PCBS in Paint

It's possible. According to the Environmental Protection Agency (EPA), over 1.5 billion pounds of PCBs were produced in the U.S. before production ended in the late 1970s. Approximately 28% of these compounds were used in manufactured products such as paints and caulks. Prior to the late 1970s, PCBs were used in paints applied to land-based structures, as well as ships, in the U.S. These compounds were most frequently used as an additive for chlorinated rubber paint. PCBs were used in paints to
Reduce brittleness (i.e., act as a plasticizer),
Increase durability,
Provide chemical, water, and heat resistance, and
Serve as drying oils (resins).
Where have PCB-laden paints been found in the U.S.?
PCB-laden paints have been found on the following surfaces:
Walls, floors, stairs, handrails, and a parking garage in a government building
Boiler rooms and turbine platforms
Aircraft hangars
Swimming pools
Aquaculture tanks
A dry dock facility
Storage tanks
Ships
Railcars (in Canada)
Equipment, including extrusion presses, lathes, welders, ovens, furnaces, heat exchangers, and milling/grinding machinery
What exactly are PCBs?
PCBs, or polychlorinated biphenyls, are synthetic organic molecules that were used in products such as dielectric oils, hydraulic oils, heat-exchange oils, paints, caulks, and sealants. PCBs were popular because of their flame resistance, chemical stability, and insulating nature. The PCB molecule is comprised of two 6-carbon rings. The rings are joined via a chemical bond between two carbons, one from each ring. Chlorine atoms can be attached to any of the remaining carbons. Along the rings, 209 different chlorine arrangements, called congeners, are possible. The following figure illustrates the chemical structure of a tetrachlorinated biphenyl, with four chlorines bonded to the carbon rings.
In the U.S., PCBs were sold as different mixtures of congeners under the trade name "Arochlor." Arochlors are characterized using a 4-digit number. In most cases, the second two digits represent the percentage of chlorine atoms by weight in the mixture. As an example, Arochlor 1254, which was the most commonly used PCB mixture for paints in the U.S., contains 54% chlorine by weight. Arochlor 1254 consists of the following combination of chlorinated biphenyl compounds:
1% trichlorinated biphenyls
15% tetrachlorinated biphenyls
53% pentachlorinated biphenyls
26% hexachlorinated biphenyls
4% heptachlorinated biphenyls
1% other biphenyl compounds
Why should I be concerned about PCBs in paints?
According to the U.S. EPA:
"PCBs have been demonstrated to cause a variety of serious health effects. PCBs have been shown to cause cancer and a number of serious non-cancer health effects in animals, including effects on the immune system, reproductive system, nervous system, and endocrine system. Studies in humans provide supportive evidence for the potential carcinogenicity and non-carcinogenic effects of PCBs. The different health effects of PCBs may be interrelated, as alterations in one system may have significant implications for the other regulatory systems of the body." (http://www.epa.gov/pcb/pubs/effects.html) EPA has reported PCB concentrations in dried paint ranging from less than 1 part per million (ppm) to 97,000 ppm. PCBs can enter the human body in the following ways:
Absorption through skin by contact with dried paint
Ingestion of flaking or deteriorating paint
Inhalation of flaking or deteriorating paint Because of the potential health issues associated with PCBs, these compounds were banned by the U.S. Congress in the late 1970s.
What about caulks—do I work or live in buildings that contain PCB-laden caulks?
It's possible. In addition to use in paints, PCBs were used in some caulks until the late 1970s. PCBs made the caulk sticky and easier to apply to window frames. These PCB-laden caulks were used throughout the U.S. and the world.
In one northeastern U.S. city, caulks from 24 buildings were tested for PCBs. Of the buildings sampled, 13 had measurable levels of PCBs in caulks, and 8 had levels that were above the EPA threshold of 50 ppm for bulk PCB wastes. These buildings included the following:
A government office—35,600 ppm PCBs by mass
University student housing, a dormitory, classrooms, and offices—70.5 to 36,200 ppm PCBs by mass
An elementary, middle, and high school—5,010 to 7,740 ppm PCBs by mass
A synagogue—8,240 ppm PCBs by mass
Are PCB-laden paints and caulks an issue only in the U.S.?
No. PCB-laden paints and/or caulks have been found in countries such as Germany, Switzerland, Norway, Finland, Sweden, and Canada. PCBs were manufactured and sold outside the U.S. under the trade names Clophen (Germany), Phenoclor (France), Fenclor (Italy), and Kanechlor (Japan). Other countries where PCBs were manufactured include Austria, Czechoslovakia, USSR, the Russian Federation, Spain, and the United Kingdom. Although the manufacture and new uses of PCBs in the U.S. was banned in the late 1970s, many Western European countries did not implement a ban until the mid-1980s.