Sample type III, B is composed of water to be analyzed for fluoride in the presence and absence of interferences with and without distillation using a specified procedure. Participant laboratories analyzed samples of water analytically. Standard deviations were calculated and are presented. Results of each analysis are presented including the method used. Finally comments on the methods are presented as are summary data tables. It is hoped that the following are provided: a statistical evaluation of procedures, the opportunity for laboratories to be compared, exchange of information, evidence suggesting methods requiring further development,, and a framework for broad evaluations of new analytical methods.