Polypropylene plastic, known for its versatility, durability, and recyclability, is widely used in various industries. It's a thermoplastic polymer that's lightweight yet resistant to chemicals, heat, and fatigue, making it ideal for packaging, automotive components, textiles (like ropes and thermal underwear), consumer goods, and medical devices. Its ability to be easily customized through copolymerization makes it suitable for a broad range of applications. For instance, food containers made from polypropylene are microwave safe, and its use in the automotive industry helps reduce vehicle weight, thereby improving fuel efficiency. Moreover, its resistance to water absorption and chemical solvents makes it an excellent choice for laboratory equipment and pipework systems.

Titanium is a lustrous transition metal known for its high strength, light weight, and excellent corrosion resistance. It is widely used in aerospace, medical implants, and marine environments. Its density is one of its most notable characteristics, making it particularly useful in applications where strength-to-weight ratio is critical. The density of titanium is approximately 4.506 g/cm³. This comparatively low density, when paired with its strong mechanical properties, makes titanium alloys highly valued in advanced engineering applications. Unlike denser metals such as steel or copper, titanium offers a unique combination of lightweight and robustness, contributing to its preference in designing fuel-efficient vehicles and high-performance aerospace components.

Yes, titanium dioxide is FDA approved for specific uses. It is commonly used as a color additive in drug, food, and cosmetic products marketed in the U.S. However, it's imperative to note that while the FDA approves its usage in regulated proportions, direct inhalation or exposure to titanium dioxide (for instance, in some workplace settings) might have health implications. Therefore, it is advised to handle this compound with necessary precautions.