Polypropylene chemical-resistant sheets and bars are made with a semi-crystalline thermoplastic material that provides a continuous-use temperature range of -4°F (-20°C) to 212°F (100°C). They are durable, chemical resistant, and are easily processed. They are also suitable for contact with food and are often used as electrical insulators. They withstand contact with many common sterilization materials including acids, alkalis, and solvents. These bars and sheets resist fatigue when flexing under load and are commonly in orthotics and prosthetics applications.