Chrome Plating Background
This page last reviewed February 15,, 2012
Chrome Plating Overview
Chrome plating is the process by which an electrical charge is applied
to a plating bath containing an electrolytic salt (chromium anhydride)
solution. The electrical charge causes the
chromium metal in the bath to fall out of solution and deposit onto
various objects (usually metallic) placed into
the plating bath.
Chrome plating operations are categorized based upon the thickness of
the chromium metal layer applied. In decorative
plating, a layer of nickel is first plated over a metal substrate.
Following this step, a thin layer of chromium
is deposited over the nickel layer to provide a decorative and
protective finish, for example, on faucets and automotive
wheels. Hard chrome plating is a process in which a thicker layer of
chromium metal is deposited directly on metal
substrates such as engine parts, industrial machinery, and tools to
provide greater protection against corrosion
and wear. Chromic acid anodizing is an electrochemical conversion
process that creates a wear and corrosion resistant
surface on metal objects but does not result in a metallic chromium
layer.
The electrical charge during the chrome plating process causes the
hexavalent chromium to be emitted from the bath
as an aerosol that, once emitted from the facility, can be inhaled and
entrained inside the lungs. In a similar
manner hexavalent chromium mist is generated during chromic acid
anodizing operations. Thus, hexavalent chromium
emissions have the potential to adversely impact public health on a
statewide basis, as well as at the local community
level.
Many chrome plating shops are small operations that have been in
business for many years and may be located in
close proximity to residences or schools. Our emission data indicate
that although statewide emissions of hexavalent
chromium have substantially decreased, people living in neighborhoods
near chrome plating shops may still be exposed
to levels of chromium that may pose health concerns. For more
information on the health effects related to exposure
to hexavalent chromium, please go to the
Toxic Air
Contaminants Staff Reports and Executive Summaries webpage.
Background Documents
Monitoring data and other information concerning hexavalent chromium.
The final report on the multi-media Chrome Plating Project is available online.
The Chrome Plating Rule Effectiveness Study Report is available online. ( PDF - 125 KB).
Chrome Plating Control Demonstration Project Staff Report, September 1989: Table of Contents and Chapters 1-4 (PDF - 1.53MB).
Control of Emissions from Chrome Electroplating and Anodizing Operations: Submitted for CAPCOA Air Pollution Control Engineering Symposium, December 1988:
Table of Contents and Chapters 1-3 (PDF - 1.9MB)
Chapter 4-6 and References (PDF- 1.5MB)
Appendices 1-3 (PDF - 1.3MB)
Technical Support Document to Proposed Airborne Toxic Control Measure for Emissions of Hexavalent Chromium from Chrome Plating and Acid Anodizing Operations: January 4, 1988
Table of Contents and Chapters 1-4 (PDF - 2.1MB)
Chapters 5-8 and References (PDF - 2.3MB)
Appendices 1-3 (PDF - 1.2MB)
Appendix 4 (PDF - 2.5MB)
Appendices 5- 8 (PDF - 2.1MB)
Please send questions or comments to: Michelle Komlenic
