What is the primary chemical used in dry-cleaning?

The primary chemical used in dry-cleaning is perchloroethylene, commonly known as "perc." This solvent is favored for its effectiveness in lifting stains and cleaning delicate fabrics without damaging them. Perc is a key component in many dry-cleaning solutions due to its ability to dissolve oils and greases while being non-flammable. This characteristic makes it suitable for a process where clothing items cannot be submerged in water without risking shrinkage or fading.

In contrast, the other substances listed have specific industrial or health-related applications but do not serve as solvents or cleaning agents in the dry-cleaning process. Polyvinylchloride is primarily a plastic material used in various manufacturing applications. Asbestos is known for its insulating properties and health risks, specifically related to respiratory diseases, and it is not used in dry-cleaning practices. Lead is a toxic heavy metal that has been widely regulated due to its health hazards, particularly in paint and plumbing, and has no relevance to the dry-cleaning industry. Therefore, perchloroethylene is recognized as the primary chemical in the dry-cleaning process.