Metal finishing Q&As since 1989

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Does Alodining Violate EU ban of CrVI

2004

Dear Sirs:

I inquire if someone can advise does the "Alodining" process contain the EU banned CrVI.

Do equivalent processes / materials exist for conductive plating Al i.e., what is Alodine 5200.

Kind regards

Robert Hills
nics - Christchurch, New Zealand

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2004

When did the EU ban hexavalent chromium? Why didn't they tell us? I am sure we are still part of the European Union in the UK. Oh my God, we will have to recall all of our products, especially the ones with Alodine, chromated epoxy primers, hexavalent chromium accelerated sealants, hard chrome plating, chromic acid anodising, dichromate sealed parts, etc.

I think somehow, you have been misled. Hexavalent chromium has not been banned in Europe, although some nations have very strict controls both in their use and their application.

Disposal of hexavalent chromium products is being tightened up. There have been strict occupational exposure limits in place for a number of years throughout the European Union.

You must take care that you check your information source before making statements that will make any person involved in the surface treatment industry panic.

Also not banned in Europe - Trichloroethylene, MEK / methyl ethyl ketone, Methylene chloride, Cadmium, etc.

Anyway, back to your question. Alodine contains hexavalent chromium and is a surface conversion treatment (also generically known as "Chromate conversion coating or CCC"). If the European Union does ban hexavalent chromium then all CCCs would be affected by any ban.

Brian Terry
- Yeovil, Somerset, UK

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Hi, Robert. Things have changed quite a bit in the five years since your posting, and most suppliers of chromate conversion chemistry now offer trivalent chromium conversion coatings. But chromium plating, as opposed to chromate conversion coating, puts metallic chrome on the parts, and metallic chrome is neither trivalent nor hexavalent, it's zero valent.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 20, 2009