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About 30 percent of the 126 toxic pollutants listed by
the U.S. Environmental Protection Agency (EPA) may be found in printing
and publishing operations.
Organic pollutants include substances like benzene,
carbon tetrachloride, and isopropyl alcohol. Metals of concern are
known as "heavy metals," and they include lead, mercury, silver, and
chromium.
Many inks contain heavy metals, which are used to give
the pigments color and substance. Silver is a by- product of
photo-processing; fortunately, it can be recovered from spent fixing
solutions before it enters the waste stream. Toxic organics are
components of pressroom chemical compounds such as press washes. Some
are being phased out of use thanks to their replacement by non-toxic
substitutes.
"Air emissions from the offset lithographic printing
process are primarily generated from inks, fountain solutions, cleaning
solvents, and adhesives applied during folding. Emissions from printing
ink consist of ink oil in both the particulate and the vapor state. The
fountain solution, cleaning solvents, and adhesives typically contain
volatile organic compounds, or VOCs, which can evaporate in the
pressroom atmosphere during printing or discharge from a drying-oven
air stack." VOCs are thought to be key ingredients of urban smog.
The federal government's 1990 Clean Air Act Amendments
requires all major sources of air pollutants to obtain operating
permits and adhere to a variety of reporting and pollution-control
compliance requirements. A printing plant can be considered a major
source of pollution if it has the potential to emit at least 10 tons of
VOCs per year and is located in an "ozone non-attainment area" as
defined by the EPA.
Basically, this means that most large printing plants in
urban areas--especially those in the Maine-to- Virginia region--will be
subject to air permit requirements.
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