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Bleach
What Is Bleach?
Household bleaches are a part of everyday life and are in nearly
every American home, usually in more than one form. But what is
bleach?
Bleach is a very useful chemical both around the house and for
large-scale use. You can use bleach to
remove stains
on clothing or to whiten your laundry. It's used to disinfect surfaces,
too, especially in the kitchen and bathroom. You may have tried bleach
to remove mold and mildew.
Read on to learn about different types of bleach and their uses.
A Brief History of Bleach
While the word "bleach" entered the English language around the year
1050, bleach containing sodium hypochlorite was first manufactured in
the U.S. in 1913, for use as an institutional disinfectant and a water
treatment.
Before that, chemicals such as borax, ammonia and lye were the most
common bleaches in the U.S., and bleaches made using chlorine were
generally too expensive to manufacture until the 20th century.
Clorox Chemical, later called the Clorox Company, first gave samples
of bleach to consumers for household use in 1922. Since chlorine bleach
was faster and more effective than the bleaches people had been using,
it quickly became the most popular household bleach.
Today, when we say "bleach," we usually mean a chlorine bleach
solution.
Types of Bleach
There are two main classes of household bleach: chlorine bleaches and
non-chlorine bleaches (aka
oxygen bleach).
All of these bleaches are in a class of chemicals known as oxidative
agents, meaning that they cause a chemical reaction called oxidation
when they come into contact with certain stains, certain germs or other
organisms, and sometimes clothing dyes.
Chlorine Bleach for Laundry
Chlorine bleach contains the active ingredient sodium hypochlorite (NaOCl),
while non-chlorine bleaches have different active ingredients for
different purposes.
Hydrogen peroxide, for instance, is common in color-safe bleaches,
and sodium percarbonate or sodium perboate are typically used in "oxygen
power" stain removers.
So what, exactly, happens to that
ketchup stain on your white T-shirt when you bleach it? In order to
understand how chlorine bleach makes a stain "disappear," we need to
understand how colors work.
How Colors Work
Light is
both a particle and a wave; its particles, called photons, travel in
waves that have a particular length.
Not all wavelengths of light are visible to the human eye: Infrared
light wavelengths are too long for our eyes to see, and ultraviolet
wavelengths are too short. The wavelengths we can see are between 400
and 700 nanometers, and they appear as color to us.
For example, when light with a wavelength of about 475 nanometers
hits the retina in your eye, you perceive the color blue. The light that
comes from the ketchup stain on your T-shirt to your retina has a
wavelength of about 650 nanometers, which makes it appear red.
The Chemical Makeup of a Stain
The reason the ketchup stain reflects light with a wavelength of 650
nanometers has to do with its chemical makeup. Like most other
substances, ketchup is made up of multiple elements joined together by
chemical bonds to form molecules.
The electrons involved in some of these bonds are capable of
absorbing light of certain wavelengths, depending on the characteristics
of the chemical bond. The light that the electrons in a substance can't
absorb determines the substance's color.
So the ketchup stain is absorbing all of the wavelengths of normal
light that hit it — except the 650 nanometer light, which it reflects
back to your eye, making it appear red.
How Chlorine Bleach Makes Stains
'Disappear'
Many stains have a network of double bonds between carbon atoms, and
this network absorbs light. Chlorine bleach solutions can oxidize many
of these bonds, breaking them and taking away the substance's ability to
absorb light.
When this happens, the stain "disappears." When bleach oxidizes the
ketchup on your T-shirt, the ketchup stops being able to absorb light.
It then appears white, like the rest of the shirt.
The remains of the ketchup can still be there; you just won't see the
stain anymore. Soaking and washing the shirt can remove the
now-invisible stain.
Why Does Bleach Take the Color Out of
Clothes?
Since sodium hypochlorite is a powerful oxidizing agent, it is able
to oxidize chemical bonds not only in stains on your clothing, but also
in the dyes that give the clothing its color.
Anyone who has accidentally dripped chlorine bleach on their favorite
pair of jeans has experienced just how effective bleach is as an
oxidizing agent.
A non-chlorine bleach that uses a weaker oxidizing agent, such as
hydrogen peroxide, can break the chemical bonds in certain stains
without breaking the stronger chemical bonds in clothing dye.
