Phthalates are aromatic compounds that are found throughout the environment and are used in some plastics, solvents, detergents, lubricating oils, and cosmetics. There is concern that phthalates can cause cancer or reproductive problems in people and animals. In 1998, the U.S. Consumer Product Safety Commission (CPSC) conducted a study of the amount of one type of phthalate, diisononyl phthalate (DINP) that can leach from children's products such as teethers, rattles, and toys. This study set an international standard concentration for DINP in children's products that is 10 times higher than the level found to cause health problems in laboratory animals. The results of a study released in 2000 by the Centers for Disease Control and Prevention (CDC) and the National Toxicology Program (NTP) found four types of phthalates in the urine of more than 75% of test subjects, indicating that the phthalates that humans are exposed to in the environment are metabolized. The study was not designed to provide information on the health risks of phthalates or on the degree of exposure of the United States population, and follow-up studies by the CDC are measuring phthalate concentrations in a larger part of the population, including children six years old and older.