Titanium dioxide TiO2 nanoparticles are frequently utilized in the cosmetic and pharmaceutical fields. but may have harmful effects on DNA in specific circumstances. This is typically linked to the production of reactive oxygen species ROS during exposure. which can result in oxidative stress and genetic mutations. These factors can potentially heighten the risk of cancer and other illnesses. As a result. proper handling and usage of TiO2 nanoparticles is crucial. particularly within the realms of cosmetics and pharmaceuticals.

Phthalates are chemical compounds mainly used as plasticizers, substances added to plastics to increase their flexibility, transparency, durability, and longevity. They are most commonly associated with polyvinyl chloride (PVC) rather than polypropylene (PP). Polypropylene is a type of plastic marked by the recycling symbol #5 and is known for not requiring plasticizers to achieve its desired properties. Consequently, PP is generally considered to be free from phthalates. It's worth noting, however, that contamination during manufacturing or recycling processes can't be entirely ruled out, but such occurrences are exceptions rather than the norm. Therefore, while not inherently present, consumers seeking absolute assurance should look for products specifically labeled as phthalate-free.

The coefficient of friction (COF) between polyurethane and polypropylene is not a fixed value and can vary depending on factors such as the specific formulation of the polymers, the presence of additives, surface roughness, and the conditions under which the measurement is made (e.g., dry vs. lubricated). Generally, polyurethane can exhibit a wide range of COF due to its versatility and ability to be formulated as both soft and hard material. Polypropylene typically exhibits a lower coefficient of friction, being a semi-crystalline thermoplastic with a smooth surface. However, roughening the surface of polypropylene can increase its COF. In applications where the friction between these materials is critical, testing under the specific conditions of use is recommended to obtain an accurate measurement. This will ensure the functionality and longevity of the components in their intended application.