The production of reference materials for quality control of Cr(III) a
nd Cr(VI) speciation in environmental samples is described. It concern
s in the first place two lyophilized solutions containing Cr(III) and
Cr(VI) at different concentrations, respectively representative for dr
inking water and filter leaching solutions, and in the second place fi
lters loaded with welding dust. Twenty-four laboratories with experien
ce in the field participated in an intercomparison exercise organized
to validate the suitability of the reference materials and to gauge th
e state-of-the-art of Cr speciation throughout Europe. The outcome of
this exercise is discussed.