Hexavalent chromates 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 paint
• Conductive
• Thin
• Flexible
• Lubricious
• Easily applied
• Stable for weeks or months
• Durable
• 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 the area.
• 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 alternative.

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 adults.

In our 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

All of 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 products including:

• 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.

Some finishes that Burbank Plating Service provides are not compliant with these new standards. Cadmium plating of course is restricted. Our alternative to cadmium plating, Tin-Zinc alloy plating outperforms cadmium in almost everyway. Tin-Zinc plating is the perfect alternative to cadmium and with the addition of trivalent chromate, it has none of the restricted substances.

Burbank 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.

Call Burbank Plating Service Corp for more information and pricing.