
CHEMICAL DATA NOTEBOOK SERIES #40 Titanium Tetrachloride
HAZARDOUS MATERIALS
TITANRIM tetrachloride is a corrosive, water-reactive, toxic, irritating, colorless, fuming liquid with an acrid, choking odor, it is used in the manufacture of titanium metal, pigments, other titanium compounds, and catalysts for polymerization. Titanium metal is very valuable because of its lightness and strength, while titanium pigments are very valuable to the paint and plastics industries. Titanium dioxide is the most widely used white pigment where “whiteness” and opacity are required. Its chemical formula is TiCl4.
PROPERTIES
Titanium tetrachloride is a nonflammable liquid, but some references say it will burn in oxygen. It is a stable chemical but reacts violently with many other chemicals. It has a specific gravity of 1.73, a vapor density of 5.54, and a molecular weight of 189.7. It boils at 278°F, freezes at -9.8°F, and is soluble in cold water. It reacts violently with hot water and reacts with moisture in the air no matter what the temperature. Some references say titanium tetrachloride reacts violently with water at any temperature, so exercise care whenever the chance exists that it may be in the presence of water.
HAZARDS
Titanium tetrachloride is corrosive to bodily tissues in both its liquid and vapor phases and is highly corrosive to metals if moisture is present. The product’s reaction with water creates hydrochloric acid and titanium hydroxide and liberates heat in the process. Although the presence of an acid (hydrochloric) and a base (titanium hydroxide) may lead one to expect a classic neutralization reaction, this is not the case in this situation. The hydrochloric acid is generated as hydrogen chloride, a gas that leaves the reaction and forms hydrochloric acid when it dissolves in the moisture in the air, while the titanium hydroxide stays in solution with the water that caused the reaction.
The hydrochloric acid formed is highly corrosive to bodily tissues and metals and causes severe damage to any machinery exposed to the reaction. When contact with metal occurs, hydrogen gas evolves. Hydrogen gas is very flammable and highly explosive. It burns with an extremely hot (and sometimes barely visible) flame. Reactions of titanium tetrachloride with metals in the presence of moisture must be treated like the reaction of a strong acid on metal or bodily tissues, even though titanium tetrachloride is not an acid.
Because this material tends to react with water to liberate hazardous byproducts, it must be manufactured, used, and stored in a moisture-free environment. Any water that gets into or even near the exposed product begins the acid-forming reaction.
A person directly exposed to titanium tetrachloride in liquid or vapor form will sustain severe burns and tissue damage. Eye contact also results in severe and permanent damage.
Ingestion of the liquid causes severe burns of the mouth, tongue, esophagus, and stomach. Abdominal pain, coughing, cramps, edema, nausea, nervous depression, vomiting, spasms, and diarrhea may also occur. Ingestion in large quantities causes death.
Inhalation of titanium tetrachloride vapors causes irritation and corrosive damage to the nose, throat, bronchial tubes, and lungs. Inhalation of small amounts causes coughing, dizziness, and headaches, while inhalation of greater amounts results in lung damage, bronchial pneumonia, and death.
The TLV-TWA is 0.5mg/m3 (milligrams per cubic meter) or 0.4 ppm (parts per million of air). From 50 to 100 ppm are tolerable for one hour, while 1,000 ppm to 2,000 ppm are very dangerous, even in a very brief exposure.
Although titanium tetrachloride is considered a stable chemical, it reacts with a large number of other chemicals, sometimes violently. In addition to water, it reacts most violently with explosives, causing the explosive material to detonate. It also reacts with active metals, alcohols, epoxides, peroxides, and many other materials.
NONFIRE RELEASE
Titanium tetrachloride is shipped and stored as a liquid. In any release, the product is in the liquid form unless, of course, the ambient temperature is below the freezing point of the product. The liquid begins to fume as soon as it comes in contact with air. The titanium tetrachloride vapors and the gaseous hydrogen chloride formed by the reaction with moisture in the air are both heavier than air—the vapors of titanium tetrachloride are more than six-and-ahalf times heavier than air, while the specific gravity of hydrogen chloride is 1.26.
SYNONYMS
anhydrous titanium tetrachloride
tannic chloride
“tickle”
titanic chloride
titanium chloride
titanium (IV) chloride
IDENTIFICATION NUMBERS AND RATINGS
CAS
(Chemical Abstract Services)
7550-45-0
STCC
(Standard Transportation Commodity Code)
4932385
RTFXS
(Registry of Toxic Effects of Chemical Substances)
XR1925000
UN/NA
(United Nations/North America)
1838
CHRIS
(Chemical Hazard Response Information System)
ITT
DOT
(U.S. Department of Transportation)
Corrosive
NFPA
3-0-1
IMO
(International Maritime Organization)
8.0, corrosive
Both materials (vapor and gas) sink to the ground and flow along low spots in the terrain. The hydrogen chloride seeks out moisture in which to dissolve, forming hydrochloric acid. The titanium tetrachloride vapors, being considerably more dense, travel farther and therefore spread their hazards to a greater degree. As this vapor encounters moisture, the reaction produces more and more hydrogen chloride, which spreads its hazards farther. The vapor density of titanium tetrachloride causes the much lighter (although still heavier-than-air) hydrogen chloride to travel farther downwind than expected.
