Tetra chloroethene was earlier used as solvent for dry cleaning but it contaminates ground water and carcinogenic hence it is replaced by

Tetra chloroethene (Cl₂C=CCl₂) was earlier used as solvent for dry cleaning. The compound contaminates the ground water and is also a suspected carcinogen. The process using this compound is now being replaced by a process, where liquefied carbon dioxide, with a suitable detergent is used.