3M Bitter Sensitivity Solution, Bitter - EachAbout 3M Sensitivity Solution, Bitter (1 Unit) The bitter sensitivity solution helps in checking that there's a safe respiratory seal It's used with the 3M FT 30 Fit Test Apparatus to ensure the respirator meets OSHA standards This solution uses denatonium benzoate to produce a bitter taste It allows organizations to meet regulatory fit testing requirements for respirators This 3M sensitivity solution works with a nebulizer and collar to test the fit