Bitter taste sensitivity solution for fit testing Used with the 3M™ Qualitative Fit Test Apparatus FT-30 Can be used to check face-to-respirator seal on any particulate respirator or gas/vapor respirator with a particulate prefilter For Occupational Use Only Used to test the sensitivity of the respirator wearer to a bitter solution. It is used with the 3M™ Qualitative Fit Test Apparatus FT 30.