Fit test solution - Bitter taste The choice between the bitter and sweet test kit is a personal one, however a small percentage of the population are unable to detect saccharin in which case the bitter test must be used. 55ml bottle 55ml bottle The choice between the bitter and sweet test kit is a personal one, however a small percentage of the population are unable to detect saccharin in which case the bitter test must be used (Or vice versa) For Occupational Use Only 3M recommends users are face-fit tested before using a respirator and repeated regularly as part of their occupational respiratory protection program Suggested Applications