About 2.5 billion people worldwide don't have access to sanitary toilets. Latrines are an option for many of those people, but these facilities' overwhelming odors can deter users, who then defecate outdoors instead. To improve this situation, fragrance scientists paired experts' noses and analytical instruments to determine the odor profiles of latrines with the aim of countering the offensive stench. Their report appears in the ACS journal Environmental Science & Technology.