Clever Soap For A Cleaner Future
The ubiquitous soap occupies the least space in any household, and a large part of human perception about hygiene and notions of beauty. According to industry reports, the global size of the soap market was valued at $48.05 billion in 2024, projected to reach a whopping $76.45 billion by 2032. In terms of scale, this amounts to the Gross Domestic Product (GDP) of Nepal, Afghanistan, Maldives and Bhutan put together.
In an invigorating talk titled ‘Soap – A Continuing Sustainability Journey’, the Department of Chemical Engineering hosted Dr. Janhavi Raut, Principal Research Scientist at Unilever R&D, where students and faculty were treated to a bevvy of information about the history and chemistry of soap.
Bursting the bubble of popular notions, Dr. Raut noted that humans’ fixation with soap began around 7,000 years ago, when the Sumerian civilisation in southern Mesopotamia (modern-day Iraq). Initially, to be used in making textiles, it was around 5,000 years ago that Egyptians began adding essential oils and herbs to soap to be used for fragrance and medicinal purposes.
The science of soap-making, since then, gradually evolved into a process called saponification during the Industrial Revolution. It was just two decades after the tectonic shift in manufacturing that Alfred Nobel stumbled upon glycerol – a byproduct of saponification – to discover dynamite that changed the course of world history.
Using the analogy of brick and mortar for a soap’s microstructure, Dr. Raut explained the bricks as a long chain of insoluble fatty acids that give structure and rigidity to the soap, while the mortar is composed of shorter-chain, soluble molecules responsible for lather and cleaning.
Highlighting that traditional soaps often contain a high proportion of these structural components, Dr. Raut said that reducing these proportions is the key to making soap manufacturing sustainable by cutting down the use of oils. In recent times, the cheap cost of palm oil has led to the deforestation of over 10-15% of rainforests around the world.
“Conventional soap bars often consist of a very high fraction of bricks, over 70% of total fatty matter (TFM) can be in this structural fraction. To address this inefficiency, up to 25% of non-functional TFM is being replaced with plant-derived polysaccharides, vitamin blends, and other skin-benefit actives. This innovation reduces reliance on palm oil, lowers greenhouse‐gas emissions, and delivers a soap that performs as well as the traditional high-TFM bars,” said Dr. Raut.
To a question from the audience on why powdered soap or liquid soap couldn’t replace soap bars, Dr. Raut said, “Powdered soap is still a niche category and requires significant time for market development. Liquid soaps also have limited consumer demand in comparison to bar soaps. In addition, liquid products require expensive packaging and often contain synthetic surfactants that carry their own environmental risks.”
Dr. Raut’s talk highlighted the disquiet around a soap and the rising scientific and global pressures to give this essential commodity a sustainability-driven redesign. For a product that has shaped human hygiene for millennia, its next chapter may be defined not just by how well it cleans, but by how gently it treats the planet.