the big deal about hexavalent chromium, a.k.a. Chrome 6 (CrVI)?
How to make sure your parts are EVL and RoHS Compliant
have been in use for the purpose of passivating zinc and cadmium
plating for over 100 years. Hexavalent based chromates possess
many favorable characteristics in addition to increasing the
corrosion prevention performance of plated parts.
- Prevents Oxide Formation
- Provides Color
- Slows corrosion
- Provides adhesion for organics such as
- Easily applied
- Stable for weeks or months
- Resilient (repairs itself)
When the surface of a part is damaged, hexavalent chromates
have a unique self-healing property, which means that if
scratched the chrome layer will flow back and repassivate
- Coats in recesses
- Easy to strip
Never the less, the push to replace chromates
that use hexavalent chromium is gaining momentum. Hexavalent
chromium is considered a hazardous substance (toxic and carcinogenic).
There is a growing need to provide an environmentally friendly
However, not all forms of chromium are hazardous
to humans. Trivalent Chromium (CrIII) is actually an essential
nutrient that aids the body to use sugars, proteins and fat.
An intake of 50 to 200 µg per day is recommended for
ongoing effort to provide state of the art plating finishes,
Burbank Plating Service has developed
chromating systems that use the trivalent form (CrIII) of
chromium. This eliminates hexavalent chrome from the finished
part. We are the only metal finisher, this side of the Mississippi
that has been approved to provide the new General Motors,
Ford and Daimler Chrysler’s Trivalent Zinc plating specification.
GMW3044 and Ford S-437 and Daimler Chrysler PS-79
the pressure to eliminate CrVI has originated in the European
Union. First was the ELV that stands for the End of Life Vehicle
Directive May 23, 2000. Contained in the directive is a mandate
that no more than 2 grams of Chrome VI be present per vehicle.
When the car is disposed of or recycled they are concerned
that the chrome will end up in the environment.
One European automaker conducted a detailed vehicle teardown
and determined that less than 1 gram of hexavalent chromium
was present on its vehicles presently.
The RoHS Directive (The Restriction of Hazardous
Substances) was the next to come from the E.U. This directive
was created to define the design phase restricting the use
of hazardous materials. This directive put forth by the European
Union states that from July 1, 2006 new electrical and electronic
equipment put on the market will not contain lead, mercury,
cadmium, hexavalent chromium, polybrominated biphenyls (PBB)
or polybrominated diphenyl ethers (PBDE).
The RoHS Directive applies to most electronic
- Large household appliances
- Small household appliances
- IT and telecommunication equipment
- Consumer electronics (televisions video
players, hi-fi equipment)
- Lighting equipment
- Electrical and electronic tools
- Toys, leisure and sports equipment (video
games and train sets)
- Medical Equipment systems
Next was the WEEE directive that addresses
the disposal, recycling and reuse at the end of a products
life phase. (Waste of Electrical and Electronic Equipment).
If your products contain any of the banned substances, then
the final distributor must finance and instigate a recycling
program and clearly instruct the consumer not to throw the
product in the trash. This directive applies to all 25 current
EU Member States. Canada, China and Japan have adopted similar
laws to reduce pollution.
that Burbank Plating Service
provides are not compliant with these new standards. Cadmium
plating of course is restricted. Our alternatives to cadmium
plating are Zinc Nickel and Tin-Zinc Alloy which outperforms cadmium in almost
everyway. Tin-Zinc plating and Zinc Nickel are the perfect alternatives to cadmium and with the addition
of trivalent chromate, they contain none of the restricted substances
Plating Service provides these new trivalent chromates
on zinc plating. This finish on zinc provides a bluish clear
shinny appearance, similar to the old blue zinc, and can perform
just as well or better than the traditional hexavalent chromates.
The addition of a sealer topcoat, which is recommended in
most cases, is a requirement to meet the automotive specifications.
Non-Hexavalent black chromate is also available. The use of
our trivalent chromating systems insure compliance with the
EVL, RoHS and WEEE Directives.
Burbank Plating Service Corp
for more information and pricing.