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

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.