For dry cleaning, in the place of tetrachloroethene

For dry cleaning, in the place of tetrachloroethene, liquefied carbon dioxide with suitable detergent is an alternative solvent. What type of harm to the environment will be prevented by stopping use of tetrachloroethene? Will use of liquefied carbon dioxide with detergent be completely safe from the point of view of pollution. Explain.

(i) Tetrachloroethene, ${{Cl}{2}}$C=
{2}}$ is suspected to be carcinogenic and also contaminates the ground water. This harmful effect will be prevented by using liquefied
${{CO}{2}}$ along with suitable detergent.
(ii) Use of liquefied ${{CO}
{2}}$ along with detergent will not be completely safe because most of the detergents are non-biodegradable and they cause water pollution. Moreover, liquefied
${{CO}_{2}}$ will ultimately enter into the atmosphere and contribute to the green house effect.