Polychlorinated Biphenyls (PCBs)

Polychlorinated Biphenyls (PCBs)


TOC o “1-3” h z u Abstract PAGEREF _Toc377046441 h 1Polychlorinated Biphenyls (PCBs) PAGEREF _Toc377046442 h 1CO2 – Carbon dioxide (gas) PAGEREF _Toc377046443 h 3HCL – Hydrogen chloride (gas) PAGEREF _Toc377046444 h 4HCHO – Formaldehyde (gas) PAGEREF _Toc377046445 h 4COCL2 – Phosgene PAGEREF _Toc377046446 h 5C6H5OH – Phenolic PAGEREF _Toc377046447 h 5Aldehyde (Acetaldehyde) PAGEREF _Toc377046448 h 6Dioxins (Polychlorinated dibenzodioxins) PAGEREF _Toc377046449 h 7Polychlorinated dibenzofurans PAGEREF _Toc377046450 h 7NO2- Nitrogen Dioxide or Dinitrogen Tetroxide PAGEREF _Toc377046451 h 10Insecticide Ethion PAGEREF _Toc377046452 h 10SO2- Sulfur Dioxide PAGEREF _Toc377046453 h 12Industrial Solvent Nitrobenzene PAGEREF _Toc377046454 h 12HCN – Hydrogen Cyanide PAGEREF _Toc377046455 h 14References PAGEREF _Toc377046456 h 15

AbstractThe essay is about various industrial chemicals, health effects to humans of exposure, their physical and chemical properties, their resulting products after burning or decomposing and their pollutant effects on the environment. The essay further discusses the measures that persons and firefighters should take when in contact with the fires that have some elements of the flammable chemicals and how to put out such fires with no harm.


Polychlorinated Biphenyls (PCBs)Polychlorinated Biphenyls (PCBs) are odorless and tasteless. Their shapes range from colorless oily liquids to progress viscous liquids. They darken as they get more yellow or black resins depending on the chlorine content of the PCB. It also has high thermal conductivity are very soluble in organic solvents.

The Polychlorinated Biphenyls (PCBs) have a molecular Formula of C12H10-nCln (Where n=1-10). They are steady compounds that do not decompose without extreme heat. They have a flash point of 140 degrees Celsius or higher depending on the Aroclor product level of chlorination. The PCBs are shaped by electro chlorination of biphenyl with chlorine gas, which is the method of producing hypochlorite by running an electric current over salt water. There are 209 structural isomers of PCBs also known as congeners.

The history of usage of Polychlorinated Biphenyls is that they were used as components of dielectric fluids in transformers and capacitors because of their inability to burn easily and good insulation properties. PCB was also used from 1930 to 1977 for industrial and commercial buildings, heat transfer equipment, hydraulic equipment, industrial fluids, paint, inks, plasticizers and carbonless copy paper. PCB can also be found in the food industry but the amount that is used is FDA approved. It can be found in artificial dairy products such as milk, egg and poultry.

PCBs have their Health Effects. When exposed to the epidermis for a period of time they may cause redness, dry skin and defatting based on the way that the person is handling the chemical substance. PCBs are easily absorbed through intact skin so there is a risk of getting chloracne. A skin disorder that is similar to skin spots that affect teenagers, (Rattler-Firebird, 2010). When the chemical comes into contact with your eye, it causes moderate irritation based on the way you handle the chemical substance.

If PCB is inhaled, it is produced as a vapor at elevated processing temperature. The person experiences respiratory tract irritation. Studies on animal studies show that when PCB is ingested, it can cause coughing, choking and shortening of breath. The toxicity of PCB according to LD50 is when used on rats from 2g/kg to 10g/kg in body weight. The PEL of PCB is 1mg/meter cubed. The STEL of PCB is 1mg/meter cubed. The TWA of PCB is 0.5mg/meter cubed. The IDLH of PCB is 5mg/meter cubed.

The term PCB is often used by people as a reference to chlorinated biphenyls, Aroclor, Clophen, Fenclor, Kaneclor, Pyralene, Askarel. The PCB can be decomposed in fire or hot surfaces to from gases such as CO, CO2, HCL, HCHO, COCl2, Phenolic, and Aldehyde.

