CHEMICAL DATA NOTEBOOK SERIES #41 CHLOROFORM
HAZARDOUS MATERIALS
CHLOROFORM is a clear, colorless, volatile liquid that’s toxic, carcinogenic, anesthetic, narcotic, corrosive, and somewhat reactive. It has a pleasant, sweet, etherlike odor. Among its many industrial uses are in grain fumigation, insecticides, and animal medicine. It is used as a solvent and in the manufacture of dyes, floor polishes, pesticides, pharmaceuticals, and some plastics.
PROPERTIES
Chloroform is nonflammable and has a specific gravity of l.49, a vapor density of 4.1, and a molecular weight of 119.4. It boils at 142°F, freezes at – 82.3°F, and is slightly soluble in water. At least one reference states that chloroform burns “on prolonged exposure to flame or high temperature.” Its molecular formula is CHC13.
HAZARDS
Chloroform is a very highly used chemical, and in tests some animals subjected to high concentrations of the material over long periods of time have developed cancer. At one time chloroform was used as a human anesthetic, but that practice has been discontinued.
Chloroform is considered a stable chemical, but it reacts with a wide variety of chemicals such as acetone, disilane, nitrogen tetroxide, potassium tertbutoxidc, and sodium methylate. It also reacts with reactive metals, such as lithium, potassium, sodium, magnesium, aluminum, and pot metal. It reacts with strong caustic materials, oxidizers, halogens, halogenating chemicals, primary amines, and mixtures of some organic chemicals in basic solutions.
Although it is slightly soluble in water and does not react with water, it does react violently with a water solution of strong alkalis such as lithium hydroxide, potassium hydroxide, and sodium hydroxide. It is corrosive to iron and other metals when heated or when water is present.
Chloroform is a rather powerful anesthetic at high concentrations and can cause death through narcotic action when inhaled in such high concentrations. Other symptoms of overexposure to chloroform vapors include dilated pupils, dizziness, drowsiness, fatigue, irregular heartbeat, and nausea. Its TLVTWA (Threshold Limit Value-Time Weighted Average) is 10 ppm, its STEL (Short Term Exposure Limit) is 50 ppm for 10 minutes, and its IDLH Immediately Dangerous to Life and Health) is 1,000 ppm. Its OSHA PEL (Permissible Exposure Limit) is 50 ppm for 10 minutes. Its odor can be detected at levels ranging from 50 ppm to 300 ppm. Inhalation of the product in concentrations of 500 ppm can cause some toxic effects, and longer-term exposure causes liver and kidney damage.
Contact with the eyes can cause irritation, pain, and short-term damage to the cornea. When it comes in contact with the skin, the product dissolves fat cells, causing the skin to crack.
Ingesting chloroform burns the mouth and throat and causes chest and abdominal pains and vomiting. Ingesting the liquid in sufficient quantities damages the liver, causes unconsciousness, and can even be fatal. Liquid aspirated into the lungs can cause chemical pneumonia.
An unexpected hazard of chloroform at high temperatures is its decomposition into toxic and corrosive gases such as phosgene, carbon monoxide, chlorine, and hydrogen chloride. This decomposition takes place rather rapidly at high temperatures; the mere exposure of chloroform to air and/or light can cause the slow decomposition of the product into phosgene and carbon monoxide. The toxic effects of carbon monoxide are well-known to firefighters, while phosgene is a lesserknown but still lethal poison. Chlorine is a very poisonous gas that is also a powerful oxidizer and corrosive. It is one of the members of the halogen family—hazardous not only because of its toxicity and oxidizing powers but also because it will further react with undecomposed chloroform, causing more decomposition. Hydrogen chloride gas is an irritant that dissolves in water to form hydrochloric acid, which in turn is corrosive to most metals.
NONFIRE SITUATIONS
In the event of any release of chloroform, first responders to the incident must notify the proper environmental authorities. Throughout the incident, consult these authorities on mitigation techniques that might harm the environment. However, life safety is still the responsibility of emergency responders, who must establish and document the priority of life rescue over environmental consequences in case of repercussions after the incident. Always consider evacuation as early in the incident as possible to reduce the threat to human life. Once people are safe, environment takes precedence over property or systems damage.
With a vapor density of 4.1, chloroform’s vapors are very heavy relative to air and will travel great distances downwind in a gentle breeze. Because of its high volatility, it generates vapors rapidly and in large quantities. Thus in any release of chloroform, large quantities of vapor exist that move a long way downwind. These dense vapors accumulate in low-lying areas or confined spaces. Anyone entering such a high concentration of chloroform vapors faces an immediate danger of being anesthetized and eventually overcome to the point of asphyxiation.
