Chlorine was discovered in 1774 and named in 1810. It is a yellow-green gas that is heavier than air and has a pungent odor. Chlorine is widely used for water purification and in household cleaning products. Exposure to chlorine can irritate the skin, eyes, and respiratory system, and cause coughing, chest pain, and fluid in the lungs. If exposed, quickly leave the area, remove clothing, and wash the entire body with soap and water. Seek medical help immediately.

1. At a Glance

2. Discovered in 1774 by Carl Wilhelm Scheele, who mistakenly
thought it contained oxygen. Chlorine was given its name in 1810 by
Humphry Davy, who insisted that it was in fact an element. The
name chlorine is derived from chloros, meaning green, referring to
the color of the gas.
Chlorine in Periodic Table
Symbol: Cl Atomic number: 17
Electron configuration: [Ne] 3s23p5 Electronegativity: 3.16
Boiling point: -34.04 °C Atomic mass: 35.453 ± 0.002 u
Chlorine gas can be recognized by its pungent, irritating odor,
which is like the odor of bleach. The strong smell may provide
adequate warning to people that they are exposed.
INTRODUCTION

3. Chlorine (Cl2) is among the ten highest volume chemicals
manufactured in the United States. It is produced commercially by
electrolysis of sodium chloride brine. Chlorine is used in industry
and in household cleaning products. Chlorine was also the first
poison gas to be used as a weapon during World War I.
Chlorine is a yellow-green gas at room temperature.
Chlorine has a pungent, irritating odor similar to bleach that is
detectable at low concentrations.
The density of chlorine gas is approximately 2.5 times greater than
air, which will cause it to initially remain near the ground in areas
with little air movement.
Chlorine is not flammable, but may react explosively or form
explosive compounds with many common substances.
Chlorine is slightly water soluble, and reacts with moisture to form
hypochlorous acid (HClO) and hydrochloric acid (HCl).
Chlorine is commonly pressurized and cooled for storage and
shipment as an amber-colored liquid.
MORE ABOUT CHLORINE

4.  Chlorine is an important chemical in water purification,
in disinfectants, in bleach and in mustard gas.
 Chlorine is also used widely in the manufacture of many products
and items directly or indirectly, i.e. in paper product production,
antiseptic, dyestuffs, food, insecticides, paints, petroleum
products, plastics, medicines, textiles, solvents, and many other
consumer products.
 It is used to kill bacteria and other microbes from drinking water
supplies.
 Chlorine is involved in beaching wood pulp for paper making,
bleach is also used industrially to remove ink from recycle paper.
 Chlorine often imparts many desired properties in an organic
compound when it is substituted for hydrogen (synthetic rubber),
so it is widely use in organic chemistry, in the production of
chlorates, chloroform, carbon tetrachloride, and in
the bromine extraction.
APPLICATIONS

5. Chlorine dissolves when mixed with water. It can also escape
from water and enter air under certain conditions. Most direct
releases of chlorine to the environment are to air and to surface
water.
Once in air or in water, chlorine reacts with other chemicals. It
combines with inorganic material in water to form chloride salts,
and with organic material in water to form chlorinated organic
chemicals.
Because of its reactivity chlorine is not likely to move through the
ground and enter groundwater.
Plants and animals are not likely to store chlorine. However,
laboratory studies show that repeat exposure to chlorine in air
can affect the immune system, the blood, the heart, and the
respiratory system of animals.
Chlorine causes environmental harm at low levels. Chlorine is
especially harmful to organisms living in water and in soil.
ENVIRONMENTAL EFFECTS OF CHLORINE

6.  Chlorine is a highly reactive gas. It is a naturally occurring element.
The largest users of chlorine are companies that make ethylene
dichloride and other chlorinated solvents, polyvinyl chloride (PVC)
resins, chlorofluorocarbons, and propylene oxide. Paper companies
use chlorine to bleach paper. Water and wastewater treatment
plants use chlorine to reduce water levels of microrganisms that can
spread disease to humans (disinfection).
 Exposure to chlorine can occur in the workplace or in the
environment following releases to air, water, or land. People who use
laundry bleach and swimming pool chemicals containing chlorine
products are usually not exposed to chlorine itself. Chlorine is
generally found only in industrial settings.
 Chlorine enters the body breathed in with contaminated air or when
consumed with contaminated food or water. It does not remain in
the body, due to its reactivity.
HEALTH EFFECTS OF CHLORINE

7.  Effects of chlorine on human health depend on how the amount of
chlorine that is present, and the length and frequency of exposure.
Effects also depend on the health of a person or condition of the
environment when exposure occurs.
 Breathing small amounts of chlorine for short periods of time
adversely affects the human respiratory system. Effects differ from
coughing and chest pain, to water retention in the lungs. Chlorine
irritates the skin, the eyes, and the respiratory system. These
effects are not likely to occur at levels of chlorine that are normally
found in the environment.
 Human health effects associated with breathing or otherwise
consuming small amounts of chlorine over long periods of time are
not known. Some studies show that workers develop adverse effects
from repeat inhalation exposure to chlorine, but others will not.
HEALTH EFFECTS OF CHLORINE C O N T I N U E . .

