Calcium hypochlorite, an inorganic compound with the chemical formula Ca(ClO)2, is often used in the bleaching process in chemical production. It plays an important role in industrial production due to its rapid onset and outstanding bleaching effect.

Chemical formula: Ca(ClO)2
Molecular weight: 142.983
CAS Number: 7778-54-3
EINECS Number: 231-908-7

Safety description: S26; S36/37/39; S45; S61

Hazard symbol: C

Hazard descriptions: R8; R22; R31; R34; R50

Melting point: 100℃
Density: 2.35g/cm3
logP: 1.242
Refractive index: 1.545
Appearance: white powder
Solubility: soluble in water, insoluble in ethanol

Strong oxidants, water or humid air can cause combustion and explosion, and mixing with alkaline substances can cause explosions. Exposure to organic matter may cause a fire hazard, and heat, acid or sunlight will decompose to release irritating chlorine gas.

Hydrophobic parameter calculation reference value (XlogP): none
Number of hydrogen bond donors: 0
Number of hydrogen bond acceptors: 2
Number of rotatable chemical bonds: 0
Number of tautomers: 0
Topological molecular polar surface area: 46.1
Number of heavy atoms: 5
Surface charge: 0
Complexity: 2
Number of isotope atoms: 0
Determine the number of atomic stereocenters: 0
Uncertain number of atomic stereocenters: 0
Determine the number of bond stereocenters: 0
Uncertain number of bond stereocenters: 0
Number of covalent bond units: 3

Mainly used in the bleaching of pulp in the paper industry and the bleaching of cotton, hemp and silk fabrics in the textile industry. It is also used for sterilization and disinfection of urban and rural drinking water, swimming pool water, etc. The chemical industry is used for the purification of acetylene, the manufacture of chloroform and other organic chemical raw materials. It can be used as anti-shrinking agent and deodorant for wool.

Bleaching powder, English name is Calcium hypochlorite, Chinese alias is calcium hypochlorite, CAS number is 7778-54-3, molecular formula is Ca(ClO)2, white powder, with a smell similar to chlorine gas, used for cotton, linen, paper pulp , Bleaching of silk fiber fabrics, sterilization and disinfection of drinking water, swimming pool water, etc., purification of acetylene, etc.

safety term
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
After eye contact, rinse immediately with plenty of water and seek medical advice.
S36/37/39: Wear suitable protective clothing, gloves and eye/face protection.
Wear appropriate protective clothing, gloves and eye/face protection.
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the lable where possible).
In the event of an accident or if you feel unwell, seek medical advice immediately (show the label if possible).
S61: Avoid release to the environment. Refer to special instructions/Safety data sheets.
Avoid release into the environment, refer to special instructions/safety receipt leaflet.
Dangerous Terms
R8: Contact with combustible material may cause fire.
Contact with combustible materials may cause a fire.
R22: Harmful if swallowed.
It is harmful if swallowed.
R31: Contact with acids liberates toxic gas.
Contact with acids releases toxic gases.
R34: Causes burns.
Cause burns.
R50: Very toxic to aquatic organisms.
Very toxic to aquatic life.

Hazard overview
Health hazards: The dust of this product is irritating to the conjunctiva and respiratory tract, and can cause tooth damage. Skin contact can cause moderate to severe skin damage.
Explosion hazard: This product supports combustion and is irritating.
first-aid
Skin Contact: Immediately remove contaminated clothing and rinse skin thoroughly with soap and water. seek medical attention.
Eye Contact: Lift the eyelids and flush with running water or normal saline. seek medical attention.
Inhalation: Quickly leave the scene to fresh air. Keep the airway open. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. seek medical attention.
Ingestion: Drink enough warm water to induce vomiting. seek medical attention.
Fire-fighting measures
Hazardous combustion products: chlorides, calcium oxide.
Fire fighting methods: Firefighters must wear gas masks and full-body firefighting suits to put out the fire in the upwind direction.
Extinguishing media: direct water, mist water, sand.
Emergency release treatment
Emergency treatment: isolate the leaked contaminated area and restrict access. It is recommended that emergency personnel wear dust masks (full face masks) and protective clothing. Do not come into direct contact with spillage. Do not allow spillage to come into contact with reducing agents, organics, flammables or metal powders.
Small spills: Avoid raising dust, collect with a clean shovel in a dry, clean, covered container, and transfer to a safe place.
Large spills: Cover with plastic sheeting, canvas. Then collect for recycling or transport to waste disposal sites for disposal.
Handling and Storage
Operation precautions: closed operation, strengthen ventilation. Operators must undergo special training and strictly abide by operating procedures. It is recommended that the operator wear a hood-type electric air-supplied filter dust respirator, a tape gas protective clothing, and neoprene gloves. Keep away from fire and heat sources, and smoking is strictly prohibited in the workplace. Keep away from flammable and combustible materials. Avoid generating dust. Avoid contact with reducing agents and acids. When handling, it should be lightly loaded and unloaded to prevent damage to packaging and containers. Vibration, impact and friction are prohibited. Equipped with the corresponding variety and quantity of fire fighting equipment and leakage emergency treatment equipment. Empty containers may be harmful residues.
Storage Precautions: Store in a cool, ventilated warehouse. Keep away from fire and heat sources. The storage temperature should not exceed 30℃, and the relative humidity should not exceed 80%. The packaging is required to be sealed and not in contact with the air. It should be stored separately from reducing agents, acids, combustibles, etc., and should not be mixed. It should not be stored in large quantities or stored for a long time. Storage areas should be provided with suitable materials to contain spills.

