Bromine
HAZARDOUS MATERIALS
CHEMICAL DATA NOTEBOOK SERIES #33
BROMINE IS AN OXIDIZING, corrosive, toxic, reactive, irritating, dark red-to-brown fuming liquid with a pungent odor. It is one of a very few liquid elements. It belongs to the family of elements known as halogens, whose other members are fluorine, chlorine, and iodine. It is used in the manufacture of dyes, fire-retardant chemicals, fumigants, bleaches, germicides, perfumes, pesticides, pharmaceuticals, water-purifiers, and many other chemicals.
PROPERTIES
Bromine is nonflammable, but as an oxidizing agent, it will support combustion. It has a specific gravity of 3.12, a molecular weight of 159.8, and a vapor density of 5.51. It boils at 137.8°F, freezes at 19°F, and is very slightly soluble in water.
Bromine has no common synonyms, but there is a chance it may be refered to as bromine solution.
HAZARDS
Bromine is very corrosive to human tissue. When dry, it will attack metals such as aluminum, potassium, sodium, mercury, tin, and titanium. When moisture is present, it will attack almost all metals. It is a very reactive chemical, and will react violently with such diverse materials as ammonia, acetaldehyde, acetylene, acrylonitrile, alkali hydroxides, calcium nitride, methanol, phosphorus oxide, and sodium carbide, among other chemicals. It is stable in contact with water, but its corrosiveness increases.
Bromine is a very powerful oxidizing agent. It is nonflammable itself, but its presence makes all normal combustible material extremely flammable, and all very flammable material explosive. Mere contact with wood, cotton, straw, or paper may cause that material to break into flame. Its very high vapor density (5.51) means that any vapors produced will hug the ground in lowlying areas, and will flow along low spots in the ground for great distances unless dispersed by a very strong wind. Bromine’s reddish-brown vapors are very noticeable in high concentrations.
The liquid’s low boiling point (137.8°F) and high vapor pressure means that any released liquid will generate large amounts of vapor. In the event of any type of release, liquid or vapor, evacuations for several hundred feet around the spill and at least a mile downwind should be considered. If the vapor should contact anything burning as it moves downwind or downhill, such combustion would be immediately intensified. The only correlation is the addition of pure oxygen to the fire.
Any apparatus caught in the vapor cloud will experience a very rapid acceleration of its engine, which will be accompanied by severe corrosion of the engine. The same is true for any internal combustion engine in any vehicle because the bromine acts as an additional oxidizer and increases the combustion of the fuel.
The chemical activity of bromine ishigh, which accounts for its violent reactivity with many materials. It is also what makes bromine so corrosive. As mentioned before, the corrosiveness of bromine increases with the presence of moisture. This hazardous property must be remembered by firefighters using water to control a fire where bromine vapors may be present. Under these conditions, bromine’s corrosiveness may damage firefighters’ equipment, including many metals and plastics.
Bromine is highly toxic by all routes of entry into the body. Its sharp and pungent odor can be detected in the range of 0.05 to 3-5 parts per million of air. Its threshold limit value-time weighted average (TLV-TWA) is 0.1 ppm, its short term exposure (STEL) limit is 0.3 ppm, and its IDLH (immediately dangerous to life and health) value is 10 ppm.
BROMINE
Inhalation of vapors, ingestion of the liquid, and any contact with the skin or eyes must be avoided. Skin contact with the liquid chemical burns, and contact of the skin with concentrated vapors produces injury with nearly the same serious results. Severe eye damage is possible from contact with high concentrations of vapors, and almost certain with contact of the liquid.
Inhalation of bromine vapors at almost any concentration will cause adverse effects, as shown by the low TLVTWA. Concentrations as low as 10 ppm (the IDLH value) may produce severe irritation of the mucous membranes and upper respiratory system and is extremely hazardous. Severe coughing spasms are caused by higher concentrations and are sometimes accompanied by dizziness, headaches, and bleeding through the nose. Severe lung problems, such as pulmonary edema and pneumonia, many follow such exposure as delayed complications. Continued exposure will cause death. The odor threshold is said to be 35 ppm, so in the case of bromine, if you can smell it, you’re in trouble.
Ingestion of bromine will cause severe burns of the mouth, throat, esophagus, and stomach that can prove to be fatal.
