Chloroform, also known as trichloromethane. Colorless and transparent liquid. Has a special odor. Sweet taste. Highly refractive, non-combustible, heavy, volatile.

The pure product is sensitive to light and will gradually decompose with oxygen in the air when exposed to light to produce highly toxic phosgene (carbonyl chloride) and hydrogen chloride.

1. Physical and chemical properties of chloroform

Chloroform is a compound formed when three hydrogen atoms in methane are replaced by chlorine atoms, also known as trichloromethane, or “chloroform”.

It is a colorless, transparent, volatile, non-combustible, slightly sweet liquid. Strong refractive property. Relative molecular mass 119.38.

Relative density 1.4984(15℃). Melting point -63.5℃.

Boiling point 62℃. Insoluble in water: 1.062 at 0℃, 0.895 at 10℃, 0.822 at 20℃, 0.776 at 30℃, miscible with organic solvents such as ethanol, ether, petroleum ether, benzene, carbon tetrachloride and carbon disulfide.

Under the action of light, it can be oxidized by air into a highly toxic phosgene (COCl2).

Chloroform can be added to 1 to 2% of ethanol as a stabilizer, so that the resulting phosgene into diethyl carbonate, thereby eliminating toxicity.

Narcotic, commonly used as anesthetics in the past, can stimulate the mucous membranes and quickly from the state of excitement to sleepiness, dizziness, anesthesia, and in serious cases can cause death.

Because of its toxicity, it is not used for anesthesia, but it is still commonly used as a solvent in the chemical industry such as pharmaceuticals, plastics, oil additives and organic synthesis.

It is a common pollutant in the atmosphere and water environment.

1.9μg/L concentration increases the risk of cancer by 100,000%. Drinking water should not contain chloroform,

but chlorination disinfection of drinking water containing organic contaminants, often generated by chromatography can detect the concentration of chloroform.

Therefore, disinfection of drinking water with ozone than with chlorination in a more reasonable health. The maximum allowable concentration in air is 50 mg/kg.

2. Chloroform role and use

Organic synthesis raw materials, mainly used to produce Freon (F-21, F-22, F-23), dyes and drugs, in medicine, often used as anesthetics.

It can be used as solvent and extractant for antibiotics, spices, oils and fats, resins and rubber. Mixed with carbon tetrachloride can be made into a non-freezing fireproof liquid.

It is also used as an emitting agent for smoke agents, a fumigant for grains, and a standard liquid for calibrating temperature.

Industrial products are usually spiked with a small amount of ethanol so that the resulting phosgene interacts with ethanol to produce non-toxic diethyl carbonate.

Before using the industrial product can be added a small amount of concentrated sulfuric acid shaking after water washing, dried by calcium chloride or potassium carbonate, you can get chloroform without ethanol.

3. Chloroform precautions

(1) Overview of hazards

Health hazard: mainly acts on the central nervous system, has anesthetic effects, and is damaging to the heart, liver and kidneys. Acute poisoning:

Inhalation or absorption through the skin causes acute poisoning. Initially, there are symptoms of headache, dizziness, nausea, vomiting, excitement, wet and hot skin and mucous membrane irritation.

Later, mental disturbance, superficial breathing, loss of reflexes, coma, etc.

In severe cases, respiratory paralysis and ventricular fibrillation occur. It can be accompanied by liver and kidney damage.

In case of accidental poisoning, there is a burning sensation in the stomach, accompanied by nausea, vomiting, abdominal pain and diarrhea.

Anesthetic symptoms appear later.

The liquid state can cause dermatitis, eczema, and even skin burns.

Chronic effects: It mainly causes liver damage and symptoms such as indigestion, weakness, headache, insomnia, etc.

A few have kidney damage and chloroformophilia.

Environmental hazard: It is hazardous to the environment and can cause pollution to water bodies.

Flammability hazard: The product is non-flammable, toxic, a suspected carcinogen, and irritating.

(2) First aid measures

Skin contact: Remove contaminated clothing immediately and flush with plenty of running water for at least 15 minutes. Seek medical attention.

Eye contact: Immediately lift eyelids and flush thoroughly with plenty of running water or saline for at least 15 minutes. Seek medical attention.

Inhalation: Quickly remove from the scene to fresh air. Keep airway open. If breathing is difficult, give oxygen.

If breathing stops, give immediate artificial respiration. Seek medical attention.

Ingestion: Drink sufficient warm water and induce vomiting. Seek medical attention.

(3) Fire-fighting measures

Hazardous characteristics: Produces highly toxic phosgene when in contact with open flames or burning objects.

Under the action of air, moisture and light, the acidity increases and thus it is strongly corrosive to metals.

Harmful combustion products: hydrogen chloride, phosgene.

Fire-fighting methods: Firefighters must wear filtered gas masks (full face mask) or isolated breathing apparatus, wear full-body fire-resistant gas-proof clothing,and extinguish the fire upwind.

Extinguishing agents: fog water, carbon dioxide, sand and earth.

(4) Leak emergency treatment

Emergency response: Quickly evacuate people from the contaminated area of the spill to a safe area, and isolate and strictly limit access.

It is recommended that emergency response personnel wear self-contained positive pressure respirators and hazmat suits.

Do not touch the spill directly. Cut off the source of the spill if possible.

Small spills: Absorb with sand, vermiculite or other inert materials.

Large spill: Construct a dike or dig a pit to contain it. Cover with foam to reduce vapor hazard.

Transfer to tanker or special collector with pump, recycle or transport to waste disposal site for disposal.

(5) Operation disposal and storage

Operation precautions: Airtight operation with local exhaust. Operators must be specially trained and strictly follow the operating procedures.

It is recommended that operators wear direct type gas masks (half masks), chemical safety protective glasses,

anti-toxicant penetration overalls and chemical resistant gloves. Prevent vapors from leaking into the workplace air. Avoid contact with alkalis and aluminum.

Handle lightly to prevent damage to packaging and containers. Equipped with spill emergency handling equipment. Emptying the container may leave residual harmful substances.

(6) Storage precautions:

Store in a cool, ventilated warehouse. Keep away from fire and heat sources.

Store at a temperature not exceeding 30°C and relative humidity not exceeding 80%. Keep the container sealed.

It should be stored separately from alkali, aluminum and edible chemicals, and should not be mixed.

The storage area should be equipped with leak emergency treatment equipment and suitable shelter materials.