Part 1 Chemicals and Enterprise Identification

Chemical Chinese name: bleaching powder

Chemical common name or trade name: bleaching powder

Chemical English name: calium hypochlorate; Bleaching Powder

Chemical formula: CaCl₂·Ca(OCl)₂·2H₂O

Chemical molecular weight: 290.02

National emergency number:

SECTION II INGREDIENTS / COMPOSITION INFORMATION

Ingredients: (chlorine salt mixture) see table

No. Ingredient Molecular formula Index (%) Remarks

Superior product First-class product Qualified product

1 Calcium chloride CaCl₂ ≤60.0 ≤61.0 ≤62.0 Most components

2 Calcium hypochlorite Ca(OCl) 2 ≥35.0 ≥32.0 ≥28.0 Active ingredient

3 Water H₂O ≤4.0 ≤5.0 ≤7.0 Reaction

4 Calcium chlorate Ca(ClO)₃ ≤0.7 ≤1.35 ≤2.0 Chemical reaction

Element

5 Calcium hydroxide Ca(OH) 2 ≤0.2 ≤0.5 ≤0.8

6 Basic calcium chloride Ca(OH)Cl ≤0.09 ≤0.13 ≤0.17

7 Other impurities / ≤0.01 ≤0.02 ≤0.03 Mechanical wear

Chemical name: bleaching powder

Hazardous components: calcium hypochlorite [Ca(OCl)₂]

Concentration: 28%—35%

C A S No. 7778-54-3

PART III RISK OVERVIEW

Hazard Class: Oxidizing, Corrosive

Dangerous features: 1. Violent decomposition at high temperature may cause explosion.

2. Contact with water or humid air will cause combustion and explosion.

3. In case of acid or dilute acid, it will cause combustion and explosion.

4. In case of metal powder, the danger is increased or there is a danger of combustion and explosion.

5. In case of grease, it will cause combustion and explosion.

6. Corrosive.

7. It has a special irritating smell.

Routes of entry: Inhalation, ingestion, skin contact.

Health Hazard: The dust of this product is irritating to the cornea and respiratory tract, and can cause tooth damage. Skin contact can cause skin damage, and wet skin contact can cause moderate to severe skin damage.

Environmental Hazards: It has the property of hydrochloride (chlorine salt).

Explosion Danger: This product supports combustion and is irritating.

Part IV First Aid Measures

Skin Contact: Immediately remove contaminated clothing and rinse skin thoroughly with soap and water. seek medical attention

Eye Contact: Lift eyelids and flush with running water or saline. seek medical attention.

Inhalation: Get out of the scene quickly to fresh air. Keep the airway open, if breathing is difficult, give oxygen, if breathing stops, perform artificial respiration immediately. seek medical attention.

Ingestion: Drink enough warm water to induce vomiting. seek medical attention.

Part 5 Fire-fighting measures

Hazardous Properties: Strong oxidizing agent. Contact with water or humid air will cause a fire and explosion. Mixing with alkaline substances may cause an explosion. Contact with organic matter may cause a fire hazard. Heat, acid or sunlight will decompose and release highly toxic chlorine and oxygen.

Hazardous combustion products: chlorides, calcium oxide.

Fire fighting method: Wear a gas mask and full-body fire-fighting suit, and put out the fire in the upwind direction.

Extinguishing agent: direct water, mist water, sand.

Precautions for Fire Extinguishing: Do not use chemical agents and organic or acidic chemicals to extinguish fire.

PART VI ACCIDENTAL RELEASE MEASURES

Emergency treatment: 1. Isolate the leakage pollution area and restrict access.

2. Emergency personnel are recommended to wear dust masks (full face masks) or self-contained breathing apparatus, and wear protective clothing. Do not come into direct contact with spillage.