If chloroform vapors pass over hot surfaces or are subjected to high temperatures, they decompose into toxic and corrosive gases. Once evacuation has been completed (if indeed it was ordered), you must monitor the potential path of the vapors for the possibility of decomposition. The hazards of the decomposition products are, in many ways, greater than the hazards of the chloroform itself.
If the container is leaking and you can catch the product in or lead it to a secure container, do so at once. The simple act of placing a leaking drum in an overpack drum might end the incident (except for cleanup).
If the container is a tank, whether stationary or on a truck or railroad car, consider patching the leak. Chloroform may attack some type of rubber or plastic used in the patching process, so select compatible materials. This information should be present on a material safety data sheet (MSDS) or the manufacturer’s specification sheet. If there is time, collect a sample of the chloroform and submerge a piece of the patching material in it. Examining the patch after five or 10 minutes can indicate its resistance to the liquid.
SYNONYMS
formyl trichloride
Freon 20
methane trichloride
methane
trichloro-
methenyl trichloride
methyl trichloride
NCI-C02686
R 20
TCM
trichloroform
trichloromethane
IDENTIFICATION NUMBERS AND RATINGS
CAS
(Chemical Abstract Services)
67-66-3
STCC
(Standard Transportation Commodity Code)
4940310 and 4940311
UN/NA
(United Nations/North America)
1888
RTECS
(Registry of Toxic Effects of Chemical Substances)
FS9100000
CHRIS
(Chemical Hazard Response Information System)
CRF
RCRA
Waste Number (Resource Conservation and Recovery Act)
U044
NFPA 704 Rating
2-0-0
DOT
(U.S. Department of Transportation)
ORM-A
IMO
(International Maritime Organization)
6.1, poisonous substance
If you cannot patch the container or catch the liquid as it leaves the container, follow standard containment procedures. These include building a containment pond of soil, sand, clay, or other absorbent materials or digging a containment pit. A pit is preferable to a pond because it more easily controls the generation of vapors: The generation of vapors is much slower from a liquid that has a small surface area exposed to the atmosphere than from a considerable larger area such as a pond. However, ground containment may be more severe with a pit than a pond. These decisions w ill be governed by the terrain, available equipment, and amount of product spilled.
Experiment with applying different types of foam to limit vapor generation. Some foams may be totally inadequate, while others may help slow evaporation. If you use foams, make sure they do not aggravate the situation. Any containment pit or pond must also be large enough to handle the additional volume of liquid the foam produces.
If you decide on a pit, use sheeting of compatible material to slow the generation of vapors. One reference suggests pouring water over the surface of the chloroform to effectively blanket the product. Only use this procedure if it does not generate toxic decomposition products.
Once you contain the product, you can vacuum or pump it into secure containers. Absorb any remaining liquid with soil, clay, sand, fly ash, sawdust, straw, or cement powder. You must dispose of absorbed material as w ell as contaminated soil in accordance with federal, state, and local regulations.
Prevent chloroform from entering sewers and waterways by damming all entrances to sewer openings and manholes and diverting the liquid’s flow away from streams, rivers, or lakes. If the liquid does enter a waterway, notify all downstream users of the water immediately. The product, very slightly soluble with a specific gravity of 1.49, will sink below the water’s surface. In slow-moving waterways, the product gathers in low places. Use underwater dams to keep the product from flowing downstream. Pump any material so contained from beneath the water into secure containers or containment devices.
Another technique to use if the product enters a waterway is to divert the flow into a holding area until you can remove the product. Remove any dissolved product by aerating the water. Environmental authorities should monitor the situation and determine when the water is safe.
You can further treat the water by adding activated charcoal or peat moss and then agitating. In either mitigation technique—adsorption or absorption — the capturing medium holds the hazardous material and is present in the material throughout handling and disposal. (Take care to prevent a new release of the product.
GLOSSARY
Absorption—the penetration of one substance into the inner structure of another substance.
Adsorption—the adherence of one substance onto the surface of another substance.
Aeration—the process by which air is passed through another substance (sparging); also called air stripping, which is the spraying of the liquid or gas into the air to remove the contaminant.
Basic solution—solution of a substance in water that has a pH higher than 7.0.
Carcinogenic—the ability to cause cancer.
Evaporation —the process by w hich a liquid changes to a vapor; always accompanied by an increase in energy of the molecules evaporating.
