If you were to create a recipe for plastics, you’d need a very big cookbook. In addition to fossil fuel-based building blocks like ethylene and propylene, this ubiquitous material is made from a dizzying amalgam of more than 16,000 chemicals — colorants, flame retardants, stabilizers, lubricants, plasticizers, and other substances, many of whose exact functions, structures, and toxicity are poorly understood.
What is known presents many reasons for concern. Scientists know, for example, that at least 3,200 plastic chemicals pose risks to human health or the environment. They know that most of these compounds can leach into food and beverages, and that they cost the U.S. more than $900 billion in health expenses annually. Yet only 6 percent of plastic chemicals — which can account for up to 70 percent of a product’s weight — are subject to international regulations.
