Reserved for the most sensitive processes, such as High Performance Liquid Chromatography (HPLC); very low levels of biological and ionic contaminants.

For reagent and buffer mixtures and preparation of media for bacterial and cell culture; low ionic contaminants that interfere buffering capacity of solutions; less stringent thresholds for organic contamination

For glassware rinsing, heating baths, filling autoclaves or pre-feeding type 1 lab systems