Electric Safety & Reliability
PCBs: 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.
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.
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.
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.
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.
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.
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.
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.
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.
