3M Bitter Sensitivity Solution FT-31 3M Product Number FT-31, 3M ID 7100004635 · · · Replacement bitter tasting sensitivity solution for 3M Fit Test Kit FT-30. · · 55ml bottle · · Test kits and accessories are designed to help your organisation meet regulatory fit testing requirements for respirators. · · The products can be used to check face to reapiator seal on any particulate respirator or gas/vapour respirator with a particulate prefilter. · · Sweet or bitter taste sensitivity solutions for fit testing · · 3M recommends users are face-fit tested before using a respirator and repeated regularly as part of their occupational respiratory protection program