Therefore, because of its fuming nature and the vapor density of the product, make all approaches from upwind and be sure to move rapidly if the wind shifts. Although titanium tetrachloride is nonflammable, there is the possibility that explosive quantities of hydrogen gas may be generated as the hydrogen chloride formed reacts with metals that it contacts. Although the danger of ignition of hydrogen is low because it is so light and therefore will disperse very rapidly, the danger could exist in enclosed space where titanium tetrachloride might come to rest because of its high vapor density.
The danger of asphyxiation from reduction of oxygen caused by the presence of the product in low-lying or enclosed areas is also possible, although the immediate danger to the human body is lung damage by breathing the titanium tetrachloride vapors. This occurs only if someone is trapped in an atmosphere saturated with the vapors of the product or hydrogen chloride gas.
In any event, these vapors are so pungent that you cannot stay voluntarily in such an atmosphere without respiratory protection. Therefore, no emergency responder should ever become involved with this product without wearing positive-pressure, self-contained breathing apparatus and proper protection for normally exposed skin.
An unexpected hazard exists for firefighting apparatus in any release involving titanium tetrachloride: The hydrochloric acid produced by the reaction between hydrogen chloride and water can damage pumps, engines, and other metallic parts of the apparatus.
GLOSSARY
Base—a chemical compound that contains the hydroxide (OH+1) ion, is the chemical opposite of an acid, and is active chemically.
Catalyst—any substance that in small quantities affects the rate of a chemical reaction without being consumed in the reaction.
MSDS—material safety data sheet. A nonuniform document that manufacturers and others must send to users of hazardous substances. By law the MSDS must contain, at a minimum, certain information describing the hazardous properties of the substance.
Neutralization—the chemical reaction of an acid with a base, bringing the solution to a pH of 7.0 (neutral). Also, the reaction of two or more chemicals that results in a neutral solution.
Polymerization—the chemical reaction in which monomers combine with themselves to form polymers.
Needless to say, make the decision to evacuate downwind as soon as possible and notify the proper environmental authorities of the release. Secure the areas of the release and take all precautions necessary for a highly corrosive atmosphere. All mitigation techniques must be geared toward the spread of both liquid and gas phases. All techniques used depend on the amount of material released, the terrain in which the spill occurred, weather conditions, threat to the population, danger to the environment, threat to systems (such as drinking water, roads, and communications), and exposure of property (including mitigation equipment).
If the container is leaking and can be repaired, take care not to allow your skin or eyes to come in contact with the product (either in liquid or vapor form) while attempting to stop the leak. Use compatible materials in patching or plugging and in protective equipment.
If you cannot repair the container, try to contain the leak. Or try to direct the liquid from the damaged container into a secure one. Sometimes you can catch liquids in an open container and pump them back into the damaged one, completing a cycle that prevents the liquid from spreading until a secure container is available. This is necessarily an open system, and fuming will occur. Again, use only compatible equipment if pumping is required.
Capture titanium tetrachloride in a containment pond by diking around the spill with soil, sand, clay, or other materials, or in a containment pit if equipment is available. Although the soil under the pond or the pit itself is contaminated by product seeping into it, containment ponds or pits limit the contamination to specific sites and allow the removal of contaminated soil on a more limited basis.
Once you contain the product, you can focus on reducing fuming. You can accomplish this by covering the area (covering a pit will be easier) with a sheet of compatible material. Blanketing with foam may be effective even though the foam is water-based and the presence of water might increase the fuming rather than decrease it. Foam may contain the fuming and might even slow its release into the atmosphere.
Once you capture the product in a pond or pit, use suction or pumping equipment to move the liquid into secure containers. All equipment and containers must be constructed from materials that will not react with or be corroded by titanium tetrachloride. Even the temporary use of equipment subject to corrosion by the product may result in an accident more severe than the original release.
After removing the product to a secure container, absorb the remainder of the material by adding more sand, soil, clay, or other absorbent material. Trained personnel must collect and remove the absorbed product and all contaminated soil caused by the liquid seeping below the ground or into the walls of the pit. They must dispose of these materials in accordance with federal, state, and local laws under the close supervision of the proper environmental authorities.
