Nitrogen fertilizer is a cornerstone of modern agriculture, but the rising costs of key ingredients, including nitrogen itself, have made it more expensive than ever. One company believes it has found a more sustainable, affordable way to make fertilizer — by recycling human urine.

Aurin is a universal fertilizer from Swiss company VunaNexus made with processed human urine. It originated as a South African research initiative launched more than a decade ago to develop an affordable sanitation system that could transform human urine into fertilizer.

 “The fertilizer has the same effect as other fertilizers, it’s completely depolluted, and it doesn’t smell — people always ask about the smell,” says David de Chambrier, co-founder of VunaNexus. Aurin has already been approved for use in several European countries and, de Chambrier reports, is now being shipped to the United States.

Using human urine as fertilizer may sound surprising, but the idea is more practical than it first appears. Sustainability experts say products like this could play an important role in reducing waste and recovering valuable nutrients. Here’s why.