The products of incomplete and complete combustion from Polychlorinated Biphenyls (PCBs)

CO – Carbon monoxide (gas)

Their exposure health effects in a short period are; changes in body temperature, changes in blood pressure, nausea, vomiting, chest pain, difficulty breathing, irregular heartbeat, headache, drowsiness, fatigue, dizziness, disorientation, hallucinations, pain in extremities, tremors, loss of coordination, hearing loss, visual disturbances, eye damage, bluish skin color, suffocation, blood disorders, convulsions and coma.

Nausea, vomiting, loss of appetite, headache, dizziness, visual disturbances, blood disorders, heart disorders, heart damage, nerve damage, reproductive effects, birth defects and brain damage are the long term exposure health effects. The toxicity Amount according to LC50 (Inhalation of Mouse) is 2444 ppm/4 hours. IDLH is 1200 ppm. The PEL is 50PPM. The STEL is 200PPM ceiling.

CO2 – Carbon dioxide (gas) Health effects of CO2 on person’s are; shortness of breath and deep breathing and that’s on an average of 2-3%. 5% will allow breathing to become heavy, profuse sweating and pulse quickening. 7.5% of CO2 in the body can cause Headaches, dizziness, restlessness, breathlessness, increased heart rate and blood pressure and visual distortion. 10% can cause impaired hearing, nausea, vomiting and loss of consciousness. 30% CO2 in the body can cause a person to go into Coma, get convulsions and finally death.

The toxicity amount according to inhalation LC50 Human is 100,000 ppm/min. IDLH is. 40,000 ppm. The PEL is 5000ppm. The STEL is 30,000 ppm.

HCL – Hydrogen chloride (gas) Severe irritation and likely burns with coughing and choking are the likely health effects when HCL is inhaled. If gasped deeply, edema and loss of the lungs may happen. Lengthy exposure may cause staining and/or corrosion of the teeth. Eye contact results to severe annoyance with likely burns, enduring visual damage and total sight damage. Skin contact with this material may cause severe irritation and tissue corrosion. Heat, flames, sparks and other foundations of HCL ignition should be avoided. Contact of water and HCL should also be avoided because they react to form a strong acid. It can also react with some metals forming combustible hydrogen gas. Hydrogen chloride can respond with cyanide creating lethal concentrations of hydrocyanic acid.

The toxicity amount according to OSHA final PEL ceiling 5 ppm or 7 mg/meter cubed, and the LD50 for HCL is used oral 700 mg/kg (Rat) or 900 mg/kg (Rabbit), the LC50 is 3124 ppm (1 hour-Rat), LD50 Dermal 5010 mg/kg (Rabbit). And IDLH is 50 ppm for Hydrogen Chloride.

HCHO – Formaldehyde (gas)Formaldehyde is dangerous and fatal if inhaled. It is also harmful in contact with the skin. When swallowed, the respiratory tract, skin, and the eyes burn resulting in allergic reactions. It is a cancer hazard when applied to humans. HCHO have a severe fire danger and therefore fire fighters should be careful when handling it. Both vapor or air mixtures of HCHO are explosive but the vapor is heavier than air. Vapors or gases could ignite at distant ignition sources and flash back and also HCHO stored in containers might rupture or explode if exposed. HCHO can be extinguished by using carbon dioxide a regular dry chemical.

The toxicity Amount according to LD50 used Orally for rats is 5628 mg/kg while 7300 mg/kg when Orally used on mice. IDLH for formaldehyde is 20 ppm based on acute inhalation toxicity data in humans. The PEL is 200 ppm TWA or 260 mg/m3 TWA. The STEL is 2 ppm.