Halogen —a family of elements (group VIIA on the Periodic Table of the Elements) consisting of fluorine, chlorine, bromine, and iodine.
Hydrocarbon—a chemical compound containing only hydrogen and carbon.
ORM-A—the DOT designation for “Other Regulated Material.” The “A” designation is for materials that have an anesthetic, irritating, noxious, toxic, or other similar property that can cause an extreme annoyance or discomfort to passengers or crew if a leak occurs during transportation.
STEL—Short Term Exposure Limit (The OSHA term is PEL, or Permissible Exposure Limit), or the maximum to which a person may be exposed for a short time—either 10 or 15 minutes, whichever is specified.
TLV-TWA—Threshold Limit ValueTime Weighted Average. The weighted average of a material to which a person may be exposed 40 hours a week with no ill effects. At no time during the 40 hours should the STEL or PEL be surpassed.
Vapor Pressure—the pressure exerted by a gas or vapor on the sides of its container, produced by the molecules of the product colliding with the container wall. The higher the temperature, the more energy is absorbed by the molecules, thus increasing molecular motion (vibrations) and the number of collisions with the wall. All liquids possess a vapor pressure. For reporting purposes, vapor pressure is measured near room temperature since it is assumed that the liquid will be stored at or near this temperature. The vapor pressure of chloroform is approximately 3 pounds per square inch absolute (psia) at 68°F.
Volatile—the capability of evaporating rapidly at normal temperatures and pressures.
FIRE SITUATION
Since chloroform is nonflammable, firefighters and other emergency responders tend to ignore it in a fire situation and concentrate all their efforts on extinguishing the fire. Although your orders may be to fight the fire and prevent its spread, exercise caution when dealing with all closed containers ..holding liquids, even those classified as nonflammable.
In a fire, radiated heat or conducted heat (from flame contact) transmits energy to the container, which transfers much of it to its contents. As the liquid absorbs this energy, the evaporation process speeds up (because of the speeding up of the molecular motion), and the vapor pressure climbs inside the containers (see glossary). If the pressure cannot be relieved (by some sort of pressure-relief device) faster than it is generated, the design strength of the container may be surpassed and the container fails catastrophically. This catastrophic failure is accompanied by flying shrapnel and the spewing of the contents over large areas. Keep all exposed containers cool by applying water from a safe distance.
If the container is leaking liquid or venting vapors, the dangerous decomposition of chloroform mentioned above occurs on contact with flame. The carbon monoxide produced is flammable, and most of it will burn if ignited under the proper circumstances (within the flammable range). Phosgene, chlorine, and hydrogen chloride will be carried up in the thermal column but eventually cool and sink to the ground. Fortunately, the turbulence the fire causes is usually enough to disperse these gases, but always take care to protect the lungs, eyes, and skin of all exposed.
You can use water fog or spray to disperse any vapors of chloroform that are released as long as the water does not contact a pool of the liquid. Remember, hot water accelerates the decomposition of the product.
You can fight the surrounding fire with routine techniques as long as you keep exposed containers cool, keep excess water from liquid chloroform, and provide protection for the decomposition products. Consider evacuation downwind of the fire early because of those decomposition products. Consult environmental authorities whenever firefighting techniques present a possibility of the spread of contamination.
FIRST AID
Move victims of inhalation to fresh air and keep them quiet and warm. Administer artificial respiration only if their breathing has stopped or becomes difficult, but be careful of exposure to the product in the victim’s lungs and/or vomit. Seek medical attention immediately.
If the victim has ingested chloroform and is conscious, administer a strong solution of salt water. Induce vomiting if medical attention is not immediate. Do not try to make an unconscious person drink anything.
In case of eye contact with chloroform, flush the eyes immediately with water for 15 minutes, occasionally opening the eyelids. Medical attention is also necessary.
For skin contact, remove all contaminated clothing immediately. Wash all contacted body areas with large amounts of soap and water, and seek medical attention.
PROTECTIVE CLOTHING AND EQUIPMENT
Choose clothing and protective equipment that prevent chloroform liquid or vapor from coming in contact with the eyes, skin, or respiratory system. Select splash-proof chemical goggles and face shields for eye protection, and use positive-pressure self-contained breathing apparatus. Rubber boots, gloves, and aprons offer some protection, but wear total encapsulating suits if contact with chloroform is possible. Manufacturers of such suits claim that suits made of nitrile-butadiene rubber (NBR), polyurethane (PUR), polyvinyl alcohol (PVOH), and Viton offer protection.
