Hazards of Materials

Only available on StudyMode
  • Download(s) : 90
  • Published : February 5, 2013
Open Document
Text Preview
A fire occurred in a transformer vault that supplied power to a pesticide storage warehouse. The warehouse also caught fire. The warehouse was located in a rural area. There was a river adjacent to the warehouse that was the source of drinking water for a town downstream of the warehouse.

The chemical products that were used in the transformer and the chemicals that were stored in the warehouse were all industrial strength and were supposed to be handled with extreme caution. All of these chemicals are either combustible and were themselves, and/or release very hazardous by-products. The by-products of this blaze were immediately dangerous to firefighters that try to stop the fire and are dangerous to the people of the town via airborne chemicals from the fire and chemicals in the water runoff that has contaminated the water supply. These chemicals included; polychlorinated biphenyl, pyridine, 2,4,5-T, and parathion.

PCB

The first chemical to be effected by the fire is the PCB (polychlorinated biphenyl). This chemical is used as an electro conductor in the transformer and cools the transformer. PCB contains hydrogen, carbon and chlorine.

This chemical can cause skin irritation and redness of skin in its original form if skin contact does occur. The LD50 for PCB is 8500 – 11,900 ppm. Exposure to PCB can cause defatting and chlorance. Both of these are from coming in direct contact with the chemical to your skin. These conditions have been known to cause infections and also sometimes become chronic. Infections can lead to death but this chemical, in small amounts is not known to lead to death.

PCB becomes more dangerous in the short term when it decomposes. Decomposition of PCB is caused by heat. When PCB decomposes, the products are much more immediately dangerous. These products include; Hydrochloric acid, Phenolics, and Aldehyde. Hydrochloric acid can be immediately dangerous to life an health, the IDLH is 50ppm. Phenolics or Carbolic acid can burn skin and lungs if it comes into contact with either. Carbolic acid will ignite at 715 degrees Celsius and become either carbon monoxide or carbon dioxide or both. Aldehydes are more dangerous than the other products of decomposition. Aldehydes are a class of compounds (including formaldehyde) that are extremely flammable and toxic if inhaled. The IDLH is only 20 ppm, the short term effect level is 2.5 ppm and the long term effect level is 1.2 ppm. Ignition for aldehydes happens at around 170 degrees celcius and produces little dangerous products of combustion.

The environmental effects of spilled PCB are costly to clean up and have a large environmental impact. The half life of PCB’s range from 2.5 – 5 years. PCB’s have a specific gravity of 1.5 which means that they will sink in water and become stagnant in the bottom on the body of water. When PCB’s enter the water they will stay there for years and cleanup requires millions of dollars and expensive equipment to be done. When cleanup occours, it is not certain that all of the PCB’s will be cleaned up and will still pose a threat to some ecosystems. PCB’s have been known to be in plant tissue, which gets eaten by fish, which get eaten by people. PCB’s in people are known carcinogens. High enough levels of PCB’s in people are also known to cause skeletal deformations and mental disabilities to new babies. PCB’s in females can mimic estrogen and cause breast, cervical and uterus cancer.

The bi-products of the decomposition of PCB have much shorter half lives but they are still dangerous to the environment. Hydrochloric acid can make the stream acidic and kill any wildlife in the surrounding area. The Phenols are also an acid, increasing the acidity of the water. The most dangerous bi-products are the aldehydes. These chemicals are extremely water soluble and are very toxic to people and fish in even small amounts. If the Aldehydes found their way into the drinking water, people would get very sick and...
tracking img