Uniting a global WASH response with an evidence-based approach: the WASH Severity Classification Format When the Integrated Food Security Phase Classification (IPC) was originally created in 2004, the impetus came from the humanitarian community’s need to understand food security crises faster and with greater precision, so as to shape a more effective response. The IPC has since then become a landmark in the fight against food insecurity. Decades later however, a similar approach- where vast and various data sources are fed into a recognized and trusted analysis system- has yet to emerge in the Water, Sanitation, and Hygiene (WASH) sector. With this in mind, a new inter-agency global initiative was launched, with the support and early buy-in from over twenty aid organizations. As the pilots of this new approach have yielded their first results, we are glad to introduce the new WASH Severity Classification (WSC).