Chloroform

Chloroformis anorganic compoundwithformulaCHCl3. It is one of the four chloromethanes.The colourless, sweet-smelling, dense liquid is atrihalomethane, and is considered hazardous. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][1]

Chloroform is slightly soluble in water. It is miscible with alcohol, benzene, petroleum ether, carbon tetrachloride, carbon disulfide and oils. Chloroform reacts vigorously with strong caustics, strong oxidants, chemically active metals such as aluminium, lithium, magnesium, sodium or potassium, and acetone, causing fire and explosion hazards. It can attack plastic, rubber and coatings. Chloroform decomposes slowly under the influence of light and air. It also decomposes on contact with hot surfaces, flames or fire, forming irritating and toxic fumes, which consist of hydrogen chloride, phosgene and chlorine. [2]

 

Uses [2]

 

Chloroform is primarily used in the production of refrigerants (e.g. chlorofluorocarbon (CFC)-22, fluorocarbon-22), in the production of plastics (especially vinyl chloride) and in the manufacture of other chemicals. Chloroform is used as an extraction solvent for fats, oils, greases, rubber, waxes, gutta-percha, resins, lacquers, floor polishes, artificial silk manufacture, gums and adhesives. It is utilised as an industrial solvent in the extraction and purification of some antibiotics, alkaloids, vitamins and flavours. It is used as a solvent in organic chemistry, in photography and in making dyes, drugs and pesticides. Other uses are as a dry cleaning agent to remove spots, as a fumigant and in fire extinguishers to lower the freezing temperature of carbon tetrachloride. Chloroform formulated with other ingredients is used to control screw worm in animals. Chloroform is steadily being replaced by less toxic solvents and may no longer be used in some of these applications. Its use as an inhaled anaesthetic during surgery has already been largely discontinued.

 

Sources of Emission & Routes of Exposure

 

Sources of Emission [2]

 

  • Industry sources: Chloroform may enter the environment from a number of sources, including industrial effluent, municipal waste treatment plant discharges, hazardous waste sites, sanitary landfills and spills.
  • Diffuse sources: Chloroform can be formed as a result of the chlorination of naturally occurring organic materials found in raw water supplies. Hence, water treated with chlorine (drinking water, swimming pool) may be contaminated with trace amounts of chloroform.
  • Natural sources: There are no natural sources for chloroform.
  • Transport sources: There are no mobile sources for chloroform.
  • Consumer products: There are no consumer products that contain chloroform.

 

Routes of Exposure [3]

 

  • Drinking water or beverages made using water containing chloroform.
  • Breathing indoor or outdoor air containing it, especially in the workplace.
  • Eating food that contains it.
  • Skin contact with chloroform or water that contains it, such as in swimming pools.

 

Health Effects [4]

 

Acute Effects

 

  • The major effect from acute inhalation exposure to chloroform in humans is central nervous system depression. At very high levels (40,000 ppm), chloroform exposure may result in death, with concentrations in the range of 1,500 to 30,000 ppm producing anaesthesia, and lower concentrations (<1,500 ppm) resulting in dizziness, headache, tiredness, and other effects.
  • Effects noted in humans exposed to chloroform via anaesthesia include changes in respiratory rate, cardiac effects, gastrointestinal effects, such as nausea and vomiting, and effects on the liver and kidney. Chloroform is not currently used as a surgical anaesthetic.
  • In humans, a fatal oral dose of chloroform may be as low as 10 mL (14.8 g), with death due to respiratory or cardiac arrest.
  • Tests involving acute exposure of animals have shown chloroform to have low acute toxicity from inhalation exposure and moderate acute toxicity from oral exposure.

 

Chronic Effects

 

  • Chronic exposure to chloroform by inhalation in humans is associated with effects on the liver, including hepatitis and jaundice, and central nervous system effects, such as depression and irritability.
  • Inhalation exposures of animals have also resulted in effects on the kidney.
  • Chronic oral exposure to chloroform in humans has resulted in effects on the blood, liver, and kidney.
  • EPA has not established a Reference Concentration (RfC) for chloroform.
  • The California Environmental Protection Agency (CalEPA) has established a chronic reference exposure level of 0.3 milligrams per cubic metre (mg/m3) for chloroform based on exposures resulting in kidney and liver effects in rats.
  • ATSDR has established an acute inhalation minimal risk level (MRL) of 0.5 mg/m3 (0.1 ppm) based on exposures resulting in liver effects in mice, an intermediate inhalation MRL of 0.2 mg/m3 (0.05 ppm) based on worker exposures resulting in liver effects in humans, and a chronic inhalation MRL of 0.1 mg/m3 (0.02 ppm) also based on liver effects in humans.
  • The Reference Dose (RfD) for chloroform is 0.01 milligrams per kilogram per day (mg/kg/d) based on exposures resulting in fatty cyst formation in the livers of dogs.