Chlorine Bleach as a Disinfectant
The use of chlorine bleach as a medical disinfectant was first
recorded in Austria in 1847. Staff at the Vienna General Hospital began
using it to keep "childbed fever," a severe infection that killed
countless women after they gave birth, from spreading throughout the
maternity ward.
It's now used to disinfect dialysis equipment, some surgical
equipment, surfaces in hospitals and medical labs, and even some medical
waste.
The food processing industry uses chlorine bleach to kill hazardous
bacteria such as Listeria, Salmonella and E. coli
on equipment. Sodium hypochlorite also is added to municipal drinking
water to kill dangerous waterborne organisms like the bacterium Salmonella typhi, which causes typhoid fever and killed many people
before water disinfection and
antibiotic treatment became common.
Chlorine bleach kills
Vibrio cholerae, the bacterium that
causes cholera, a disease that killed in epidemic proportions before
water treatment. It can still kill in countries where clean drinking
water is not available.
Chlorine bleach can also kill dangerous bacteria and viruses on
surfaces, such as methicillin-resistant Staphylococcus aureus (MRSA),
influenza and HIV. Chlorine bleach is especially valuable as a
disinfectant, since germs are not able to develop immunity against it,
as they have done against certain drugs.
How Chlorine Bleach Kills Germs
To kill germs, sodium hypochlorite uses the same quality that makes
it such a great stain remover — its power as an oxidizing agent. When
sodium hypochlorite comes in contact with viruses, bacteria, mold or
fungi, it oxidizes molecules in the cells of the germs and kills them.
Scientists also believe that the hypochlorous acid that forms when
sodium hypochlorite is added to water can break down the cell walls of
some germs. The hypochlorous acid also seems to be able to cause certain
proteins to build up in bacteria, making their cells unable to function.
Non-chlorine bleaches that are oxidizing agents can also act as
disinfectants on some surfaces, but they are less potent than chlorine
bleach. Chlorine bleach, when used properly, is a practical and
effective disinfectant.
Additional Bleach Applications
Hospital personnel use bleach as a disinfectant, hotels use bleach to
clean and disinfect bed linens and surfaces, and restaurants disinfect
food preparation surfaces with chlorine bleach.
People use chlorine in
swimming
pools to keep the water clean and raise the pH, and in much smaller
concentrations to help keep municipal water supplies free of harmful
organisms.
Companies sometimes add chlorine bleach to industrial wastewater to
reduce odor, and chlorine is used by the glass, chemical,
pharmaceutical, textile, agriculture, paint and paper industries.
With its many uses, bleach its a very familiar product to most
people. But when did we start using this chemical?
Proper Use of Chlorine Bleach
Since chlorine bleach is a strong oxidizing agent, it's hazardous if
not used properly. You should never mix chlorine bleach with any other
household chemicals, because it can react to form very hazardous
substances.
For example, mixing bleach with ammonia or
vinegar can release poisonous chlorine gas. Cleaning and
disinfecting products that aren't called "bleach" may also contain
sodium hypochlorite as one of their active ingredients, so you should
always read the label before using a cleaning product.
How to Safely Disinfect Surfaces
If you are using bleach to disinfect household surfaces, make sure
the area is well ventilated and do not inhale any fumes. Fumes from
chlorine bleach can cause coughing, sore throat and airway irritation,
and it can also irritate the eyes.
Keep chlorine bleach from coming into contact with your skin, since
it can cause redness and irritation, especially after repeated
exposures. If bleach gets in your eyes, rinse them immediately and call
your doctor.
Ingestion of chlorine bleach can be very dangerous, especially to
children. If you or your child accidentally swallow bleach, don't induce
vomiting. Call the Poison Control Center immediately at
1-800-222-1222.
How to Safely Use Bleach for Laundry
When using chlorine bleach for laundry or cleaning, you should dilute
it.
For whitening white clothing, The Clorox Company recommends washing
the clothing on the hottest setting recommended on the fabric label and
adding 3/4 cups (177 mL) of bleach to the wash. Certain fabrics, such as
mohair, wool, silk and Spandex will be damaged by chlorine bleach, so
always read the clothing label before bleaching.