NON-FIRE RELEASE
Bromine may be released from its container as a liquid or a vapor. The vapor, even if leaking in an upward direction, will eventually sink to the ground because of its very high vapor density of 5.51. Unless they are being expelled from a container under extremely high pressure, the vapors will “hang together” and flow along low spots on the ground, occasionally accumulating in such low spots that might be protected from the wind. Even though the cloud may be visible, no one should enter any confined or low areas near or downwind from the leak that may not display the reddish color of the vapors. At lower but still dangerous concentrations, the vapors may not be visible.
No attempt should be made to stop the leak unless the emergency responders’ safety can be assured. Life rescue attempts, if necessary, must be conducted if the rescuer can be protected from the bromine.
If the liquid has been released, vapors will be generated as the liquid leaves the container and contacts the ground, unless ambient temperatures have created a very cold ground surface. The production of vapors is dependent upon the original temperature of the surrounding environment (including the air and ground), and the surface area of the spilled liquid. Even if the ground and air are very cold, some vapors will be produced from the liquid until it freezes at 19°F. In any event, evacuation of the spill area and areas downwind may be a necessity.
Efforts should be made to contain the liquid in containment ponds or pits. Dikes can be built around a spill using soil, sand, clay, or other materials. Containment pits may dug, and trenches may be dug to lead the liquid from the spill area to the pit. Generation of vapors may be less from pits because the exposed surface area will be less than in a containment pond. However, in cold weather, the deeper the pit is dug, the warmer the soil will be, and therefore the greater the production of vapors from the liquid.
Any equipment that might come into contact with bromine must be compatible with it. That is, it must be resistant to the oxidizing and corrosive power of bromine. Any close contact with bromine should be supervised by a qualified expert in the handling of bromine. Preplanning for a bromine release should be part of every emergency response team’s state of preparedness.
The containment of bromine (or any hazardous material) should be done under the supervision of the proper environmental agency and a qualified expert in the handling of the material. Removal and cleanup should be done by well-educated, well-trained, and well-equipped experts.
IDENTIFICATION NUMBERS AND RATINGS
BROMINE
Once the liquid is contained, it may be removed by suction into a secure container. Any remaining material may be absorbed by sand, soil, or clay, which must be removed along with any soil contaminated by contact of the liquid with the soil or percolation of the liquid into the soil. The removal of contained product and contaminated soil should be performed by trained experts under the supervision of the proper environmental authorities and disposed of under the same circumstances.
If there is a delay in removing the spilled liquid, and dangerous quantities of vapors are being generated, other mitigation techniques may be employed. Water fog or spray may be used to disperse vapors emanating from the spill. Some small amount of bromine may be dissolved in the sprayed water, so containment of this water is necessary. Consideration must be given to this extra volume of water so that the containment pond or pit is not overflowed with the runoff.
Dilution is another technique that can be used if the pond or pit is large enough. Water may be added to the bromine to slow the generation of vapors. A disadvantage is that a relatively large volume of water will be needed to dilute the bromine, which is only slightly soluble in water. However, with the high specific gravity (3.12) of bromine, it will sink below the water as it slowly dissolves.
Neutralization is another technique that may be considered. If a proper neutralization agent (as determined by an expert qualified in handling bromine) is available, it may be added to the spilled product. Small samples of the bromine and the neutralizing agent should be mixed carefully in a compatible container in a safe and secure area away from the spill as a test. The actual application of the neutralizing agent should be handled by experts called in for this procedure. At least one reference lists sodium thiosulfate solution or lime water (calcium hydroxide solution) as neutralizing agents for small spills, but again, qualified experts should be consulted before any efforts are made to neutralize bromine.
Bromine should be prevented from entering sewers and/or waterways. Sewers usually contain organic material, which will burn under ordinary conditions. Whenever an oxidizer like bromine comes into contact with such a fuel, the only leg of the Fire Triangle missing is heat (or energy). With such energy supplied in one manner or another, an underground fire in the community’s sewer system will occur. If bromine does enter a sewer, the sewage treatment facility or any other receiver of the sewer runoff must be notified’ immediately, and steps must be taken to prevent an ignition source from reaching the fuel/oxidizer mixture.
Should bromine enter a waterway, all downstream users of the water must be notified immediately. Severe damagecan be done to equipment taking in such contaminated water, and any vapors of bromine released within any confined area will be extremely dangerous to life and property.
