World Toilet Day 2021: Valuing Toilets

World Toilet Day 2021: Valuing Toilets

World Toilet Day is a day of observance every November 19th, initiated by the United Nations, to spread awareness of the global sanitation crisis. According to the UN, 3.6 billion people – approximately 46% of the world population – do not have access to safely managed sanitation [1]. The Joint Monitoring Programme For Water Supply, Sanitation, and Hygiene (a joint initiative between the World Health Organization and The United Nations) defines “safely managed sanitation” as the “use of improved facilities that are not shared with other households and where excreta are safely disposed of in situ or removed and treated offsite.” 

Unreliable access to a toilet is more than a mere inconvenience, as safe sanitation is critical to health and safety. The UN’s official World Toilet Day website reports that over 2 billion people in the world today use a drinking water source that has been contaminated with human solid waste. This leads to hazardous health conditions, which can result in illness and even death.

The UN states that “every day, over 700 children under five years old die from diarrhea linked to unsafe water, sanitation and poor hygiene” [2]. To address this complex issue, the United Nations established Sustainable Development Goal 6, an effort to “ensure availability and sustainable management of water and sanitation for all” by 2030. To achieve this, “we urgently need massive investment and innovation to quadruple progress all along the ‘sanitation chain’, from toilets to the transport, collection and treatment of human waste” [1]. 

What does World Toilet Day have to do with spotLESS Materials?

spotLESS Materials core technology was developed specifically to help address this sanitation crisis. Before spotLESS Materials was formed, a group of mechanical engineers and materials scientists at the Wong Laboratory for Nature Inspired Engineering at The Pennsylvania State University was hard at work making what would become the most poop repellent coating technology available today. In 2011, the Bill and Melinda Gates Foundation launched the Reinvent the Toilet Challenge [3], a challenge aimed at addressing the global sanitation crisis.

They funded 6 teams to create a bathroom system for regions lacking modern sanitation infrastructure. One of these teams recognized a major sticking point: many regions experiencing a sanitation crisis are also experiencing a water crisis. Managing waste with little to no water would mean solid waste sticking to the system. In an effort to find a slippery solution, they reached out to Prof. Tak-Sing Wong, who is known as a key inventor of SLIPS [4] – a groundbreaking slippery coating technology he developed as a Harvard postdoc. Seeing an opportunity to make a positive impact, Tak-Sing and his team got to work.

The result of this hard work, spearheaded by Prof. Tak-Sing Wong and his PhD student Jing Wang, was an impressive coating that could repel human waste more effectively than Teflon, silicone, and other highly repellent surfaces [5]. They called this technology LESS – the “Liquid Entrenched Smooth Surface.” Compared to untreated glass, the coating could repel 90% more “viscoelastic solids” (i.e., poop). Any residues that attached to the surface could be washed away with 90% less water [5].

Around this time, one of Tak-Sing’s PhD students, Birgitt Boschitsch, had a growing passion for seeing technologies, like the ones she and her colleagues had been developing in Tak-Sing’s lab, realize their potential for positive real-world impact. For her, making a technical solution to a global problem was step one in the journey towards impact. Step two, would mean getting that technology off the bench and into the hands of the people who would benefit from it. So impassioned to address global challenges and equipped with deep technical expertise, Birgitt and Tak-Sing founded spotLESS Materials.

spotLESS Materials launched its Toilet Coating and Home Collection November 2019, offering their products to anyone eager to keep their bathrooms clean. But this is just the beginning. Sticky problems are everywhere, and spotLESS Materials wants to tackle them with their tech. Birgitt and Tak-Sing started spotLESS Materials because they wanted to use their skills and technology to do something good for others. That goal continues to be the driving force for the spotLESS Materials team.



  1. World Health Organization. "Progress on household drinking water, sanitation and hygiene 2000-2020: five years into the SDGs." (2021).
  2. UN-Water. "World Toilet Day." Accessed November 18, 2021.
  3. "Reinvent the Toilet Challenge: A brief history." The Bill and Melinda Gates Foundation. Accessed November 18, 2021. global-growth-and-opportunity/water-sanitation-and-hygiene/reinvent-the-toilet-challenge-and-expo.
  4. Wong, Tak-Sing, Sung Hoon Kang, Sindy KY Tang, Elizabeth J. Smythe, Benjamin D. Hatton, Alison Grinthal, and Joanna Aizenberg. "Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity." Nature 477, no. 7365 (2011): 443-447.
  5. Wang, Jing, Lin Wang, Nan Sun, Ross Tierney, Hui Li, Margo Corsetti, Leon Williams, Pak Kin Wong, and Tak-Sing Wong. "Viscoelastic solid-repellent coatings for extreme water saving and global sanitation." Nature Sustainability 2, no. 12 (2019): 1097-1105.
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