Chemists Without Borders solves humanitarian problems by mobilizing the resources and expertise of the global chemistry community and its networks. The most common problems include poor water quality, maldistribution of medicines and vaccines, and lack of chemical education. Chemists Without Borders focuses on duplicating and providing proven solutions. Entrepreneurship is built into our programs as much as possible so that those we help can become more prosperous and help others. Recent and current projects include validation of a composite-iron-matrix arsenic-removal water filter, field verification of a low cost, low tech arsenic measurement device, provision of water filters for rural Bangladesh, and designing secondary science lab exercises for Sierra Leone.