8.  People’s risk for exposure depends on how close they are to the
place where the chlorine was released.
 If chlorine gas is released into the air, people may be exposed
through skin contact or eye contact. They also may be exposed by
breathing air that contains chlorine.
 If chlorine liquid is released into water, people may be exposed by
touching or drinking water that contains chlorine.
 If chlorine liquid comes into contact with food, people may be
exposed by eating the contaminated food.
 Chlorine gas is heavier than air, so it would settle in low -lying
areas.
HOW CAN PEOPLE BE EXPOSED TO CHLORINE

9. The health effects resulting from
most chlorine exposures begin within
seconds to minutes. The severity of the
signs and symptoms caused by chlorine
will vary according to amount, route and
duration of exposure.
 Inhalation: Most chlorine exposures
occur via inhalation. Low level exposures
to chlorine in air will cause
eye/skin/airway irritation, sore throat
and cough. Chlorine's odor provides
adequate early warning of its presence,
but also causes olfactory fatigue or
adaptation, reducing awareness of one's
prolonged exposure at low
concentrations
IMMEDIATE SYMPTOMS OF
CHLORINE EXPOSURE

10.  Ingestion: Since chlorine is a gas at
room temperature, it is unlikely that a
severe exposure will result from
ingestion. However, ingestion of chlorine
dissolved in water (e.g., sodium
hypochlorite or household bleach) will
cause corrosive tissue damage of the
gastrointestinal tract.
 Eye/Dermal Contact: Low level
exposures to chlorine gas will cause eye
and skin irritation. Higher exposures may
result in severe chemical burns or
ulcerations. Exposure to compressed
liquid chlorine may cause frostbite of
the skin and eyes
IMMEDIATE SYMPTOMS OF
CHLORINE EXPOSURE C O N T I N U E . .

11.  During or immediately after exposure to
dangerous concentrations of chlorine, the
following signs and symptoms may develop:
 Blurred vision
 Burning pain, redness, and blisters on the skin if
exposed to gas. Skin injuries similar to frostbite can
occur if it is exposed to liquid chlorine
 Burning sensation in the nose, throat, and eyes
 Coughing and Chest tightness
 Fluid in the lungs (pulmonary edema) that may be
delayed for a few hours
 Nausea and vomiting
 Watery eyes
 Showing these signs or symptoms does not
necessarily mean that a person has been
exposed to chlorine.
IMMEDIATE SYMPTOMS OF
CHLORINE EXPOSURE C O N T I N U E . .

12.  Leave the area where the chlorine was
released and get to fresh air. Quickly
moving to an area where fresh air is
available is highly effective in reducing
exposure to chlorine.
 If the chlorine release was outdoors, move away
from the area where the chlorine was released.
Go to the highest ground possible, because
chlorine is heavier than air and will sink to low-
lying areas.
 If the chlorine release was indoors, get out of
the building.
 If you think you may have been exposed,
remove your clothing, rapidly wash your
entire body with soap and water, and get
medical care as quickly as possible.
HOW PEOPLE CAN PROTECT THEMSELVES

13.  Removing and disposing of clothing:
 Quickly take off clothing that has liquid chlorine on
it. Any clothing that has to be pulled over the head
should be cut off the body instead of pulled over the
head. If possible, seal the clothing in a plastic bag.
Then seal the first plastic bag in a second plastic
bag. Removing and sealing the clothing in this way
will help protect you and other people from any
chemicals that might be on your clothes.
 If you placed your clothes in plastic bags, inform
either the local or state health department or
emergency personnel upon their arrival. Do not
handle the plastic bags.
 If you are helping other people remove their
clothing, try to avoid touching any contaminated
areas, and remove the clothing as quickly as
possible.
HOW PEOPLE CAN PROTECT THEMSELVES
C O N T I N U E …

14.  Washing the body:
 As quickly as possible, wash your entire body with
large amounts of soap and water. Washing with
soap and water will help protect people from any
chemicals on their bodies.
 If your eyes are burning or your vision is blurred,
rinse your eyes with plain water for 10 to 15
minutes. If you wear contacts, remove them before
rinsing your eyes, and place them in the bags with
the contaminated clothing. Do not put the contacts
back in your eyes. If you wear eyeglasses, wash
them with soap and water. You can put the
eyeglasses back on after you wash them.
 If you have swallowed (ingested) chlorine, do
not induce vomiting or drink fluids.
 Seek medical attention right away. Consider
dialing 911 and explaining what has
happened
HOW PEOPLE CAN PROTECT THEMSELVES
C O N T I N U E …