COCL2 – Phosgene

High toxicity of phosgene, a colorless gas, saw its use as a chemical weapon during the WW1. Phosgene can cause irritation, lack of sense of smell, vomiting, chest pain, difficulties in breathing, headache, dizziness, bluish skin color, lung congestion, lung damage and finally death. For small fires containing phosgene you should use carbon dioxide, a regular dry chemical to extinguish the fire. Large fires containing phosgene should be extinguished using regular foam or flood with fine water spray

The toxicity Amount according to LC50 used for Inhalation of a rat from phosgene vapors is 334 mg/meter cubed. IDLH is 2 ppm. PEL-TWA is 0.1 ppm. The STEL is 0.06 ppm.

C6H5OH – PhenolicPhenol can cause irritation to the eyes, mucous membranes, and skin. The absorption is very quick by any route of exposure when in to contact with Phenol. It can result in severe toxicity including death. Phenol acts upon the central nervous system causing excitation and convulsions followed by sudden collapse and unconsciousness. Death can be very rapid and is due to toxic effects on the central nervous system, the heart, lungs, kidneys, and blood vessels. Ingestion quickly results in burning of the mouth, mouth sores, diarrhea, and marked abdominal pain. Inhalation can result in lung irritation and pulmonary edema. Phenol may form methemoglobin which can result in a bluish tint to the skin. Skin and eye exposure results in pain, numbness, severe burns, and eschar formation. If Phenol comes into contact with the eyes, it can cause severe corneal injury with permanent blindness.

Phenol containers can detonate violently when exposed to heat or fire. Phenol produces toxic and corrosive gases during when burning and therefore very dangerous. When dealing with a fire containing phenolic, as a firefighter you should not allow skin exposure. Do not enter a fire scene without full bunker gear such as a helmet with face shield, bunker coats, gloves, and rubber boots. Use extinguishing media such as Halon replacement, carbon dioxide extinguishers, water spray or alcohol foam for small fires. Great and dangerous fires should be extinguished with alcohol foam, water bunch, and fog. Fight fire from maximum distance just to be safe. Use water spray to cool vessels exposed to the fire. Water containing phenol can cause chemical burns to firefighters.

The toxicity Amount according to LC50 (Inhalation of rat) is 316 mg/m3 or LD50 Oral use (on-mouse) is 270mg/kg. The IDLH is 250 ppm. The PEL is 5ppm.

Aldehyde (Acetaldehyde) Aldehyde (Acetaldehyde) inhalation to units lower than 200ppm can cause nose, pharynx, and upper respiratory tract irritation with no acute lung injury. When inhaled at high concentration, it can cause inhibition of the central nervous system leading to a coma, dizziness, unconsciousness, or death. Lung edema, coughing, and difficulty in breathing lasting for a few hours to a few days are also some of the symptoms that one experiences on high aldehyde concentration.

The toxicity amount of LC50 (rat, inhalation) is 15600 mg/m3/4Hours. And LD50 is (rat, ingestion) 661 mg/kg. The STEL is 125 ppm.


Short term and long term effects of furan exposure are nausea, vomiting, headache, symptoms of drunkenness and death. Furan can also be very toxic to the lungs and damaging the nervous system as well as damaging the organs. The toxicity amount of LC50 (inhalation of a rat) is 3398 ppm/1 hour(s)

Dioxins (Polychlorinated dibenzodioxins)Dioxins can cause headache, blurred vision, nervous and respiratory system depression. When it comes into contact with the skin, it can cause chloracne. Inhalation can cause abnormalities to the enamel of the teeth, thyroid disorder and damage to the immune system. In some cases people suffer from diabetes and endometriosis.

Polychlorinated dibenzofuransThe effects of this chemical on a person are very dangerous. They can cause a lot of abnormalities. It is toxic to the environment and a pollutant. It also causes multiple types of cancers and mutagen.

Tordon* 101 Herbicide (Agent White)

Agent White is a code name for Tordon 101. Tordon 101 is a mixture of Picloram (4-Amino-3, 5, 6-trichloro-2-pyridinecarboxylic acid, and 2, 4-dichlorophenoxyacetic acid). Tordon 101 herbicide is non-volatile, cost effective and easy to use. 2, 4-Dichlorophenoxyacetic acids are incompatible with strong oxidizers, and are corrosive to metals. Tordon 101 appears an amber color with the density of 1.15 g/ml in soil or water. Picloram breaks down into naturally occurring compounds such as carbon dioxide and water. It is Insoluble in water and it easily decomposes when in water. Picloram is sensitive to continued exposure to light. Aqueous results may be decomposed by light. It is incompatible with strong oxidizing agents, strong acids, acid chlorides and acid anhydrides.

