Phthalates, which are incorporated into plastics as plasticizers, comprise approximately 70% of the U.S. plasticizer market; phthalates are by design not covalently bound to the polymer matrix, which makes them highly susceptible to leaching. Phthalates are contained in plastics at high percentages. For example, they can contribute up to 40% by weight to intravenous medical bags and up to 80% by weight in medical tubing.Vinyl products are pervasive—including toys, car interiors, shower curtains, and flooring—and initially release chemical gases into the air. Some studies indicate that this outgassing of additives may contribute to health complications, and have resulted in a call for banning the use of DEHP on shower curtains, among other uses. Japanese car companies Toyota, Nissan, and Honda eliminated the use of PVC in car interiors since 2007.