Product description

The SaTo pan (pronounced SAH-toh, derived from “Safe Toilet”) is an inexpensive innovation designed for poor households in cultures where squatting and pour flush latrines are the norm. It uses a simple trap door design that forms a water seal at the bottom of a pan set into a cement slab over the pit. The water seal reduces disease transmission by insects, reduces odor and reduces the volume of water needed to flush.

Where the product/service is being used


The Problems it attempts to solve or address

Universal access to hygienic sanitation products and services continues to represent a public health challenge of global proportions. Worldwide 2.5 billion people lack sustainable access to improved sanitation, and 1.1 billion still practice open defecation. An estimated 0.8 million children under the age of 5 die each year from water and sanitation-related diseases.[1]

In rural Bangladesh, the number of latrines has increased by leaps and bounds, due to the efforts of the Government of Bangladesh, the Community Led Total Sanitation movement and other factors, subsequently bringing down rates of open defecation. While 97% of people in Bangladesh have access to latrines, 50% of them are unimproved, meaning they do not prevent disease transmission.[2]

Design Approach

The specific design challenge was to overcome the failures of currently available latrine products with an affordable solution that uses very little water.

iDE and American Standard jointly followed a design methodology called human-centered design (HCD). HCD makes no assumptions about potential solutions and does not prescribe them from the outset. Instead, HCD engages with end users to gain insight into their dreams, opportunities, and constraints around a specific problem. HCD then uses those insights, and an iterative design process, to identify solutions that are feasible, viable, and desirable. (IDEO, in collaboration with iDE, ICRW and Heifer International, developed the HCD toolkit in 2009.)

Examples of insights that emerged from the HCD deep dives:

Financial Insight:

  • Households conceptualize upgrading to their ideal latrine in one big leap rather than in incremental improvements over time.

Product Insight:

  • Current latrine pans use too much water to flush and do not effectively block smell, sight of feces, and flies from entering the pit due to the design of the water trap.

Sales Insight:

  • Demand creation is passive. ‘Sit and wait for customers to come to you’ is the main approach to sales for latrine businesses, masons, and hardware retailers.

iDE and American Standard realized that an improved latrine pan could require less water and provide a more positive user experience. In Bangladesh, iDE and American Standard developed and conducted user and feasibility testing. This feedback provided insights that enabled American Standard to developed two functional prototypes, which they shipped to iDE in Bangladesh for field-testing. Based on user feedback, American Standard selected the trap door version.

To support this design work, iDE was funded by the Swiss Agency for Development and Cooperation (SDC) and the Water and Sanitation Program of the World Bank (WSP) through the “SanMark Pilot project in Bangladesh.” American Standard’s product design efforts were funded separately by the Bill & Melinda Gates Foundation.

Technology Used

Material choice:

Unlike typical latrine components, which are made of concrete or ceramic, the SaTo pan uses plastic. Plastic brings several advantages.

  1. The SaTo pan is inexpensive ($1.50 per unit).
  2. The manufacturing can be sourced locally.
  3. It lends itself easily to mass production and economies of scale.

Mechanical design:

The pan features a counterweight trap door that opens upon rapid addition of >0.5 liters of water. The trap retains a small amount of water in the closed position to create a water seal. No change is required in user behavior.

Business Model

Prior to this project, regional plastics manufacturers did not see the sanitation market for the poor as an attractive business opportunity. iDE expanded the SaTo pan technology into a suite of products serving an expanded consumer base. The wider product offering convinced RFL Plastics Ltd., a major regional conglomerate, that sanitation for the poor is a sustainable business.

During HCD, iDE learned that there are many latrine producers in Bangladesh, yet they are isolated from supporting services. iDE jump-started these small producers by providing training, marketing support, entrepreneurial skills, but most importantly, the link to RFL.

RFL now serves as a hub. It connects small producers, and provides them with quality control and product innovation. What were formerly disconnected producers are now a network of independent retailers for RFL’s new sanitation products. The 3,500 retailers, with a presence in every district in Bangladesh, overcome the “last mile” problem, which is notoriously difficult in rural settings.

Additionally, American Standard explored alternate models that included a BOGO offer. For every American Standard Champion toilet that is sold in North America, they donate a SaTo pan.


To date, over 300,000 SaTo pans have been installed in Bangladesh. During iDE’s 9-month pilot phase, the SaTo pan was sold to 30,000 people within the upgradeable “SanBox” latrine system promoted by the “SanMark-Pilot project in Bangladesh.”

Additionally, American Standard launched a cause marketing campaign called “Flush For Good” that introduced the SaTo pan to the general public through television and print advertising, coverage in the Wall Street Journal, and other key media placements, to increase awareness of the global sanitation crisis and making a traditional taboo topic media-friendly.

Lessons Learned

The lesson learned is the value of partnerships between organizations that have complementary skill sets. American Standard opened doors for iDE and vice versa. The combination of American Standard’s product design knowledge and iDE’s human-centered design expertise allowed a transfer of knowledge that went both ways. Indeed, the SaTo pan technology was a kick-start for both organizations.

Contact details

Conor Riggs
Technical Director – Programs
iDE Bangladesh
Skype: conor.riggs

[1] These coverage figures are from a comprehensive analysis of 2006 data by the WHO/UNICEF Joint

Monitoring Programme (JMP) for Water and Sanitation. –

2 Bangladesh Bureau of Statistics (Multiple Indicator Cluster Survey Report 2010) data shows that ‘sanitary’ latrine coverage in Bangladesh is only 51.5%. This is supported by the WHO/UNICEF Joint Monitoring Programme (JMP) for Water Supply and Sanitation in 2010 which puts the coverage figure at 53%.