Award at the 12th GSC Awards.

The surfactant in this product was made using palm kernel oil (oil extracted from the seeds of the oil palm) as the raw material, whereas Bio IOS was made using palm oil (oil extracted from the pulp of the oil palm fruit), which had not previously been used as a raw material. In addition, Bio IOS exhibits high cleaning performance in small quantities, making it possible to reduce the amount of surfactant used. Therefore, the amount of palm oil fruit required to produce Attack ZERO was half of that required for Attack Neo.

In addition, in the lifecycle assessment (LCA), which covers the procurement of the raw materials, manufacturing, and disposal, the environmental load was significantly reduced. In particular, the carbon dioxide emissions were reduced by approximately 33% compared to those of conventional products.

The development of Bio IOS, which began with basic research, was a major project that involved a large number of employees and took more than ten years to reach commercialization. The successful realization of a product was the result of hard work and cooperation by many employees from various divisions, including the research and development and production technology divisions.

Bio IOS is now also used in body soap, and we hope to promote its use by more people and expand to overseas markets. In regions with hard water and cold winters, such as Europe, warm water is generally used for laundry because detergents do not dissolve easily. However, Bio IOS dissolves well, even in cold and hard water, which can save the energy required to heat the water.

In the United States, the dioxane contained in surfactants is regulated, and various other substances are being regulated worldwide. Therefore, Bio IOS, which is made from vegetable oil, is gaining greater significance. With the aim of realizing a future in which laundry continues to evolve, basic research into Bio IOS is ongoing. Surfactants are used in a wide range of applications other than detergents, such as paints and concrete additives. Therefore, expanding the applications of Bio IOS will contribute to the realization of a sustainable society.