Tetrachloroethylene (C2Cl4): Properties, Production & Uses

Ans. Tetrachloroethene is a synthetic chemical used in the dry cleaning of materials, notably clothing.

• It's also utilized in the degreasing of metal components and the production of other chemicals.
• As it dissolves oil and filth without harming clothes, it is utilized as a powerful dry-cleaning solvent.
• Tetrachloroethylene is one of the active ingredients in paint strippers and spot removers.
• However, because this molecule is known to be carcinogenic and a groundwater pollutant, it is presently being substituted with liquified carbon dioxide and hydrogen peroxide and detergent.

Ans. Tetrachloroethylene concentrations in ambient air have decreased in recent decades as the use of tetrachloroethylene has decreased. Tetrachloroethylene has also been found in drinking water sources affected by contaminated groundwater.

Occupational exposure to tetrachloroethylene occurs mostly in industries that use the chemical (for example, numerous dry-cleaning establishments) and in companies that manufacture it. Over the last few decades, new dry-cleaning technology and procedures have resulted in significantly lower occupational exposure.

Ans. Acute inhalation exposure of humans to tetrachloroethylene vapours causes irritation of the upper respiratory tract and eyes, kidney dysfunction, and, at lower concentrations, neurological effects such as reversible mood and behavioural changes, coordination impairment, dizziness, headache, sleepiness, and unconsciousness. Acute inhalation exposure to high amounts of tetrachloroethylene has been shown to have consequences on the liver, kidneys, and central nervous system (CNS) in animals. Tetrachloroethylene toxicity from inhalation and oral exposure was shown to be minimal in acute animal studies in mice.

Ans. In chronic cases, one can suffer from the following:

• In humans, the main impacts of prolonged inhalation exposure to tetrachloroethylene are neurological effects, such as sensory complaints including headaches, cognitive and motor neurobehavioral deficits, and colour vision abnormalities.
• Other human impacts include liver damage, renal effects, immunological and hematologic effects, and effects on development and reproduction, all of which are more common at greater doses.
• Chronic inhalation exposure to tetrachloroethylene has been shown to have effects on the liver, kidneys, and CNS in animal studies.

Ans. The possible reproductive/developmental effects of tetrachloroethylene are as follows:

• In investigations of persons occupationally exposed to tetrachloroethylene, unfavourable reproductive consequences such as menstruation problems, changed sperm structure, and lower fertility have been documented. The evidence, however, is inconclusive.
• Some investigations of pregnant women who were exposed to tetrachloroethylene and other solvents in their drinking water imply a link between tetrachloroethylene exposure and birth abnormalities, although definite conclusions cannot be formed due to the limitations of these research.
• In animals exposed to high amounts of tetrachloroethylene by inhalation, increased foetal resorptions and effects on the foetus have been recorded.

Ans. Tetrachloroethylene can be associated to cancer in the following ways:

• Studies of dry cleaners exposed to tetrachloroethylene have found links between tetrachloroethylene exposure and numerous forms of cancer, including bladder cancer, non-Hodgkin lymphoma, and multiple myeloma. There's also some evidence of links to esophageal cancer, renal cancer, cervical cancer, and breast cancer.
• Inhalation and gavage (experimentally inserting the chemical in the stomach) exposure in mice resulted in an increased incidence of liver cancers, whereas inhalation exposure in rats resulted in kidney and mononuclear cell leukemias.
• Based on suggestive data in epidemiological studies and definitive evidence in rats (mononuclear cell leukaemia) and mice, the EPA has categorised tetrachloroethylene as probably carcinogenic to humans by all routes of exposure (increased incidence of liver tumours). Tetrachloroethylene is classed as possibly harmful to humans by the International Agency for Research on Cancer (IARC) (Group 2A).

Ans. The physical properties of tetrachloroethylene are as follows:

• Tetrachloroethylene is a colourless, non-flammable liquid with a distinct sweet odour that has a 1 ppm olfactory threshold.
• Tetrachloroethylene has the chemical formula C₂Cl₄ and a molecular weight of 165.82 g/mol.
• At 25 °C, tetrachloroethylene has a vapour pressure of 18.47 mm Hg and a log octanol/water partition coefficient (log Kow) of 3.40.

Ans. The distribution of tetrachloroethylene in the environment is predicted to be 76.39 percent to 99.69 percent in the air, 0.23 percent to 23.2 percent in the water, 0.06^-7 percent in the soil, and the rest in the sediment and biota. The lifespan in the atmosphere is predicted to be around 2 months in the Southern Hemisphere and 5–6 months in the Northern Hemisphere, according to a survey conducted in 1987.

Phosgene, trichloroacetyl chloride, hydrogen chloride, carbon dioxide, and carbon monoxide are some of the degradation products that have been seen in a laboratory. Tetrachloroethylene is a persistent organic compound that is destroyed by hydrolysis. Trichloroethylene, dichloroethylene, vinyl chloride, ethylene, and ethane are some of the breakdown products produced by reductive dechlorination under anaerobic circumstances. Where CFC-11 (CCl₃F) is 1, it has an ozone depletion potential of 0.005.