Bromine (Br2) [7726-95-6] is the only non-metallic element that is liquid at normal temperature and pressure. Its color is dark reddish-brown fuming liquid with strong pungent odor. Its name is derived from Greek (bromos), meaning "stink". There are two stable isotopes of bromine, 79Br and 81Br. The proportion of the two isotopes is basically equal, so its atomic weight is 79.904. Bromine has an atomic number of 35. Liquid bromine and bromine vapor are diatomic molecules (Br2) within a fairly wide range.

Bromine exposure (whether liquid contact or vapor inhalation) can cause injury, even serious injury. The liquid quickly erodes the skin and other tissues, causing irritation, burning and gangrene. Low concentration of steam can irritate eyes and respiratory tract. If exposed to dangerous concentrations, it may cause injury inflammation and edema, and then cause pneumonia. Excessive exposure to low concentrations may also cause eye and respiratory inflammation. The weighted maximum allowable exposure concentration within eight hours is 0.1 parts per million (0.1 ppm).

Bromine is an oxidant. In the United States, bromine was listed in the list of extremely dangerous substances in Chapter III, Section 302 of the Superfund Supplement and Reauthorization Act (SARA) of 1986. Bromine is subject to the reporting requirements of SARA Chapter III, Section 313 (40 CFR Part 372). The United States Environmental Protection Agency (US EPA) requires a report of 500 pounds for a spill or leakage.

The National Fire Protection Association (NFPA) rated bromine as follows:

Health-4

Flammability - 0

Reactivity - 0

Oxidant

Bromine is rated by HMIS as follows:

Health-4

Flammability - 0

Reactive physical hazard - 3

The UN number of bromine is 1744, and the rating in Regulation (EC) No1272/2008 is as follows:

Acute toxicity - Class 1

Skin corrosion-Class 1A

Acute aquatic toxicity - Class 1

General instructions

1. Carefully read and follow all instructions and warning labels.

2. Notify all personnel of potential bromine exposure hazards and provide appropriate training on first aid procedures.

3. The storage and operation of bromine should be carried out above the drip tray, which is equipped with a discharge tank and discharged into the exhaust gas recovery system.

4. The bromine operation area should have clear safety signs, and bromine operation is limited to qualified and trained personnel.

5. Keep equipment, ground, and work areas free from contamination.

If a bromine leakage accident occurs, the leaked bromine should be immediately collected and cleaned up.

a. Approved respiratory equipment and protective clothing should be worn.

b. Carefully release anhydrous ammonia vapor to neutralize bromine vapor in the air. Be careful not to overuse anhydrous ammonia.

c. Pour pure alkali solution or sea wave solution into liquid bromine for neutralization.

d. Rinse the neutralized bromine with cold water and dispose of it in a recovery tank.

e. Open doors and windows for ventilation.

7. Avoid contact between bromine and strong reducing agents, strong alkalis, metals, wood products, paper products, fibers, fats, or other combustible materials.

improve air circulation

1. Use sufficient exhaust hoods, ventilation systems, and exhaust gas absorption devices to limit the solubility of bromine vapor in the working area to within 0.1ppm. Detect the solubility of bromine in the air to ensure appropriate control is implemented.

2.The transfer or repackaging of bromine needs to be carried out in a controllable and enclosed operating environment.

3. An effective negative pressure ventilation system is required in the enclosed area for handling bromine.

Containers and Storage

1. Completely empty the transportation container.

2. Do not return used or recovered bromine or other bromine containing liquids into our containers, as this may lead to serious container malfunctions.

3. Store bromine containers in a dry, well ventilated, moisture-proof, overheat resistant, and supercooled area.

4. Only store in approved bromine containers, do not store in containers similar to food or beverage packaging.

5. Check all equipment used for bromine operation or processing for aging, and check for leaks in valves and pipe joints.

6. Protect equipment handling bromine from contact with strong alkalis, reducing agents, other metals, wood products, fibers, paper products, and fats.

Fire prevention measures

When a fire occurs that contains bromine or bromine compounds, it is necessary to wear a self-contained breathing apparatus.

2. Bromine is not a combustible substance, but it is a strong oxidant that can react violently with metals such as aluminum, titanium, mercury, sodium, and potassium.

3. Wooden products, paper products, fibers, petroleum products, plastics, and other organic compounds may burn when in contact with liquid bromine, as bromine is a strong oxidant.

4. Dry bromate (a product obtained by neutralizing bromine with sodium hydroxide) is a strong oxidizing agent and is sensitive to vibration, so special care must be taken when handling it.

In the laboratory

Bromine, commonly used in laboratories or experimental equipment, is obtained by purchasing products that are packaged in glass bottles. It can be transferred to small glass, ceramic, or lead feed containers with pistons by dumping, siphoning, or pumping.

