Cool StuffPCBs: PolyChlorinated Biphenyls
The term PCBs is an abbreviation used for a family of chemicals called PolyChlorinated Biphenyls. There are 209 different polychlorinated biphenyls in the PCB family, with each composed of carbon, hydrogen, and chlorine in a particular pattern.
- What are PCBs?
- Are PCBs natural substances?
- How were PCBs used?
- Why were PCBs used in so many ways?
- When and why did production of PCBs stop?
- How common are PCBs in the environment?
- Do PCBs cause cancer in humans?
- Did LIPA purchase electrical equipment with PCBs?
- Does LIPA have a Letter of Explanation?
What are PCBs?
The term PCBs is an abbreviation used for a family of chemicals
called PolyChlorinated Biphenyls. There are 209 different
polychlorinated biphenyls in the PCB family, with each composed
of carbon, hydrogen, and chlorine in a particular pattern.
back to top
Are PCBs natural substances?
No. PCBs are man-made chemicals. They were produced in the
United States for about 50 years between the 1920s and the
1970s.
back to top
How were PCBs used?
PCBs were widely used in a variety of equipment and consumer
products, such as electrical transformers and capacitors,
carbonless carbon paper, paint, chlorinated rubbers, plastics,
sealants and caulking, adhesives, glues and tapes, to name just
a few.
back to top
Why were PCBs used in so many ways?
Several properties of PCBs made them valuable for many purposes.
For example, because some PCBs tend to feel slippery, they were
often used to lubricate equipment or added to lubricating
materials. In addition, PCB mixtures were ideally suited for
many electrical applications because they do not conduct
electricity easily and are not very flammable.
Also, as a result of their unique optical and physical characteristics, PCBs have been used by scientists, including cancer researchers, in fluids used to preserve samples or to view them under microscopes and by space and defense researchers in fiber optics. back to top
When and why did production of PCBs stop?
The Toxic Substances Control Act (TSCA) was passed by the
Congress in 1976. TSCA banned the manufacture and use of PCBs
for any application that was not totally enclosed because of
growing evidence of the widespread distribution of PCBs through
the environment and the related concern about possible health
and environmental risks from PCBs. back to top
How common are PCBs in the
environment?
PCBs are considered ubiquitous in the environment. What this is
that they are found at low levels nearly everywhere in the
world, even places where no PCB products were ever used, such as
the Arctic.
back to top
Do PCBs cause cancer in humans?
USEPA classifies PCBs as a probable human carcinogen based on
studies of laboratory animals and other evidence that suggests
that PCBs might cause cancer in humans.
back to top
Did LIPA purchase electrical equipment
with PCBs?
The electrical capacitors in LIPA’s service territory were
purchased with PCBs for use on both the distribution system and
certain substations. Pursuant to USEPA regulations, all
distribution system PCB capacitors were removed prior to October
1, 1988 and replaced with non-PCB capacitors. In addition,
although not required by regulations, all substation PCB
capacitors were removed in the 1990s and replaced by non-PCB
capacitors.
All LIPA distribution transformers were specified at the time of purchase from the transformer manufacturer to contain a dielectric fluid consisting of mineral oil, not PCBs. As a result, LIPA's inventory of transformers typically is expected to either contain no PCBs or low levels of PCBs (typically 0.01%). The presence of low levels of PCBs could have been caused by manufacturer processes that fabricated mineral oil transformers in close proximity to transformers manufactured to specifically contain PCBs. No analytical data is available for specific transformers. back to top
Does LIPA have a Letter of
Explanation? Print full letter
Not all transformers in the Long Island Power Authority (LIPA)
service territory belong to LIPA. For those that do, no
analytical data is available for specific transformers.
However, all distribution transformers owned by LIPA were specified at the time of purchase from the transformer manufacturer to contain a dielectric fluid consisting of mineral oil, not PCBs. As a result, LIPA’s inventory of transformers typically is expected to either contain no PCBs or low levels of PCBs (typically 0.01%).
The presence of low levels of PCBs could have been caused by manufacturer processes that fabricated mineral oil transformers in close proximity to transformers manufactured to specifically contain PCBs. back to top
