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What is Sodium Hypochlorite (Bleach)?
Sodium Hypochlorite is a greenish-yellow liquid commonly referred to as "Bleach."
The chemical formula for Sodium Hypochlorite is NaOCl.
Sodium Hypochlorite is prepared by reacting dilute caustic soda solution with liquid
or gaseous chlorine, accompanied by cooling.
Properties of Sodium Hypochlorite
Chlorine, Sodium Hydroxide (Caustic)
Sodium hypochlorite produced by a continuous process will have approximately 0.2%
by weight excess sodium hydroxide, resulting in a specific gravity of 1.160 at 120
The presence of transition metal ions (copper and nickel) is known to catalyze the
decomposition of liquid sodium hypochlorite, contributing to the loss of bleach
strength and the formation of oxygen. Loss of sodium hypochlorite strength means
more product will be needed when the bleach is used as a disinfectant.
Common Uses for Sodium Hypochorite
Sodium Hypochlorite is the main ingredient in laundry bleach. It is used extensively
as a bleaching agent in the textile, detergents, and paper and pulp industries.
It is also used as an oxidizing agent for organic products. In the petrochemical
industry, sodium hypochlorite is used in petroleum products refining. Large quantities
are also used as a disinfectant in water and wastewater treatment and sanitary equipment.
In food processing, sodium hypochlorite is used to sanitize food preparation equipment,
in fruit and vegetable processing, mushroom production, hog, beef and poultry production,
maple syrup production, and fish processing.
In various parts of the world, sodium hypochlorite strength is identified using
five common definitions that result in different numbers although the oxidizing
power is the same, i.e., the sodium hypochlorite strength is the same.
Sodium Hypochlorite Terms to Define Bleach Strength
Sodium Hypochlorite is used in varying strengths. The chart below lists some of
the varying strengths of Sodium Hypochlorite and how the variations are typically
*Note: The higher the Weight Percent of Sodium Hypochlorite, the more decomposition
of sodium hypochlorite becomes a factor. See
Decomposition of Sodium Hypochlorite for more information.
Wt. % Sodium Hypochlorite
Shock Chlorination of Wells
Household Disinfectant, Laundering Clothes, Dentistry Root Canal Treatment, Antisepsis
of Mammary Glands in Dairy Industry, Disinfectant in Hospitals, Food Processing,
Mushroom Production, Hog, Beef, and Poultry Productions, Maple Syrup Production,
Fish Processing, etc.
Disinfectant in Swimming Pools, Water Treatment, Waste Water Treatment
Sodium Hypochlorite Hazards/Precautions
Never mix Sodium Hypochlorite and Ammonia. Doing so forms a dangerous gas potentially
leading to choking and breathing difficulty.
Avoid swallowing and getting sodium hypochlorite in the eyes or on the skin.
Depending on the strength of sodium hypochlorite, severity can range from mild irritation
to severe burns.
In the event sodium hypochlorite is swallowed, seek emergency help immediately.
If the affected person is alert, give them milk or water to drink. Do
not induce vomiting. Seek immediate medical attention.
Skin or eyes should be immediatley flushed continuously and thoroughly if coming
into contact with sodium hypochlorite. Seek immediate medical attention.
In the event of inhalation of sodium hypochlorite, leave the affected area and seek
fresh air. If breathing is difficult, administer oxygen and seek immediate
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