Polypropylene (PP), is a thermoplastic polymer providing good chemical and heat resistance at a reasonable cost. Polypropylene is rugged and unusually resistant to many chemical solvents, bases and acids.
PP is chemically stable; composed of hydrogen and carbon atoms. When polypropylene is incinerated only water vapor and carbon dioxide are produced. The calorific heating value is similar to oil. Among fossil fuel-based resins, only polypropylene can be considered sustainable under a reference system created by non-profit environmental solutions provider Clean Production Action and sustainability consultant Pure Strategies. (Plastics News - October 5, 2009)
Most polypropylene resin is natural in color (without additives) and complies with FDA regulations for food contact applications. Some products are produced with additives, including carbon black, that inhibit ultraviolet light degradation.