For colored garments, you can use a "bleachability test" on a
non-visible, colored part of the garment. Mix 2 teaspoons (10 mL) of
bleach with 1/4 cups (59 mL) of water, and put a drop of the solution on
a hidden part of the fabric. Wait one minute, blot with a towel and
check for any color change.
For pre-soaking a white item of clothing, you can mix 1/4 cups (59 mL)
of bleach with one gallon of water and soak for 15 minutes before
washing.
For disinfecting clothes, pre-soaking with chlorine bleach and
washing in hot water with chlorine bleach is effective, but washing with
non-chlorine bleach is not adequate, because active ingredients like
hydrogen peroxide aren't powerful enough to disinfect laundry.
For disinfecting dishes or hard surfaces, use a solution of 1
tablespoon (15 mL) of chlorine bleach mixed with 1 gallon (3.8 L) of
water.
Dos and Don'ts of Cleaning with Bleach
Don't Use It All the Time
Bleach is very strong. Reach for it to whiten laundry or
clean up body fluids like blood, vomit, or poop. It’s also a
good way to disinfect surfaces you touch a lot. That’s
things like doorknobs, countertops, or light switches.
Always cut it with water.
Don't Mix With Ammonia
This forms a toxic gas called chloramine. It can hurt the
tissue in your eyes, throat, nose, and lungs. It can also cause
breathing problems.
Don't Put Too Much in Your Laundry
Don’t pour it directly on your things. And don’t use more
than directed. That could damage them. Bleach is a good
stain remover, but you can’t use it on everything. It’s not
good for spandex, wool, silk, or leather. Always check the
label for directions on how to wash your clothes.
Don't Clean Your Phone With Bleach
Bleach can damage the screen’s fingerprint-resistant
coating. It might be OK to use an
alcohol or disinfectant wipe. Check with the company
that makes your phone to be sure. No matter what you clean
with, don’t get any moisture near the openings.
Do Protect Yourself
Bleach can burn your skin if it’s really strong. The fumes
might bother your eyes and lungs. Wearing goggles, a mask,
and gloves helps. You should also cover your
feet and wear long sleeves and pants. Remember that
bleach can stain your clothes, so don’t wear anything you
really like.
Don't Mix With Acids
Chlorine gas forms when you mix bleach with acids like
vinegar or drain cleaner. It’s dangerous to breathe in too
much of it. It might make you
cough or wheeze. Your eyes, nose, and throat may burn.
Don't Use It on Metal
Bleach is corrosive. It can eat erode, or eat away, metal
surfaces. Don’t use it on copper, stainless steel, aluminum,
or other metals. And don’t use bleach to get rid of rust,
especially on fabric. It’ll just make the stain permanent.
Do Open Windows and Doors
You should be extra careful with bleach if you have
allergies or a health condition that makes it hard to
breathe. That includes
asthma or chronic obstructive pulmonary disease (COPD).
Opening windows or doors helps air out your home. Turn on a
fan to give the fumes an extra push.
Don't Use an Old Bottle
You’ve got 24 hours to use bleach mixed with water. Pure
bleach is good for 3-5 months. Keep the bottle away from
heat and sunlight. Always toss it 1 year after it was made.
Look for a string of letters and numbers on the label. For
instance, you might see MR20106. That means it was made in
2020 on the 106th day of the year. Don’t worry about the
letters.
Don't Pour It Down the Drain
It might hurt your pipes or mix with other chemicals. Try
baking soda instead. You can toss a handful down the
drain and follow that with a rush of hot water. You can also
pour 1 cup of vinegar down the drain. Let it sit in your
pipes for 30 minutes, then run the hot water.
Do Clean With Soap and Water First
Bleach can’t power through dust and dirt. That’s partly
because a thick layer of grime protects germs. Use soap and
water to clean. Then coat the entire surface with your
bleach mix so it’s visibly wet. Let it air dry.
Don't Use It on Food
It’s OK to use bleach mixed with water on eating utensils or
surfaces like countertops. But don’t wash your fruits and
vegetables with it. Just scrub them under running water.
22 Household Bleach Uses
-
Sanitize toilet bowls. Just pour a little
bleach down the toilet each evening as you retire to bed, leave it
to work overnight, and your toilet bowls will not only remain
sparkling clean but sterilized. Don’t do this if your toilet flushes
to a septic tank, which depends on anaerobic bacteria to break down
the waste.
