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Wednesday, 8 February 2012

TETRACHLOROETHYLENE (TCE)


TETRACHLOROETHYLENE (TCE)

Tetrachloroethylene is a synthetic solvent which became popular as a dry cleaning fluid in 1930s. Tetrachloroethylene, C2Cl4 is also known as PERK, PERC, Perchloroethylene, Dowper, Perclene, tetralex, tetravec, and tetraguer. It’s boiling point and melting point is 121.1 0C and 22.10C respectively. It almost insoluble , the solubility is 0.015g/100mL in water at 25 0 C. It is colourless, has an ether-like odour, and denser than water.

Apart from its main use as the principal solvent in professional and coin-operated dry cleaning plants, tetrachloroethylene is used as a metal degreaser, a textile cleaner, a raw material for the manufacture of other chemicals, and as a dielectric or electrical insulating fluid, in some cases replacing polychlorinated biphenyls (PCBs) in electrical equipment such as transformers or capacitors.

Tetrachloroethylene enters the atmosphere mainly through evaporation, thus contributing to the atmospheric pool of volatile organic carbon compounds; air pollutants which can create smog. Once in atmosphere, tetrachloroethylene may be tranported for considerable distance and deposited with precipitation, sometimes in remote areas and far from point of release.  Fortunately,  tetrachloroethylene which enters the atmosphere will eventually degrades due to the action of sunlight.

Organisms are generally exposed to elevated concentrations of tetrachloroethylene only through industrial spills and other accidental release. At high concentrations, test have shown that tetrachloroethylene can be acutely toxic, especially to fish. Exposure to high concentrations can cause cancer in mice and rats and in some cases are toxic to mice embryos and fetuses.

The use of tetrachloroethylene is controlled by various laws, regulations and agreements designed to protect the environment and human health.

The Canadian Environmental Protection Act (CEPA) requires that the federal Ministers of the Environment and health compile a list of those substances that need to be assessed, on a priority basis, in terms of their environmental and health effects. Tetrachloroethylene was on the first priority substances listed under CEPA, announced in 1989. It was judged to be toxic to the environment in part because atmospheric concentrations of the substance may be sufficient to cause adverse effects to trees. The federal government is currently developing controls to reduce environmental exposure of tetrachloroethylene.

Therefore, as a professional environmental consultants we suggest all our friends, partners and clients to take note on the usage of this material by performing a Life Cycle Analysis on all our products – the quantified version please.  From there, we should embark on our Environmental Supplier Audit before narrowing down on these PCD & TCE substances.  Remember our classic ‘Fish & Mother-in-Law’ or Sweet-sour Ikan Kerapu’ story?

High concentrations of tetrachloroethelne can cause dizzines, headache, sleepiness, confusion, nausea, difficulty in speaking and walking, unconciousness and death. In industry, most workers are exposed to levels lower than those causing obvious nervous system effects. Results from some studies indicate that women who work in dry cleaning industries where exposures to tetrachloroethylene can be quite high may have more menstrual problems and spontaneous abortions than women who are not exposed.
TCE can cause/ effect the health

But it  is …..when it enter the environment,
It only can be exposed when……
Uses
  • Used in the textile industry for dry-cleaning & for processing & finishing
  • In both cold cleaning & vapor degreasing of metals,
  • As a chemical intermediate in the synthesis of fluorocarbon 113, 114 & 116
  • For silicones insulating fluid & cooling gas in electric transformers
We should phase out their usage after successfully identified other viable alternatives. 
Sekitar Synergy SDN BHD
Environmental Consulting Unit
Via MD’s Desk

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