environmental problem associated with
nickel production is the emission of sulfur
dioxide (SO2) from smelters that process
sulfide ores. The SO2 emitted from
smelter smokestacks combines with water
in the atmosphere to form droplets of
sulftuic acid (H2SO4), a major component
of acid rain. In 1985, the Provincial
Government of Ontario ordered Inco to
reduce SO2 emissions at its Sudbury
complex from 685,000 tons per year to
no more than 265,000 tons per year.
Since then, the company has spent $530
million on state-of-the-art pollution
control equipment to meet the new limit.
The sulfur dioxide abatement project was
completed in late 1993, in time to meet
the Provincial Government's deadline of
January 1, 1994. Inco now captures
more than 90% of the sulfur in its
Sudbury ores. (See Canada section of this
report.)
The Provincial Government gave
Falconbridge a similar ultimatum.
Falconbridge had to reduce its S02
emissions from 154,000 tons per year to
100,000 tons per year by 1994. Like
Inco, the company spent millions of
dollars complying with the Provincial
order. In 1993, Falconbridge succeeded
in lowering its emission rate to 57,000
tons per year.
Recent environmental legislation and
other  responses  to  environmental
concerns are expected to significantly
affect future nickel consumption.  In
some cases, the effect will be positive; in
others, negative.
In November 1990, the Congress
amended the Clean Air Act (CAA),
updating Federal air pollution standards
for the first time since 1977 and
completely overhauling the hazardous air
pollutants program. The amendments
(Public Law 101-549), among other
things, put controls on airborne emissions
of nickel metal, its compounds, and
alloys.    Nickel  compounds  were
specifically included in the new list of
189 hazardous air pollutants to be
regulated.
The law also directed the U.S.
Environmental Protection Agency (EPA)
to develop an initial list of pollution
source  categories  that  warranted


regulation. Because of the magnitude and
complexity of the problem, it took EPA
more than 2 years to develop the list and
reply to the 140 comments received from
public and private interests. The list was
finally published in the Federal Register
on July 16, 1992.5 A number of nickel
consumers appeared on the July list,
including integrated steel mills, electric
arc furnace operations, iron and steel
foundries, and ferroalloy production
facilities.  A  draft  schedule  for
promulgating emission standards for each
of the initial 174 source categories was
published in the Federal Register on
September 24, 1992, as part of the 10-
year phase-in of CAA regulations.
Because many facilities will need new
pollution control equipment to comply
with these standards, the enactment of the
Clean Air Act Amendments is expected to
increase demand for stainless steel and
other alloys of nickel. Under the new
law, 111 fossil fuel-fired powerplants
must reduce their SO emissions by 1995.
This particular section of the law was
enacted to help control acid rain. The
111 plants-a total of 251 generating
units-were specifically targeted because
each emits more than 2.5 pounds of SO2
per million British thermal units. Some
plants will be able to reduce SO2
emissions by simply switching to fuels
that contain lower levels of sulfur; others,
though, will be forced to install scrubbers
(flue gas desulfurization units).
Because it is far cheaper and easier to
include scrubbers in the design of a new
powerplant than to retrofit an existing
facility, most plants in the near-future
will be equipped with some type of
scrubbing system. Roughly 100 tons of
corrosion-resistant alloy will be required
for each scrubber. Although it is not
clear which alloy will be used, many of
the more promising candidates contain
significant amounts of nickel, which
improves the resistance of the alloy to
corrosion and heat. A significant amount
of stainless will also go into turbines for
the new powerplants.
Toxicity.-Zero exposure to nickel is
impossible and undesirable. Studies have
shown that nickel is an essential element


in a variety of cellular organisms,
animals, and plants.6 Nickel may also be
an essential element for humans, but
more research is needed on the subject.
Some non-prescription multivitamins
contain as much as 5 micrograms of
nickel per tablet. Studies to date indicate
that inhalation is the most important route
of nickel intake in the workplace. Dermal
exposure and ingestion are also
important, but of lesser concern.
The American Conference of
Governmental  Industrial  Hygienists
(ACGIH) postponed action until 1995 on
a proposal to set more stringent
workplace limits for nickel and its
compounds. The ACGIH had proposed
reducing its recommended workplace
limits, or threshold limit values (TLV's),
for nickel metal and all nickel compounds
to 0.05 milligrams per cubic meter
(mg/m3) of air . The proposal also called
for nickel metal and all inorganic nickel
compounds to be designated "confirmed
human   carcinogens."  The   Nickel
Producers Environmental Research
Association (NiPERA), among others,
had urged the ACGIH not to reduce the
existing TLV's until new evidence, now
being gathered, could be properly
evaluated. The 8-hour TLV is currently
set at 1.0 mg/r3 for insoluble forms of
nickel (e.g., NiO) and 0.1 mg/r3 for
water-soluble forms of nickel (e.g.,
NiSO4). ACGIH guidelines are important
because the U.S. Occupational Safety and
Health Administration (OSHA) and
regulatory agencies in other countries
weigh them carefully in determining
mandatory permissible exposure limits for
the workplace.
OSHA has specified eight-hour Time
Weighted Average Permissible Exposure
Limits (PELs) for more than 400
substances, including nickel and its
compounds. In March 1993, after almost
4 years of litigation that involved reviews
by both the U.S. Eleventh Circuit Court
of Appeals and the U.S. Supreme Court,
the PEL for water-soluble nickel
compounds was set at 1.0 mg Ni/r3.
Nickel metal and insoluble nickel
compounds also have a PEL of 1.0 mg
Ni/r3. Nickel carbonyl was singled out
because of its extreme toxicity and has a


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