For much of the world, sanitation is still a grim business. Some 2 billion people, close to a third of the global population, lack basic sanitation facilities. Of these, 673 million still practice open defecation, meaning that they do not use any toilet at all, and hundreds of millions use facilities shared by multiple families—which are hard to keep sanitary. Poor sanitation is a major public health challenge, causing more than 280,000 deaths annually, while contributing to nearly half of undernutrition worldwide. Poor sanitation makes it hard to keep any valuable foods down. It is also the cause of enormous economic losses, estimated at US$200 billion annually from stunted cognitive development of children, as well as direct health care costs. Firmenich, the second largest flavour and fragrance company in the world, co-sponsored a study with the Bill and Melinda Gates Foundation on malodour and sanitation decision-making in low-income communities.