3. Completely separate the leakage from reducing agents, organics, flammables, or metal powders

4. Small amount of leakage, avoid dust, collect it in a dry, clean, covered container with a clean shovel, and transfer it to a safe place.

5. A large amount of leakage should be covered with plastic sheeting and canvas to reduce scattering. Then collect for recycling or transport to waste disposal sites for disposal.

Elimination method: Collect and recycle or transport to waste disposal site for disposal.

Part VII Handling and Storage

Operation precautions: closed operation, strengthen ventilation. Operators must undergo special training and strictly abide by operating procedures. Operators should wear dust masks, neoprene gloves, protective clothing, and water shoes. It is recommended that the operator wear a hood-type electric air-supplied filter dust respirator, a tape gas protective clothing, and neoprene gloves. and other labor protection equipment. Keep away from fire and heat sources. Smoking is strictly prohibited in the workplace with good ventilation. Keep away from flammable and combustible materials. Avoid generating dust. Avoid contact with reducing agents and acids. When handling, it should be lightly loaded and unloaded to prevent damage to packaging and containers. Vibration, impact and friction are prohibited. Equipped with the corresponding variety and quantity of fire-fighting equipment and leakage emergency treatment equipment and corresponding items. Empty containers may be harmful residues.

Storage Precautions: Store in a cool, ventilated warehouse. Keep away from fire and heat sources. The storage temperature should not exceed 30℃, and the relative humidity should not exceed 80%. The packaging is required to be sealed and not in contact with the air. It should be stored separately from reducing agents, acids, combustibles, etc., and should not be mixed. It should not be stored in large quantities or stored for a long time. Storage areas should be provided with suitable materials to contain spills.

SECTION VIII EXPOSURE CONTROLS/PERSONAL PROTECTION

Occupational exposure limit: no data available

China MAC (mg/m3): no standard

Former Soviet Union MAC (mg/m3): no standard

TLVTN: No information available

TLVWN: No data available

Maximum allowable concentration: no data available

Monitoring method: rapid colorimetric tube method for water quality (made in Japan, hypochlorite)

Engineering control: The production process is closed and ventilation is strengthened. Safety showers and eye wash facilities are provided.

Respiratory protection: Wear a dust mask when you may be exposed to dust. It is recommended to wear a hood-type powered air-filtering dust respirator.

Eye protection: Wear dust goggles and masks when you may come into contact with dust. It is recommended to wear a hood-type powered air-filtering dust respirator.

Body protection: Wear a hat, a protective tape gown, and water shoes.

Hand Protection: Wear neoprene gloves.

Other protection: Smoking, eating and drinking are prohibited on the work site. After work, take a shower. Practice good hygiene. Part IX Physical and Chemical Properties

Main ingredient: bleaching powder industry standard (HG/T 2496-2006)

Available chlorine content: 35.0% for first-class products, 32.0% for first-class products, 28.0% for qualified products

Appearance and Properties: White powder with strong chlorine odor. Its solution is yellow-green translucent liquid.

pH value: meaningless

Melting point (℃): 100℃ (decomposition)

Boiling point (℃): No information available

Relative density (water=1): 2.35

Relative vapor density (air=1): 6.9

Saturated vapor pressure (kPa): no information available

Heat of combustion (kJ/mol): meaningless

Critical temperature (°C): meaningless

Critical pressure (MPa): meaningless

Logarithmic octanol/water partition coefficient: no data available

Flash point (℃): meaningless

Ignition temperature (℃): meaningless

Upper explosion limit % (V/V): meaningless

Lower explosion limit % (V/V): meaningless

Solubility: soluble in water, milky white

Main uses: disinfectants, insecticides, fungicides, bleaching agents, etc.

Other physical and chemical properties: After calcium hypochlorite is completely decomposed to release oxygen, it has the property of hydrochloride (chlorine salt).

Section 10 Stability and Reactivity

Stability: Stable.

Incompatible substances: reducing agents, acids, alkalis, ammonia, flammable or combustible substances, water.

Conditions to Avoid: Humidity, hot air.

Polymerization Hazard: No information available

Decomposition product: Highly toxic chlorine gas (≥400.0℃) is released at high temperature, and oxygen is released at normal temperature. The product after complete decomposition is hydrochloride (chlorine-containing salt).

Combustion (decomposition) products: chloride, calcium oxide.

Section 11 Disposal

Waste Properties: Hydrochloride (chlorine salt).

Disposal methods: Refer to national and relevant regulations before disposal. Dispose of in safe burial.

Disposal precautions: It is harmful to the environment, and special attention should be paid to water bodies.