The technique of neutralization might be effective if the right materials are involved. At least one manufacturer of titanium tetrachloride says that soda ash (sodium carbonate) and baking soda (sodium bicarbonate) effectively neutralize this product. In any event, test a small sample of the released liquid by adding the neutralizers to the sample followed by a small amount of water. If no reaction (fuming) takes place, the material has been neutralized to some degree. This procedure will not only reduce the dangers caused by the formation of hydrogen chloride but will also aid in the disposal of the final, neutralized product.
Notify the proper environmental authorities as soon as possible when an incident occurs. Since the threat of fire is minimal, damage to humans and to the environment by spreading liquid or vapors is the major hazard. Therefore, consult environmental authorities throughout the incident and give their opinions serious consideration when threat to human life is replaced by threat to the environment.
Entry of titanium tetrachloride into waterways or sewers is extremely dangerous; prevent it by diverting the liquid from sewer openings, catch basins, and waterway entries. Entry into a sewer can be dangerous since water is usually present and violent reactions may occur. Since water contaminated with titanium tetrachloride may damage a sewage treatment plant, notify such facilities of location, time of entry, and the volume of material involved.
One of the mitigation techniques for handling a release of titanium tetrachloride is the use of flooding amounts of water. This causes fuming at first, but the dilution of the product stops the production of fumes. This same principle should hold true if the product enters a waterway. As the material begins to dissolve in the water, fuming should be limited to the point of entry.
Although serious generation of fumes may be small, notify all downstream users of the water immediately. The moving water contains dissolved titanium tetrachloride, hydrogen chloride, and titanium hydroxide. Depending on the concentration of these materials, serious damage could occur to any downstream user of the water.
If titanium tetrachloride does enter a waterway, direct efforts either toward damming the stream to prevent movement downstream (if feasible) or diverting the contaminated water into a lowlying holding area until trained personnel can remove the contaminated water and any soil (if necessary).
FIRE SITUATIONS
Although titanium tetrachloride does not burn under normal conditions, at least one manufacturer of the product says in its MSDS that it burns if heated to a high enough temperature.
Since titanium tetrachloride is a liquid, there is always the possibility that a sealed container holding the product may be heated and produce enough pressure to violently rupture the container. Therefore, cool all containers exposed to extreme heat by applying water with unmanned appliances from as far away as possible.
Emergency responders must consider the possibility that the cooling water might come in contact with titanium tetrachloride that unknowingly has been released. Any hydrochloric acid produced by the reaction of water with the product might attack exposed metal surfaces, generating highly flammable hydrogen. Indeed, if it is possible that any product has been released, weigh the risk of using water to cool containers against the hazard of spreading contamination through a solution of the product in water and the violent decomposition of containers.
PROTECTIVE CLOTHING AND EQUIPMENT
Any equipment or clothing used in an incident involving titanium tetrachloride must prevent skin and eye contact with the liquid, vapors, or fumes. This includes splash-proof chemical goggles; face shields; and rubber gloves, boots, and aprons. Use positive-pressure, selfcontained breathing apparatus. Also, wear total encapsulating suits if entering an area saturated with the material. Consult the manufacturers of such chemical suits. One manufacturer suggests that gloves be made from polyurethane, Saranex, or Viton.
The following is in response to readers’ letters regarding the TLV for acrylic acid as reported in my April 1989 column. It is true that the current TLV-TWA for acrylic acid is 10 ppm and 30 mg/m3. However, those values appear in parentheses and are marked by a symbol leading to a footnote that explains that the values in parentheses are to be used until an “Intended Change” takes place. The values for acrylic acid in the Notice of Intended Changes are 2 ppm and 6 mg/m3. In the “Chemical Data Notebook Series,” I use the most conservative values for all properties and regulations. While the TLV-TWA values listed for acrylic acid are not in force today, it is my opinion that they will be adopted in the next “Threshold Limit Values and Biological Exposure Indices” published by the American Conference of Governmental Industrial Hygienists. Users of acrylic acid should have taken notice of the intended change and taken the proper steps to meet the new, lower limits.
-FRANK FIRE
FIRST AID
In case of eye contact, wash with large amounts of water, occasionally lifting the lids. Do not use chemical neutralizers. Seek immediate medical treatment, particularly from an ophthalmologist.
If skin has been exposed, wipe off spilled liquid with a dry cloth and quickly flood the skin for at least 15 minutes. Direct the stream of water under clothing while removing contaminated clothing. Do not use neutralizing chemicals. Seek medical attention immediately.
For inhalation, remove the victim to fresh air and keep warm and quiet. If the victim’s breathing becomes difficult or stops, provide artificial respiration, being careful not to allow the product in the victim’s lungs or vomit to contact the first-aid giver. Maintain airway with body reclined and feet elevated. Seek medical attention immediately.
Give victim large quantities of water but do not use lavage or emesis. Do not induce vomiting but give fluids repeatedly if vomiting persists. Do not try to administer fluids to an unconscious person. Seek immediate medical help.