-
Sanitize floors. Once a week, change your usual
floor cleaner to bleach. It keeps your floors clean.
-
Remove tea and coffee stains from the inside of mugs and
cups. Add a little bleach to a basin full of water, add the
stained cups and leave to soak for a few minutes. Rinse well.
-
Add a sparkle to glasses and crystalware. Soak
in a light bleach solution for a few minutes; rinse well.
-
For cut flowers. Add a few drops of bleach to
the water in which you place cut flowers, and the water will stay
clearer for longer.
-
Kill weeds. Add undiluted bleach to weeds
growing through cracks in your walkways. It kills them and prevents
re-growth.
-
Keep swimming pool water crystal clear. Add a
five-liter drum of bleach to your swimming pool water once a month
during the winter months when your pool is not in use to keep the
water crystal clear all winter. Revert to chlorine one month before
the good weather arrives when you may wish to use your pool.
-
Whiten clothes. A little bleach added to your
washing machine whitens white clothes that have grayed.
-
Stain removal. Soaking individual items of
clothing or bedsheets in a light bleach solution can get rid of
stains.
-
Sterilize plant cuttings. Dipping plant
cuttings in a very light bleach solution sterilises them and
inhibits mold or disease growth.
-
Clean plastic garden furniture. Cleaning
plastic with a bleach solution brings out the original color while
removing stains or mildew. Great for garden furniture.
-
Get rid of mildew and mold. Mildew in bathroom
tiles can be removed by spraying with bleach, then wiping off after
a few minutes.
-
Clean shower curtains. Mildew on shower
curtains can be removed by soaking in a basin full of a bleach
solution before washing normally.
-
Disinfect garden tools. Annually soak your
garden tools in a bleach solution to keep them sanitized and reduce
the risk of spreading plant diseases.
-
Disinfect plant pots. Re-use plant pots by
washing them, then soaking them in a bleach solution to sterilize
them. Many plant diseases live on in untreated pots.
-
Kill moss and algae. Moss and algae on your
garden paths can be rid of with bleach.
-
Clean garbage bins. Plastic dustbins or
trashcans can be sterilized easily with a bleach solution, left
soaking for an hour or so.
-
Clean kitchen cloths. Kitchen cloths used for
wiping down surfaces can have a new lease of life simply by soaking
in a light bleach solution for 10 minutes or so.
-
Clean wooden chopping boards. Bleach is
fantastic for cleaning chopping boards, especially wooden ones.
Place your board over a basin in the sink and pour on straight
bleach from the bottle. Listen to it crackle and pop as it eats any
grease. You will see stains simply disappear before your eyes. Rinse
and dry well before use.
-
Make windows sparkle. A little drop of bleach
in your final water when you wash the windows will leave them
shining.
-
Disinfect second-hand toys. Anything plastic
you bring into your house that is second-hand would benefit from a
one-off sitting in a bleach solution for a few minutes to kill any
possible germs.
-
Sterilize drinking water. A few drops of bleach
added to drinking water will quickly kill any harmful bacteria that
could be lurking there, should you visit a country where the water
sanitation is less than scrupulous. 1/2 teaspoon bleach to four
gallons of water will do the trick.
Environmental Impact of Chlorine Bleach Use
The Environmental Protection Agency (EPA) has evaluated multiple
scientific studies on the effects of chlorinated drinking water, and the
organization's found no evidence of risk for
cancer, reproductive problems or birth defects.
The European Commission (EC) also determined that the most common
sources of exposure to chlorine bleach is through skin contact when
using bleach for cleaning at home or through ingestion of chlorinated
drinking water.
Swallowing small amounts of swimming pool water may also be a risk,
but there is no significant indirect exposure through the environment.
The Commission determined that there is no evidence of negative health
effects due to long-term exposure to small amounts of chlorine bleach.
According to the Centers for Disease Control's Agency for Toxic
Substances and Disease Registry, when sodium hypochlorite is released
into the air, it's broken down by sunlight and natural substances in the
environment.
Sodium hypochlorite does not accumulate in the food chain like some
substances do, such as mercury. When sodium hypochlorite gets into water
or soil, it breaks down into the ions sodium, calcium and hypochlorite;
these ions can potentially react with other substances in water, but the
possible effects are not known.
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