The health effect of Picloram is that when exposed to the skin for a short period of time it is essentially non-irritating to the skin. Prolonged interaction and exposure to the skin can cause slight skin irritation with local inflammation. Frequent contact could cause slight skin irritation with local redness. Picloram is unlikely to be absorbed through the skin. During a prolonged period of time, there will be no huge harmful amounts absorbed, but it causes allergic skin reactions when tested in guinea pigs. When inhaled through the mist with prolonged and excessive exposure, it may have adverse effects. If small quantities are swallowed and digested incidentally as a result of regular handling, operations are not likely to cause injury, however swallowing greater amounts can cause injury such as gastroentric distress, diarrhea, mild central nervous system depression, dysphagia, and possible transient liver and kidney injury. Eye contact causes moderate irritation and slight corneal injury. Effects of Repeated Exposure to Picloram can cause Kidney injury and damage to the liver, eyes, and the thyroid. When tested on animals there are symptoms of nausea and vomiting. There are birth defects that show on the mothers of springs in lab animals only at doses producing severe toxicity in the mother.

Agent white is used to control annoying broadleaf wildflowers and plants that tend to grow along electrical power lines, railway beds, roadsides, pipelines, and some other places. Tordon 101 is used to reduce fire hazard on military bases and around industrial manufacturing and storage sites, at the same time it does not damage grass. About 5.25 gallons of agent white were dispensed during Ranch Hand operations (War between the USA and Vietnam). More than 95 percent of Tordon 101 was applied in defoliation mission because of the persistence of Tordon 101 in Soil, it was not recommended for use on crops, but was most often used in areas where longer persistence rather than immediate defoliation was desired, such as inland forest. Tordon 101 was effective mainly on broadleaf herbaceous and woody plants. The herbicide’s action of woody plants is usually slow; however, full defoliation did not normally occur for several months.

Picloram is the active component in Tordon 101, it’s used by attaching to organic material in shallow soil layers. This limits its movement deeper into the soil though it is likely to reach groundwater or be found in surface runoff.

Unusual hazards of combustion produced in a fire are toxic and irritating hydrogen chloride or phosgene gases that can be very dangerous. Some of the extinguishing media used to put out this chemical when fighting fire is foam, dry chemical, carbon dioxide, or water spray.

The toxicity of Picloram according to the oral LD50 for Picloram is 8,200 mg/kg in rats, between 1,061-4,000 mg/kg for mice, between 1,922-3,000 mg/kg for guinea pigs. The PEL of Picloram is 15 mg/meter cubed in total dust, and 5 mg/meter cubed in respirable. The STEL of Tordon 101 is 1,250 mg/m3 or 500 ppm. TLV of Tordon 101 is 10mg/m3 and TWA is 8 hours.

Products of combustion and incomplete combustion from Tordon* 101 Herbicide (Agent White)

NO – Nitrogen monoxide

NO can cause damage to the organs such as the red and white blood cells, lungs, mucous membranes, upper respiratory tract, skin, eyes, central nervous system and also the nose or sinuses, as well as the throat.

The toxicity amount according to the LC50 (inhalation of rat) is 115 ppm/1 Hour. And IDLH is 100 ppm.

NO2- Nitrogen Dioxide or Dinitrogen TetroxideNO2 effects are mainly due to overexposure. It may irritate the mucous membranes, sinuses, pharynx, and bronchi, with pain, headache, cyanosis, irregular respiration, choking, dizziness, and possibly pulmonary edema (only after 5 hours to 72 hours of exposure time). When you inhale high concentrations of vapor, it can cause pain, choking, broncho constriction; reflex slowing of the heart, and possibly asphyxiation. Death can result from lack of oxygen.

