Tetrachloroethene & Trichloroethane
Table of Contents
Maximum amount allowed in water:
What are tetrachloroethene & trichloroethane?
Tetrachloroethene [C2Cl4] is a colourless, nonflammable organic liquid used in dry-cleaning solutions, as an industrial solvent and as an agent for expelling or destroying parasitic intestinal worms.
Trichloroethane [C2HCL3] is a heavy, colourless, toxic liquid used to degrease metals, to extract oil from nuts and fruit, as a refrigerant, in dry cleaning, and as a fumigant. It is also known as trichloroethylene (TCE).
Are they in the source?
Levels of tetrachloroethene in surface water are generally below 3 μg/litre, while trichloroethane is normally less than 1μg/litre.
How do they get into water?
Poor handling and improper disposal are the main ways in which these chemicals get into a water source. This often happens by way of seepage from landfills or a spill. Their presence suggests industrial effluent is contaminating the water supply at some stage.
Do they pose a risk to health?
At high concentrations, tetrachloroethene has been shown to cause central nervous system depression. Lower concentrations have been reported to damage the liver and kidneys. The international agency for research on cancer has concluded that tetrachloroethene is more than likely carcinogenic.
How is it checked for?
Where there is a landfill nearby a water source, the authorities must carry out continuous checks for these parameters.
How are they removed from water?
Tetrachloroethene can be removed from drinking water by adsorption onto
granular activated carbon or by aeration. Trichloroethane can be removed by aeration, or
by adsorption onto granular activated carbon