strict governmental regulations resulting from the Clean Air Act Amendment
(CAA) of 1990 are impacting the surface finishing industry.
Platers and chemical suppliers are under intense pressure to minimize,
and often eliminate, potentially hazardous substances from manufacturing
operations. Accordingly, both the Environment Protection Agency (EPA)
and Occupational Safety and Health Administration (OSHA) have been
empowered by the federal government to enforce such regulations.
While much has been written on the regulations pertaining to chromium,
the average person is often left a bit overwhelmed with lists, acronyms,
acceptable levels, ad infinitum. We will attempt to summarize these
regulations and offer opinions and insight on their potential affect
on the metal finishing industry. Note that this is simply a summary
and perspective. Detailed reports and regulations are available through
individual state EPA and OSHA organizations.
Hexavalent chromium, which is used in both decorative and hard coat
plating, is a confirmed human carcinogen as defined by the United
EPA, the International Agency for Research on Cancer, and the National
Toxicology Program. Simply stated, sufficient evidence exists linking
exposure to hexavalent chromium with cancer in people, not just laboratory
animals. In hexavalent chromium plating operations, the plating solution
is agitated with air and heated. Chromium plating tanks employ ventilation
systems to remove moisture, fumes, and heat from the workspace.
Consequently, chromium is carried in the moisture as an aerosol
and is discharged into the atmosphere both inside and outside the
workspace. Thus, there is risk of human exposure within the work area
and potential atmospheric pollution by airborne hexavalent chromium.
Trivalent chromium, which is used for decorative plating, is regulated
the CAA. Less is known about the cancer risk from trivalent chromium,
but it is capable of accumulating in the lungs, thereby decreasing
function. However, independent research bodies and the regulatory
agencies have deemed it safer than hexavalent chromium for humans
and the environment. Thus, it is not as heavily regulated as hexavalent
The United States' EPA regulates air emissions through the CAA.
The Superfund Amendments and Reauthorization Act (SARA) of 1986,
Title III, a community right-to-know regulation, established a list
chemicals considered hazardous air pollutants (HAPs) subject to
regulation. These HAPs are summarized in the accompanying table,
along with the maximum allowable limits considering cost, energy
requirements, and environmental impact.
The United States Department of Labor, through OSHA, regulates
workplace exposure. Workplace regulations are designed to protect
the health and safety of workers for an average eight hour day, 40
week, over a working lifetime. The permissible exposure level in the
workplace to hexavalent chromium is 0.1 mg/m3 as CrO3 (ceiling)
per eight hour day.
The EPA regulates discharge to water. Chromium and its compounds
are listed as hazardous substances and toxic pollutants under the
Clean Water Act. Note that many regulations and requirements will
by individual states to satisfy the requirements. Individual state
authorities should be contacted.