OTHER METHODS: Method 7703 is a field portable method for Cr(VI). OSHA Method W4001 is for the measurement of Cr(VI)
in wipe samples [4]. OSHA Method ID-215 is for measurement of Cr(VI) and employs precipitation to reduce Cr(III) oxidation. [5]. A similar air method is ISO 16740 [6]. EPA Method 218.6 is for water matrices [7]. Method 7604 is also specific for hexavalent chromium, using ion chromatography, but has a higher detection limit than 7605.