SECTION 12 TRANSPORT INFORMATION

Dangerous Goods Number: 51043

UN number: 1748

Packaging Marks: 9, (27)

Packing category: 052

Packaging method: The first-class products of bleaching powder must be packed in iron drums lined with plastic bags (the thickness of the barrel should not be less than 0.5MM), the plastic bags should be sealed, and then tightly covered with an iron cover embedded with a rubber ring. Hoop tightly, other grades of bleaching powder use iron drums, cardboard drums, wooden boxes (the thickness of the board is not less than 12MM) or woven bags, all lined with plastic bags, the sealing must be tight, and the net weight is 10, 25, 30, 40, 50 , 100kg.

Transportation Precautions: It is shipped separately during transportation. Make sure that the packaging bag does not leak, fall or be damaged during transportation. When transporting, the transport vehicle shall be equipped with fire-fighting equipment of the corresponding variety and quantity. It is strictly forbidden to mix and transport with acids, flammables, organics, reducing agents, spontaneous combustion items, wet flammable items, etc. During transportation, the speed of the vehicle should not be too fast, and no forcible overtaking is allowed. Before and after loading and unloading of the transport vehicle, it should be thoroughly cleaned and washed, and it is strictly forbidden to mix impurities such as organic matter and inflammable matter.

Section 13 Regulatory Information

Regulatory Information: Regulations on the Safety Management of Chemical Hazardous Substances (issued by the State Council on February 17, 1987)

Detailed Rules for the Implementation of the Regulations on the Safety Management of Chemical Hazardous Substances (Hua Lao Fa [1992] No. 677)

Regulations on the Safe Use of Chemicals in the Workplace ([1996] Ministry of Labor No. 423)

Other regulations: Classification and marking of commonly used hazardous chemicals (GB13690-92) This substance is classified as Class 5.1 oxidant

Safety technical regulations for the production of bleaching powder and bleaching solution (HGA007-83)

Scope of preparation of chemical safety technical instructions (GB16483-2000)

People’s Republic of China Chemical Industry Standard (Bleaching Powder) (HG/T 2496-93)

Section 14 Additional Information

Reference: “Bleaching Powder” HG/T 2496—93

“General Rules for the Storage of Commonly Used Chemical Dangerous Goods” GB 15603-1995

“Regulations on the preparation of chemical safety labels” GB 15258-1999

“Regulations on the Compilation of Chemical Safety Data Sheets” GB 16483-2000

“Packaging, Storage and Transportation Graphical Marks” GB 191-2000

“Dangerous Goods Packaging Marks” GB 190-90

“Regulations on the Compilation of Chemical Safety Data Sheets” (GB16483-2000)

“Classification and Marking of Commonly Used Hazardous Chemicals” GB13690-92

Additional Information: “Concise Chemistry Booklet”

[College Entrance Examination Center]

Active ingredient of bleaching powder: Ca(ClO)₂

Main components: CaCl₂, Ca(ClO)₂

Bleaching principle: Ca(ClO)₂+H₂O+CO₂=CaCO₃+2HClO;

NaClO+HCl (dilute)+NaOH+H₂’+Cl₂’

Purification of water

In rural areas, people often drink river water, and the river water often contains a large amount of impurities such as sediment, suspended solids and bacteria. Generally, chloric acid can be used to kill bacteria. Dissolving bleaching powder (the main component is calcium hypochlorite) in water can generate calcium chloride and hypochlorous acid. The following are the steps for the treatment of drinking water:

River water → adding alum → precipitation → filtering → adding bleaching powder → purified water

The preparation method of calcium hypochlorite includes:

Chlorine gas is passed into the calcium hydroxide solution. At high concentration, Ca(ClO)2·2CaCl2 can be crystallized, which is widely used in bleached paper:
2 Ca(OH)2 + 2 Cl2 → Ca(ClO)2 + CaCl2 + 2 H2O
Or chlorine gas is passed into the mixed solution of calcium hydroxide and sodium hydroxide:
Ca(OH)2 + 2 Cl2 + 2 NaOH → Ca(ClO)2 + 2 H2O + 2 NaCl

Calcium hypochlorite is not very soluble in water. Its stability is inversely proportional to water content, the decomposition reaction is strongly exothermic, and the products are calcium chloride and dichlorine monoxide. Calcium hypochlorite reacts with carbon dioxide to form calcium carbonate, releasing chlorine gas:

2Ca(ClO)2 + 2CO2 → 2CaCO3 + 2Cl2 + O2
Reacts with hydrochloric acid to form calcium chloride:

Ca(ClO)2 + 4 HCl → CaCl2 + 2 H2O + 2 Cl2
Calcium hypochlorite hydrolysis ionic equation: ClO-+H2O→HClO+OH-(reversible)