Biphenyls

__Human Health Implications__

What are the possible dangers associated with this chemical? The danger of this chemical is that it causes cancer in animals. Scientists are not sure if it can cause cancer in humans. Therefore this make the chemical a lot more dangerous because we don’t know what it can do for sure.

How, specifically, does this chemical affect the body? As of right now we know that biphenyls do have some type of negative affect on the body. The affect is usually some form a skin disease like acne. This is the only affect that we are obtusely certain about. There are other possible symptoms that scientist aren’t quite sure come from PBB. They include nausea, abdominal pain, and loss of appetite, joint pain, fatigue, and weakness.

What human body processes does this chemical affect? The body processes affected following exposure to Biphenyl include, the functioning of the nervous (cough, headache, flaccid paralysis, anorexia, nausea, vomiting or diarrhea, insomnia, depression, memory loss, facial paralysis, vertigo, numbness and aching of the extremities and fatigue) and respiratory (irritation of eyes, nose and mucous membranes, bronchitis) systems. Liver (cirrhosis and necrosis) damage has also been reported.

What human systems are affected by this chemical? The system that this chemical affects is the nervous system. This all we know for now on the systems that are affected by biphenyls.

__Synthesis/Production Section__

How is the chemical made/refined? Biphenyl is produced in generally four processes. The first process involves the hydrodealkylation of toluene (where it is a by-productin theproduction of benzene). Another method begins with the dehydrogenation of benzene (it is co-produced with terphenyl). The third process includes the fractionation and alkali extraction of mixed xylenol (where it is co-produced with o-phenylphenol). And the final method is the direct dehydrocondensation of benzene is currently used for the production of high purity biphenyl.

How are common products that contain this chemical made? Include at least 3 balanced chemical reactions related to the synthesis of the chemical and/or products. Common products containing Biphenyl include heat transferring agents and fungistats. Biphenyl is also used in the manufacture of benzidine. The former uses the vapor of Biphenyl from the liquid in chemical processes.It is also applied to the inside of shipping container or wrappers in packaging of citrus fruit. Finally, Biphenyl is the starting product that is chlorinated in a an aqueous solution (at 40 degrees centigrade over a pH range of 6.2 to 9.0 yielded o-chlorobiphenyl and mchlorobiphenyl) to frombenzidine.

__Summary__

Biphenyls are outlawed in the Untied States but people are still being exposed to them. The objects that contain biphenyls are old microscopes and fluorescent lights. Biphenyls are a good insulator that’s what they are used for. The government needs a find away to get rid of all the old objects that contain biphenyls. As as suggestion maybe they should have like a toy drive but instead it would be for old fluorescent lights and old microscopes. That might not get rid of all of it, but it sure could help. Bottom line if the government isn’t going to do anything the people should and can.

__Background__

HOW/WHY PCBs are complex mixtures of chlorinated biphenyls that vary in the degree of chlorination. [astdr] 209 individual chemical species fall under the classification of polychlorinated biphenyls. [hazardtext]

PCBs are a category of chemicals that were manufactured in the United States between about 1930 and 1977. Polychlorinated biphenyls have been commercially available since 1930; however, they are no longer commercially produced in the US. Imports of PCB's were terminated in 1980 in response to compliance with the Toxic Substances Control Act (TSCA).

Their predominant use is as coolants and lubricants in electrical equipment such as capacitors and transformers due to their general chemical inertness and heat stability.

BENEFITS/BANNING High stability contributed to the wide use of polychlorinated biphenyls as industrial chemicals prior to the EPA ban of 1977 but is also responsible for their negative long-term health and environmental effects. They are still being released into the environment from poorly maintained toxic waste sites and improper disposal. They are resistant to biodegradation and are chemically stable. [hazardtext]

PRODUCTS Pigments/inks such as dairylide yellow, benzidine yellow, phthalocyanine blues and greens (non-Cl, CP, AP approved) may contain PCBs (McMann, 1984).

MANUFACTURING Monsanto is the sole domestic manufacturer of PCB's (Sauget, IL plant). Commercial production was initiated in the United States in 1929 in response to the electrical industry's need for an improved dielectric insulating fluid for use in transformers and capacitors which would also provide increased fire resistant benefits. Domestic /USA/ production of polychlorinated biphenyls was stopped in October 1977. [hsdb]

USES • PCBs have excellent electrical insulating properties and thus found their largest application to be in electrical equipment, including electrical transformers and capacitors. They have also been used in hydraulic fluids and lubricants, gas-transmission turbines, petroleum additives, heat transfer fluids, carbonless copy paper, pesticide extenders, dedusting agents, fire retardants, and plasticizers (S Budavari, 2001; Freeman, 1989). • enzyme inducers (in research laboratories), PCB-contaminated transformer oils were reportedly being used by amateur radio operators in order to tune the frequencies of their transceivers • PCBs were/ used as heat-transfer fluids, organic diluents, lubricant inks, plasticizers, fire retardants, paint additives, sealing liquids, immersion oils, adhesives, dedusting agents, waxes, and as dielectric fluids for capacitors and transformers. • Former uses of PCB's /as of 1974/ hydraulic fluids, plasticizer in synthetic resins, adhesives, plasticizer in rubbers, heat transfer systems, wax extenders, dedusting agents, pesticide extenders, inks, lubicants, cutting oils, carbonless reproducing paper