Final answer:
Chlorofluorocarbons (CFCs) have been used as propellants in spray cans, in refrigeration systems, and to make foam products. However, they have been phased out due to their harmful effects on the ozone layer.
Step-by-step explanation:
Chlorofluorocarbons (CFCs) are synthetic chemical compounds that have been used for various purposes. They have been used as propellants in spray cans, in refrigeration systems, and to make foam products. However, they have been phased out due to their harmful effects on the ozone layer.