The toxicity amount according to LC50 (Inhalation of rat) is 88 ppm/4 hours. The PEL (ceiling) is 5 ppm. The IDLH is 20 ppm.

Insecticide EthionThis is an organophosphate insecticide with a molecular formula of C9H22O4P2S4. Pure ethion is a clear yellowish liquid with an unkind sulfur-like smell. It is also a wettable emulsifiable liquid with a flashpoint of 176.1 °C. Ethion does not transpire naturally in nature. This insecticide is created commercially by shifting dibromomethane with O, O-diethyl hydrogen phosphorodithioate in ethanol under measured pH conditions. Ethion burns, but not easily ignited. Heat is used to decompose Ethion at temperatures above 302F. It emits extreme toxic fumes of oxides of sulfur and phosphorus. Acids and Alkalis hydrolyze Ethion and it is also slowly oxidized in air. Some of the extinguishing media used to sustain this burning chemical are Dry chemicals, CO2, Halon, water spray or standard foam (large fires), water spray, fog or standard foam.

Special firefighting procedures used to prevent the fire department are wearing full protective clothing and self-contained breathing apparatus. Do not breathe smoke, gases or vapors generated. Try to keep containers cool with soft stream water fog.

Usage of Ethion is in agriculture, mostly to control creatures on citrus trees. It is also used on cotton, fruit and nut trees, and some vegetables. It may also be used on lawns and turf grasses, but not used in the home for pest control. People get exposed to Ethion by working in industries that make Ethion, as pesticide applicators or eating raw fruits or vegetables that have been treated with Ethion and skin contact with soil containing Ethion.

Health effects due to Ethion exposure occurs mostly from interaction with the epidermis or breathing contaminated air. Exposure to Ethion may also happen from eating contaminated food or drinking contaminated water. Exposure to Ethion affects the function of the central nervous system and at high doses can cause nausea, sweating, diarrhea, loss of bladder control, blurring or dimness of vision, muscle tremors, and labored breathing. In rare cases when you get severe poisoning, it can result in coma, inability to breathe, and death.

The Toxicity amount according to the LD 50 values for pure Ethion in rats of 208 mg/kg. The PEL of Ethion is 0.4 mg/Meters Cubed. The STEL of Ethion is 101 mg/m³ (15 minutes) and also STEL of Ethion is 60 ppm.

The product of combustion and incomplete combustion from Insecticide Ethion

SO2- Sulfur DioxideSO2 is a colorless gas. Effects on a person exposed to Sulfur Dioxide are damaging to organs such as lungs, upper respiratory tract, skin, and eyes. When this toxic chemical is inhaled, it can be dangerous and toxic. It causes death and can cause severe irritation of the nose and the throat. When a person is exposed to this chemical at high concentrations, it can cause life-threatening accumulation of fluid in the lungs (pulmonary edema). Some of the symptoms can be coughing, shortness of breath, difficult breathing and tightness in the chest. A single exposure to a high concentration can cause a long-lasting condition like asthma and some other symptoms which may include shortness of breath, tightness in the chest and wheezing.

The toxicity amount according to LC50 (Inhalation gas in rat) is 2520 ppm/1 Hour. And the PEL is 5 ppm 8 hours and TWA 13 mg/m³ 8 hours.

Industrial Solvent NitrobenzeneA mixture of nitric acid and sulfuric acid results to nitrobenzene which is formed by benzene nitration. Nitrobenzene is a Nitro aromatic compound that exists at room temperature as an oily liquid with a strong almond like odor (Oder threshold 0.37 PPM). It is usually colorless and more of yellow or brown. Nitrobenzene can be frozen below its freezing point to form a crystal shape. Nitrobenzene has a molecular weight of 123.1g/mole and is somewhat soluble in water (water solubility is 2.090 g/L at 25 degrees Celsius), soluble in acetone, easily soluble in alcohol, benzene, oils, and ether. Nitrobenzene is a stable compound when stored below normal pressure and temperature. It can also be extremely dangerous with explosive potential when set heat or flames are close to it (ignition source is at 482°C). The flash point when closed cup is at 87.78 degrees Celsius. The melting point of this chemical is 5.7 degrees Celsius, and the boiling point is 210.8 degrees Celsius.