Extensive use

A large amount of bromine transported in barrels, tankers, or international standard containerized tanks is stored in lead or lead lined steel storage tanks and transported to processes or reactions. For large storage containers, the bottom outlet cannot be used. Nickel or plastic pumps can be used to press bromine out of the container.

Because bromine can absorb moisture from the air, the storage tank should be protected against water and moisture. When bromine is exposed to normal summer air with a dew point of 5-10 ° C, it will reach equilibrium at a moisture content of approximately 70-80 ppm. Bromine with such humidity can cause severe corrosion of many metals. Dry air or nitrogen should be injected into the storage tank to maintain a slight positive pressure.

Massive storage

Fiberglass reinforced plastic (FRP) tanks or lead lined steel tanks that are properly designed according to the weight of bromine can be used. In seismic active areas, it is recommended not to use fiberglass lined storage tanks. Necessary measures must be taken to prevent freezing of bromine in storage when the temperature drops below -7 ° C. Storage tanks should be located within areas of embankments and concrete paving. To accommodate potential leaks or spills.

International standard containerized tanks

International standard containerized tanks for bromine services, with specifications ranging from 14 tons to 23 tons, can meet the specific needs of customers. The container and frame are made of steel structure, and the tank body is lined with lead or nickel plating. The containerized tank is equipped with two or three valves. The frame size of the international standard containerized tank is the standard 8'x8'x20 '. The height of the platform and valves varies depending on the international standard container capacity and design style.

Unloading of International Standard Container Tanks

The international standard containerized tank is equipped with two or three valves. In any configuration, the central valve is connected to the unloading pipeline, while the other valves are connected to the gas phase space of the international standard container. In a three valve device, one non unloading valve can be used for exhaust, while the other non unloading valve can be used to pressurize the container. Containers used outside the United States are labeled with yellow for unloading, red for exhaust, and green for pressurization. In the two valve configuration, the yellow valve is used for unloading, and the red valve is used for pressurization and exhaust of the containerized tank.

Transportation emergencies

When an emergency occurs due to a traffic accident:

1. Notify relevant emergency response departments.

2. Wear appropriate protective clothing and a self-contained breathing apparatus approved by NIOSH or equivalent institutions.

3. Isolate the accident area and evacuate those affected by the leakage accident.

4. Immediately provide first aid to the injured person and seek medical assistance.

5. Be careful when storing bromine.

6. Call NRCC or the regional suppliers listed on the safety data sheet for advice.

7. If it is necessary to discharge the bromine from the tanker, follow the advice of the Great Lakes solution personnel and transfer the bromine to another container.

8.When bromine overflows from the container, the leakage must be controlled. Controlling leaks may require specialized training or advice. Tightening loose components, plugging holes, adjusting container orientation, etc. are all techniques used to control or reduce leaks.

9. Use materials such as clay, sand, or soil to limit bromine to contaminated areas. Do not use oil spill pillows or other fiber materials to store leaked bromine, as it may increase the risk of fire.

10. Gently cover a thin layer of water on the accumulated liquid bromine to reduce the emission of bromine vapor. During the process of adding water, try not to stir the bromine solution as it will cause more steam. Covering liquid bromine with thick lime slurry can slowly neutralize bromine, thereby stopping steam emissions.

11. If the soil has absorbed bromine, pour lime water deep into the ground. When the leakage is large, excavation equipment may also be needed.

Container leakage

1.When dealing with leaked bromine cylinders, barrels, or steel cylinders, personal protective clothing, protective goggles, and self-contained breathing apparatus approved by NIOSH or equivalent organizations must be worn.

2. Evacuate unrelated personnel from contaminated areas.

3. During the entire cleaning process, a small amount of ammonia should be maintained in the atmosphere. Carefully release anhydrous ammonia into the air to neutralize bromine vapor. Be careful not to overuse anhydrous ammonia vapor. Ammonia can convert bromine into a white smoke of ammonium bromide. Do not mix liquid bromine with liquid ammonia, otherwise a violent reaction will occur. Ammonia gas (16% to 25% volume concentration) can form explosive mixtures with air.

4. Sprinkle sea wave solution, quicklime slurry, or soda ash solution on the spill. Sea waves react with bromine to produce hydrobromic acid. Solid sodium thiosulfate reacts violently with liquid bromine, so it must not be mixed.

5. Use cold water to flush the neutralized bromine into the water tank for transportation to an approved waste liquid disposal device for treatment.

6. Ventilation the area to remove ammonium bromide and bromine smoke. Clean the floor and equipment with soap and water.

Recovery and processing

1. Clean undamaged containers and store them for future inspection.

2. Transfer the remaining bromine to other containers based on the recommendations of the Great Lakes solution or its partners and/or under their supervision. Cleaning of contaminated areas

3. Spray sea wave solution, soda ash solution, or lime slurry in the contaminated area.

4. Properly scrub the area and rinse the neutralized solution with cold water into the sink for transfer to an approved waste liquid facility for treatment.