A large number of fabrics and garments cannot be washed in water without shrinking, fading or felting. To avoid damage of this kind dry cleaning (using solvents) is strongly recommended: this method requires special machinery and procedures to prevent the solvents from being dispersed into the environment. The most commonly used solvent for this type of washing is tetrachloroethylene, commonly called Perc, which at present provides the best cleaning results possible. Various types of solvents have been launched on the market in recent years: some are hydrocarbon-based and others silicone-derived. If all these solvents were used respecting the proper procedures the effect on the environment would not be as negative as it is currently, and perhaps inappropriately, described.