Molecular formula of Nitrobenzene is C6H5NO2. This chemical is produced in a repeating process by the direct nitration of benzene. Nitrobenzene has a lower explosive limit of 1.8% and upper explosive limit of 40.0%

An average of 97% of nitrobenzene is mostly used in the manufacture of aniline. It is used as a foundation and in the manufacture of benzidine, quinolone, azobenzene, rubber chemicals, pyroxylin compounds, isocya- nates, pesticides, pharmaceuticals, and dyes such as nigrosines and magenta (particularly azo dyes). We use nitrobenzene on a daily basis because it can be found in soaps, shoe and metal polishes. It is used as a solvent for cellulose ester, in modifying esterification of cellulose acetate, and in refining lubricating oils. Nitrobenzene is also used as a solvent in petroleum refining and in the synthesis of other organic compounds, such as acetaminophen.

Nitrobenzene is hazardous in some cases and its health effects may result to increase in heart rate, cause convulsions or rarely death with skin exposure. Nitrobenzene inhalation through its vapors may result in the person experiencing headaches, dizziness, nausea, fatigue, cyanosis, weakness in the body, and rarely death. Digestion can be extremely hazardous and can also cause headaches, dizziness, nausea, vomiting and gastrointestinal irritation, loss of sensation especially use in limbs and as well as causing a person to internally bleed from inside the body. This chemical is toxic , blood, kidneys, lungs, liver and mucous membranes.

The toxicity of Nitrobenzene according to the LD50 when applied orally in rats (acute) is from 350mg/kg to 780 mg/kg and dermal LD50 is 2100 mg/kg. The PEL of Nitrobenzene is 1 ppm (5 mg/meter cubed). The LTEL of Nitrobenzene is 0.2 ppm (1 mg/meter cubed). The Nitrobenzene IDLH is 200PPM based on acute inhalation toxicity data in humans.

Nitrobenzene is very flammable, and produces poisonous smokes and vapors of nitrogen oxides when heated and decomposing. When there is a fire containing nitrobenzene, you should use fine water, also liquid tight chemical protective clothing with breathing apparatus. Nitrobenzene can be very dangerous to the environment. Dermal and work related contact to nitrobenzene can occur when inhaling at workplaces or close to where nitrobenzene can be created or used. Studies show that the general population can come into contact to nitrobenzene through the breathing of ambient air. Studies show that you can come in contact with nitrobenzene by even ingesting drinking water.

The Product of incomplete and complete combustion from Industrial Solvent Nitrobenzene

HCN – Hydrogen CyanideHCN is very toxic when inhaled. The chemical can also produce significant health effects at comparatively low levels. It is also a protoplasmic poison and reduces oxygen to the tissues causing death by chemical asphyxiation. When a person is exposed to low concentrations of this gas, it can cause a person to get headaches, vertigo, irritation of the throat, difficulties in breathing, reddening of the eyes, salivation, nausea and vomiting. When affected for a long period of time with high concentration of the Hydrogen Cyanide it can cause symptoms like tachypnea, dyspnea, weakness of arms and legs, paralysis, unconsciousness, convulsions and respiratory arrest.

The toxicity amount according to LC50 (Inhalation of rat) is 140 PPM, when exposure time was 1 hour. The IDLH is 50 PPM. And the STEL absorbed through the skin is 4.7 PPM (Ceiling).


Decomposing or burning the chemicals discussed above will have harmful impacts to the environment. They will harm the environment for decades to come. Most of the products of complete combustion and incomplete combustion are very dangerous and after environment research, studies show that the environment is badly contaminated and there is a danger to both people’s health as well as the animals.

References BIBLIOGRAPHY l 1033 Rattler-Firebird. (2013). Agent Orange and Chloracne. [Online] http://rattler-firebird.org/va/agentorange/chloracne.php retrieved on 5th December 2013.