They use a solvent, called methylene chloride (also known as dichloromethane) to wash the tea. They then heat the tea to 104 F and most of the solvent evaporates. The FDA allows 5 parts per million to remain in the tea. The World Health Organization has determined that this chemical may cause cancer in humans and result in abdominal pain!
Drink fermented Pu’erh! The method of fermentation nullifies the caffeine. Many use this tea as a sleep aid.