Uses of benzene

AROMATIC HYDROCARBON: USES OF BENZENE

1. USES OF BENZENE

2. Learning Targets: I can define benzene 2. I can give 3 advantages of benzene 3. I can give 3 disadvantages of benzene 4. I can explain the uses of benzene

3. BENZENE In the early days of organic chemistry, the word aromatic was used to describe fragrant substances such as benzene (from coal distillate), benzaldehyde (from cherries, peaches, and almonds), and toluene (from tolu balsam). It was soon realized, however, that substances classed as aromatic differed from most other organic compounds in their chemical behavior.

4. BENZENE Today, the association of aromaticity with fragrance has long been lost, and we now use the word aromatic to refer to the class of compounds that contain six-membered benzene-like rings with three double bonds. Many valuable compounds are aromatic in part, such as the steroidal hormone estrone and the cholesterol lowering drug atorvastatin, marketed as Lipitor. Benzene itself causes a depressed white blood cell count (leukopenia) on prolonged exposure and should not be used as a laboratory solvent.

5. BENZENE Benzene is a colorless, sweet-smelling chemical that can be derived from natural gas, crude oil, or coal. Benzene is primarily used as a feedstock, or raw material, to make other industrial chemicals, such as ethylbenzene, cumene and cyclohexane. Benzene is also used as a solvent in the chemical and pharmaceutical industries.

6. BENZENE Most benzene exposure comes from the air from a number of sources, including forest fires, auto exhaust and gasoline from fueling stations. Benzene in cigarette smoke is a major source of exposure. Very low levels of benzene have been detected in fruits, vegetables, nuts, dairy products, eggs and fish. Most people are exposed to only very tiny amounts of benzene from water and food.

7. WHAT IS BENZENE? Benzene is a chemical that is a colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable. Benzene evaporates into the air very quickly. Its vapor is heavier than air and may sink into low-lying areas. Benzene dissolves only slightly in water and will float on top of water.

8. Where benzene is found and how it is used? Benzene is formed from both natural processes and human activities. Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke. Benzene is widely used in the United States. It ranks in the top 20 chemicals for production volume. Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers. Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.

9. As a building block chemical, benzene is reacted with other chemicals to produce a variety of other chemistries, materials and, ultimately, consumer goods. Benzene is used to make other chemicals like ethylbenzene, cumene and cyclohexane, which are then reacted and used in the manufacture of a variety of materials and plastics such as polystyrene, ABS, and nylon. There can be many steps in the process that starts with the benzene molecule and ends with a completed material or consumer product. For example, benzene is a building block used to make ethylbenzene, which is then used to make styrene, which is used to make polystyrene. The end material, polystyrene, is a completely different material chemically than benzene.

10. https://www.youtube.com/watch?v=j4htxZgyQKQ

11. HEALTH EFFECT OF BENZENE Drowsiness, headaches, and dizziness have been reported when people breathed air with benzene levels of more than 10 ppm (10,000 ppbv) for a short time. Long-term exposure to benzene can increase the risk of developing leukemia. Exposure to benzene can cause anemia and weaken the immune system.

12. HEALTH EFFECT OF BENZENE  Animal studies show that inhaling benzene vapors can damage reproductive organs and cause infertility. Exposure to benzene in workplaces has caused menstrual variations. Benzene breaks down in the body to several other compounds. Those compounds can be found in the blood or urine of people who have been exposed to high levels of benzene within the past two days. Tests will prove an exposure to benzene occurred but will not predict the kind of illness that could result. We do not know what level of benzene break-down products are common in most people, since most people are regularly exposed to some amount of benzene.

13. EXPOSURE to BENZENE The most common way people are exposed to benzene is when they fill their car with gasoline. People are also exposed to benzene when they use household products that contain benzene. Benzene evaporates quickly from contaminated water. People can be exposed to benzene if they use contaminated water to bathe, shower, wash dishes or do laundry.

14. Outdoor air contains low levels of benzene from tobacco smoke, gas stations, motor vehicle exhaust, and industrial emissions. Indoor air generally contains levels of benzene higher than those in outdoor air. The benzene in indoor air comes from products that contain benzene such as glues, paints, furniture wax, and detergents. How you could be exposed to benzene

15. How you could be exposed to benzene The air around hazardous waste sites or gas stations can contain higher levels of benzene than in other areas. Benzene leaks from underground storage tanks or from hazardous waste sites containing benzene can contaminate well water. People working in industries that make or use benzene may be exposed to the highest levels of it. A major source of benzene exposure is tobacco smoke.

16. How benzene works Benzene works by causing cells not to work correctly. For example, it can cause bone marrow not to produce enough red blood cells, which can lead to anemia. Also, it can damage the immune system by changing blood levels of antibodies and causing the loss of white blood cells. The seriousness of poisoning caused by benzene depends on the amount, route, and length of time of exposure, as well as the age and preexisting medical condition of the exposed person.

17. Immediate signs and symptoms of exposure to benzene People who breathe in high levels of benzene may develop the following signs and symptoms within minutes to several hours: Drowsiness Dizziness Rapid or irregular heartbeat Headaches Tremors Confusion Unconsciousness Death (at very high levels)

18. Immediate signs and symptoms of exposure to benzene Eating foods or drinking beverages containing high levels of benzene can cause the following symptoms within minutes to several hours: Vomiting Irritation of the stomach Dizziness Sleepiness Convulsions Rapid or irregular heartbeat Death (at very high levels)

19. Long-term health effects of exposure to benzene he major effect of benzene from long-term exposure is on the blood. (Long-term exposure means exposure of a year or more.) Benzene causes harmful effects on the bone marrow and can cause a decrease in red blood cells, leading to anemia. It can also cause excessive bleeding and can affect the immune system, increasing the chance for infection.

20. Long-term health effects of exposure to benzene Some women who breathed high levels of benzene for many months had irregular menstrual periods and a decrease in the size of their ovaries. It is not known whether benzene exposure affects the developing fetus in pregnant women or fertility in men. Animal studies have shown low birth weights, delayed bone formation, and bone marrow damage when pregnant animals breathed benzene.