Once bromine liquid enters a waterway, it will sink below the water and slowly begin to dissolve. If the volume of water is not large and moves slowly, the bromine may collect in deep spots in the water. Deep spots can be created by dredging or the use of sand bags. Once the bromine has collected here, it may be vacuumed out by using compatible equipment used by trained individuals. Once the bromine has been removed, environmental authorities may “require the removal of contaminated soil around the stream or contaminated material from the stream bed.
GLOSSARY
ACGIH—The American Conference of Governmental and Industrial Hygienists. It is an organization that sets limits on worker exposure to hazardous substances.
Adsorption—The adherence of one material on the surface of another. Contrast with absorption, which is the penetration of one material into the inner structure of another substance.
Aeration—The process by which air is bubbled through a liquid or the liquid is sprayed into the air.
Air-stripping—A process in which a material is pumped through an air chamber or sprayed into the open air at high pressure in order to remove contaminants.
Halogen—A member of the Group VII A elements, which are fluorine, chlorine, bromine, iodine, and astatine (very rare).
Oxidizer—Also called oxidizing agents. They are substances that contain oxygen and give it up readily or will otherwise support combustion. The halogens are oxidizers that contain no oxygen.
Sparging—A process by which air or another gas is bubbled through a liquid, solid, or gas to remove a contaminant.
STEL—Short Term Exposure Limit. It is a 15-minute time-weighted average exposure which should not be exceeded at any time during a w orkday even if the eight-hour time-weighted average is within the TLVTWA. (ACGIH)
TLV-TWA—Threshold Limit Value-Time Weighted Average. The timeweighted average concentration for a normal eight-hour workday and a 40-hour work week, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. (ACGIH)
In some cases, it may be possible to divert the contaminated waterway into a containment area where the undissolved bromine may be removed by suction. Dissolved bromine may be removed from the contaminated water by aeration, sparging, or air stripping. Caution must be used during this process because bromine vapor will be liberated from the water.
In some cases, the addition of an adsorbing agent like activated charcoal may remove dissolved bromine from the water by mixing the carbon into the water. Once the activated charcoal has been recovered from the water, the bromine is being held on the surface of the carbon particles and can be released by agitation and heat. The used activated charcoal should be treated as a hazardous material, and disposal must be done as all disposals above, in accordance with all federal, state and local regulations.
FIRE SITUATION
The release of bromine near any combustion is extremely dangerous because of the oxidation power of bromine. Any smoldering fire will likely burst into flame, and any flaming combustion will intensify greatly in the presence of bromine vapors. Therefore, all efforts should be made to keep bromine vapors from approaching a fire, or toward a situation where a fire may occur once the bromine has entered the area.
Containers of bromine exposed to flames or the radiated heat from a fire are subject to catastrophic failure due to increased pressure within the container. If a safety relief device is present and operating, bromine vapors will be released to the atmosphere. Cooling of all containers of bromine by the use of water is advised, but only if it can be delivered from a distance that provides safety to any firefighters present. The use of unmanned appliances is recommended.
It has been suggested that in the case of a gaseous oxidizing agent, a controlled burn might be an accepted mitigation technique. That is, if the oxidizer is being released and the fire is being intensified, no action may be necessary other than protection of exposures. This technique should be used only in those rare instances in which qualified experts are available to supervise the procedure, and no harm will be caused by the action.
FIRST AID
In the event of inhalation, the victim must be moved immediately to fresh air and kept quiet and warm. If breathing stops or becomes labored, artificial respiration should be administered in a manner to protect the first aid provider from the product in the victim’s lungs. Medical attention must be immediate.
For skin contact, the eyes must be flushed immediately for fifteen minutes, occasionally raising the eyelids. Again, medical attention is required immediately.
If the victim has ingested bromine, he must be made to drink large quantities of milk (or water, if milk is not available). Do not attempt to make an unconcious person drink anything. The victim must not be made to vomit, and immediate medical attention is required.
PROTECTIVE EQUIPMENT
Protective equipment and clothing should be selected that will prevent ail contact of the product with the eyes, skin, and respiratory system. This may include rubber gloves, aprons, boots, face shields, and splash-proof safety goggles.
Self-contained breathing apparatus will be required inside total encapsulating suits to prevent all contact. The total encapsulating suit must be chosen with care since bromine will attack many plastics. Resistance charts provided by manufacturers indicate the suitability of using their materials to protect against bromine.
