Plastics—such as water bottles, shopping bags, and other waste materials—litter the planet and take an extremely long time to break down. However, despite posing a major environmental problem, plastics used in artifacts present a different challenge: museum conservators are racing against time to prevent them from rapidly deteriorating. They are working with scientists to better understand the decay of plastic artifacts in order to preserve them for future generations. Museums around the world exhibit artworks created from these materials, including avant-garde sculptures, high-end fashion, and designer furniture. The unstable nature of plastics has created major challenges for museums attempting to preserve these valuable objects. Different types of plastics degrade at different rates depending on their composition and surrounding environment. Compared with modern plastics, the early plastic materials used in the 19th and early 20th centuries were relatively unstable. This issue was further compounded by the fact that early artists had limited knowledge of how to properly mix plastics with other materials. Thus, these mixtures may naturally separate over time, especially when exposed to temperature fluctuations. As a result, artifacts made from plastics during this period—such as historical household items—are particularly vulnerable to deterioration. Even if a plastic artwork is carefully conserved, it may still crack and crumble. Four kinds of plastics are particularly susceptible to crumbling—cellulose acetate, cellulose nitrate, polyvinyl chloride, and polyurethane foam. Among them, cellulose acetate and cellulose nitrate are considered especially “malignant” because the molecules released during the breakdown of these plastics may drift onto nearby artifacts, causing corrosion or staining. Therefore, conservators need to detect damage to plastic artifacts even before it becomes visible. One primary challenge for museums is identifying the plastics used in the creation of artifacts. Because many museums do not have access to laboratory equipment, conservators often rely on low-tech methods such as touching and sniffing materials. For instance, when tapped, some plastics may produce either harsh or dull sounds. After plastics begin to decay, they can release a surprising range of odors, including the smells of vinegar, burnt hair, and car tires. In addition, conservators may conduct experiments to determine what types of plastics were used and how they break down over time. Once conservators identify the plastic in an artifact, they can begin taking steps to preserve it. Since each type of plastic has its own chemical characteristics, conservation methods must be tailored to the specific nature of the plastic. In addition to repairing damage to artifacts, conservators and researchers are also working with artists to help them better understand the pitfalls of creating art from different plastic materials. They hope to help artists ensure that their works can endure over time.