Designed for testing low concentration peroxide solutions ( It matches at 0, 1, 3, 10, 50, and 100ppm Stiff, plastic strips offer durability Certificate of analysis available upon request Includes: (50) Strips Low Level (LL) Peroxide strips test for residual peroxides in concentrations under 100ppm. They are primarily used for testing things like drinking water. The strips are calibrated at 0, 1, 3, 10, 50, and 100ppm. These LL Peroxide test trips are suitable for semi-quantitative hydroperoxides and ether peroxides. Polymeric peroxides are not detected. Di-tert-butyl peroxide, dicumyl peroxide, or tert-butyl perbenzoate do not react (or will react with significantly reduced sensitivity).