Each bag contains what feels like a little bit of sand. It is actually urea, a chemical found in our bodies but synthetically produced. The urea reacts with the feces to produce ammonia, and that kills the pathogens that can cause diarrhea and cholera. The bag --which is made of biodegrable plastic– also disintegrates, and the contents become fertilizer, which Wilhelmson says can be used to grow vegetables.
Wilhelmson claims that naturally, this process would take at least a year or two, but his toilet reduces the breakdown time to a couple of weeks or even hours. According to him, field tests in the slums of Nairobi have proven successful.
Several women in this area have now signed on to begin selling the toilets, and Wilhelmson hopes the activity will empower them financially. The production cost of these bags is low, which means it can be sold for a starting price of around 3 cents, he says. Wilhelmson is even designing a system of collecting the fertilizer and giving people a rebate for it.
While not perhaps what one might think of as an example of Swedish design, Wilhelmson's invention recently won an award from Svensk Form, or the Swedish Society of Crafts and Design. The organization dates back well over a century. Surrounded by books on the history of Swedish design, Ewa Kumlin, the director, explains that she is impressed by the whole economy that Wilhelmson is creating around his invention.
Could this humanitarian system signal a new tendency in Swedish design?
Kumlin says it is a global trend for designers to try to solve important problems. But she says that Sweden falls into this naturally, because it has a tradition of socially engaged design.
"For the last decades, we have been looking at design as something superficial," says Kumlin. "This is not the basic idea of design. You have the whole spectrum, but it's much broader than that."