Laundry detergent pods (or packs or liquitabs) are water-soluble pouches containing highly concentrated laundry detergent, softener and other laundry products. Notable brands of these packs include All, Arm & Hammer, Gain, Purex, Persil and Tide. They first became popular in February 2012 when they were introduced by Procter & Gamble as Tide Pods.The chemistry of laundry detergent packs is the same as in liquid detergents (including alkylbenzenesulfonates). The dissolvable packets are typically made of polyvinylalcohol (PVA) or a derivative of PVA. Although the formulas are similar, a detergent pack's liquids may contain 10% water compared to 50% in liquid detergents.MonoSol is one of the companies that develops the water-soluble film used for laundry and dishwasher detergent packs, used by brands including Tide, with roughly $250 million in annual sales and controlling around 90-percent of the market. The film is designed to be soluble in cold water.Laundry pods are estimated to make up about 15% of the $7 billion-a-year U.S. laundry detergent market sales according to market researcher Nielsen NV. Laundry pods were advertised as a way to reduce wasted use of powdered and liquid detergent by having precise measurements for a load. For large loads, most brands recommend two pods, with Tide suggesting up to three. Detergent pods cost significantly more than liquid detergent for equivalent laundry loads.