What are the congeners of PCBs?
A PCB congener is any single, unique well-defined chemical compound in the PCB category. The name of a congener specifies the total number of chlorine substituents , and the position of each chlorine.
What is PCB analysis?
In general, PCB methods analyze for Aroclor mixtures, PCB homologs, or individual PCB congeners. Until recently, packed column GC/ECD was used most often for the determination of PCBs as Aroclor mixtures. The Webb-McCall technique was used for quantitation.
How many PCB congeners are there?
209 distinct PCB
There are 209 distinct PCB compounds (known as congeners) with from 1 to 10 chlorine atoms on a biphenyl molecule. The number and placement of the chlorine atoms on the biphenyl molecule determines how the congener is named and dictates its environmental fate and toxicity.
Who PCB congener list?
| IUPAC Name | BZ Congener Number | CASNR |
|---|---|---|
| 2,3′,4,4′-Tetrachlorobiphenyl | 66 | 32598-10-0 |
| 2,3′,4,5-Tetrachlorobiphenyl | 67 | 73575-53-8 |
| 2,3′,4,5′-Tetrachlorobiphenyl | 68 | 73575-52-7 |
| 2,3′,4,6-Tetrachlorobiphenyl | 69 | 60233-24-1 |
What is congeners in chemistry?
Congener is a term in chemistry that refers to one of many variants or configurations of a common chemical structure. Source: GreenFacts. More: For example, polychlorinated biphenyls (PCBs) occur in 209 different forms, or congeners. Each congener has two or chlorine atoms located at specific sites on the PCB molecule.
How do you test for PCBs?
Most people have some level of PCBs in their body through food exposure, such as fish, and a blood test is best for measuring this exposure. Blood is the best thing to test in humans, opposed to fat cells, because it reflects the quantity of PCBs stored in the body, known as the body burden.
How do you calculate total PCBs?
Total PCB, calculated by multiplying the sum of the three indicator congeners by 2, showed a strong and highly significant correlation to the sum of all 209 measured congeners for each sample.
What is the normal PCB?
EPA’s enforceable MCL for PCBs in public drinking-water systems is 0.0005 ppm. FDA’s tolerance levels for PCBs in food range between 0.2 and 3 ppm.
What do congeners do?
These compounds are responsible for giving taste and aroma to the alcoholic drink. Thus, the congener amount in a drink gives it a particular taste profile. For example, acetaldehyde is an aldehyde that gives rums and bourbons a fruity smell.
How would you test PCBs and characterize suspect materials?
The sampling plan should consider the following steps:
- Test indoor air to determine if PCBs are present.
- Test suspect building material to determine PCB sources.
- Evaluate building material sample results and determine if surrounding materials warrant testing.
What is a PCB aroclor?
PCBs (commonly called Aroclors) are organic compounds with 1–10 chlorine atoms attached to biphenyl (209 distinct congeners, Figure 5). They were widely used as dielectric fluids in transformers, capacitors, and coolants.
What are symptoms of PCB?
Usually there are no immediate symptoms caused by exposure to PCBs, unless it is a massive exposure, such as falling in a tank containing PCBs or ingesting a significant amount of PCBs. In these cases, a worker may experience nausea, vomiting, respiratory irritation (sniffles, cough), and skin irritation (redness).
What level of PCBs is considered safe?
How are PCBs measured?
How do you Calculate Total PCBs? There are 209 distinct PCB compounds, known as congeners, that have between 1 and 10 chlorine atoms on a biphenyl molecule. Total PCBs can be calculated by multiplying the sum of the three indicator congeners by 2 to determine its environmental impact and toxicity.
How do congeners affect the body?
In addition, congeners may stimulate the body to release stress hormones, such as norepinephrine and epinephrine. These can cause inflammatory responses in the body that lead to fatigue and other hangover symptoms.
What is congeners in biology?
Definition of congener 1 : a member of the same taxonomic genus as another plant or animal. 2 : a person, organism, or thing resembling another in nature or action the New England private schools and their congeners west of the Alleghenies— Oliver La Farge. 3 : a chemical substance related to another.
How do you check PCB oil?
Simple test of specific gravity/density Drain a few drops of the liquid into a clean glass bottle and add a small amount of water. If the liquid sinks to the bottom, it is a PCB fluid. If the liquid is mineral oil it will float.
What is congener Aroclor 1254?
Aroclors 1016, 1242, 1254, and 1260 are complex mix- tures of polychlorinated biphenyl (PCB) congeners, prepared by the chlorination of biphenyl. For Aroclors 1242, 1254, and 1260, the chlorination reaction was stopped when the weight percent chlorine of the product had reached 42, 54, or 60%, respectively.
How many PCB homologs are there?
There are 10 possible PCB homolog groups, organized by the number of chlorine atoms in the molecule. Because of their useful electrical insulation, non-flammability and chemical stability, PCBs were used in a multitude of commercial and industrial products.
How do I get rid of PCBs?
Because PCBs accumulate in fish fat, people can reduce their intake of PCBs by removing the skin and fatty areas from fish fillets. Do not fry fish. Instead, barbecue, broil, or bake fish on an elevated rack that allows fat to drip away. You can also poach fish if you discard the broth.