Fluoride Action Network

Denmark: Substitution of an environmentally problematic substance used in the chrome plating industry

Source: IPU Technology Development | December 1st, 2010
Industry type: Perfluorinated chemicals

An important Danish investigation is on its way to find a replacement for the harmful substance PFOS that is used as a chemical aid in the hard chrome plating industry all over the world. PFOS is harmful to both environment and health. The investigation, which is being financed by the Danish EPA, is managed by FORCE Technology in cooperation with IPU, DTU Mechanical Engineering and the surface treatment company a.h. Nichro Haardchrom A/S that is assisted by the development company SurfCoat A/S.

A general restriction on the use of PFOS (perfluorooctanesulphonate) and other PFOS-based chemicals became effective in Denmark and the rest of the EU in June 2008 due to the fact that PFOS is persistent, bioaccumulative and an endocrine disruptor that is concentrated in animals and humans, and affects our fertility. PFOS is listed on the POP (Persistent Organic Pollutants) list of the Stockholm Convention of especially environmentally dangerous chemicals.

PFOS and other PFOS-based chemicals are surface active chemicals that are used as mist suppressing agents (mist suppressants) within non-decorative hard chrome plating. However, this specific use is exempted from the EU restriction as no suitable alternatives were available at the time of adoption of the legislation. Without the use of PFOS as mist suppressant in the hard chrome plating process, droplets (aerosols) of chromium acid are emitted into the surrounding air of the chrome bath. Chromium acid is a hexavalent chromium compound, which is carcinogenic, allergenic and harmful for the environment. Therefore, the use of PFOS together with exhaust devices is eliminating a potentially working environmental problem in the industry.

The current annual use of PFOS in Denmark as mist suppressant for chrome plating is not large – a maximum of 30 kg. However, on a worldwide basis, the use is more than 30 tonnes PFOS annually. This amount eventually ends up in the environment and creates a globally environmental problem.

The investigation is more than halfway. Alternative solutions have been tested in the lab, and right now the project group is testing a possible alternative on an industrial scale at the chrome plating company Nichro Haardchrom in Hvidovre in Denmark. The results of these investigations are expected at the beginning of 2011.