 

Reproductive/Developmental Effects

 

  • Little information is available on the reproductive or developmental effects of chloroform in humans, via any route of exposure. A possible association between certain birth outcomes (e.g., low birth weight, cleft palate) and consumption of contaminated drinking water was reported.       However, because multiple contaminants were present, the role of chloroform is unclear.
  • Animal studies have demonstrated developmental effects, such as decreased foetal body weight, foetal resorptions, and malformations in the offspring of animals exposed to chloroform via inhalation.
  • Reproductive effects, such as decreased conception rates, decreased ability to maintain pregnancy, and an increase in the percentage of abnormal sperm were observed in animals exposed to chloroform through inhalation.
  • Animal studies have noted decreased foetal weight, increased foetal resorptions, but no evidence of birth defects, in animals orally exposed to chloroform.

 

Cancer Risk

 

  • No information is available regarding cancer in humans or animals after inhalation exposure to chloroform.
  • Epidemiologic studies suggest an association between cancer of the large intestine, rectum, and/or bladder and the constituents of chlorinated drinking water, including chloroform. However, there are no epidemiologic studies of water containing only chloroform.
  • Chloroform has been shown to be carcinogenic in animals after oral exposure, resulting in an increase in kidney and liver tumours.
  • EPA considers chloroform to be a probable human carcinogen and has ranked it in EPA’s Group B2.
  • EPA has determined that although chloroform is likely to be carcinogenic to humans by all routes of exposure under high-exposure conditions that lead to cell death and regrowth in susceptible tissues, chloroform is not likely to cause cancer in humans by any route of exposure under exposure conditions that do not cause cell death and regrowth. Therefore, EPA has not derived either an oral carcinogenic potency slope or an inhalation unit risk for chloroform.

 

Safety [5]

 

First Aid Measures

 

  • Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. WARM water MUST be used. Get medical attention.
  • Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention.
  • Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention.
  • Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention.
  • Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation.
  • WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious or corrosive. Seek medical attention.
  • Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. If large quantities of this material are swallowed, call a physician immediately. Loosen tight clothing such as a collar, tie, belt or waistband.

 

Exposure Controls & Personal Protection

 

Engineering Controls

 

  • Provide exhaust ventilation or other engineering controls to keep the airborne concentrations of vapours below their respective threshold limit value. Ensure that eyewash stations and safety showers are proximal to the workstation location.

 

Personal Protective Equipment

 

The following personal protective equipment is recommended when handling chloroform:

  • Splash goggles;
  • Lab coat;
  • Vapour respirator (be sure to use an approved/certified respirator or equivalent);
  • Gloves.

 

Personal Protection in Case of a Large Spill:

 

  • Splash goggles;
  • Full suit;
  • Vapour respirator;
  • Boots;
  • Gloves;
  • A self-contained breathing apparatus should be used to avoid inhalation of the product.

*Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.

Regulation

 

United States [6]

 

OSHA: The Occupational Safety & Health Administration has set the following Permissible Exposure Limit (PEL) for chloroform:

  • General Industry: 29 CFR 1910.1000 Table Z-1 – 50 ppm, 240 mg/m3 Ceiling;
  • Construction Industry: 29 CFR 1926.55 Appendix A – 50 ppm, 240 mg/m3 Ceiling;
  • Maritime: 29 CFR 1915.1000 Table Z-Shipyards – 50 ppm, 240 mg/m3 TWA

 

ACGIH: The American Conference of Governmental Industrial Hygienists (ACGIH) has set a Threshold Limit Value (TLV) for chloroform of 10 ppm, 49mg/m3 TWA; Appendix A3 – Confirmed Animal Carcinogen with Unknown Relevance to Humans

 

NIOSH: The National Institute for Occupational Safety and Health (NIOSH) has set a Recommended Exposure Limit (REL)for chloroform of 2 ppm, 9.78mg/m3 STEL (60 Minutes); Appendix A – NIOSH Potential Occupational Carcinogens

 

Australia [7]

 

Safe Work Australia: Safe Work Australia has established a time weighted average (TWA) concentration of chloroform of 2ppm or 10mg/m3 for a 40 hour work-week.

 

References

 

  1. http://en.wikipedia.org/wiki/Chloroform
  2. http://www.npi.gov.au/resource/chloroform-trichloromethane
  3. http://www.atsdr.cdc.gov/toxfaqs/TF.asp?id=52&tid=16
  4. http://www.epa.gov/ttn/atw/hlthef/chlorofo.html
  5. http://www.sciencelab.com/msds.php?msdsId=9927133
  6. https://www.osha.gov/dts/chemicalsampling/data/CH_227600.html
  7. http://www.safeworkaustralia.gov.au/sites/swa/about/Publications/Documents/772/Workplace-exposure-standards-for-airborne-contaminants.docx

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