ISO 400 oil grade refers to the viscosity grade of industrial lubricants as defined by the International Organization for Standardization (ISO) under their ISO 3448 viscosity classification system. The number 400 indicates the midpoint of the oil's kinematic viscosity measured in centistokes (cSt) at 40°C. Oils classified under ISO 400 are considered to have higher viscosity, making them suitable for applications requiring thick lubricants that can maintain protective films under high-load or high-temperature conditions. This grade of oil is commonly used in heavy machinery, gearboxes, and hydraulic systems where robust lubrication is essential for optimal performance and longevity of the equipment.

The density of polypropylene (PP) typically ranges from 0.895 to 0.92 g/cm³. This thermoplastic polymer is known for its versatility and is widely used in various applications due to its balance between workability and physical properties. The slight variation in density can be attributed to the different grades of polypropylene available, which are tailored for specific uses such as packaging, textiles, automotive components, and consumer products. The density plays a crucial role in determining the material's strength, durability, and how it interacts with other substances, making it a critical parameter for engineers and designers when selecting materials for a project.

Titanium dioxide TiO2 is typically deemed as safe for the environment. even at low concentrations. This versatile mineral is utilized in numerous everyday items such as sunscreens. paints. and food. However. substantial amounts of its release into the environment could pose a threat to aquatic life and plant species due to its photocatalytic capabilities that generate reactive oxygen species. Several studies have also indicated potential impacts on soil microbiology. Thus. while it is not classified as a major hazard. it is advisable to implement proper control measures to minimize any potential releases into the environment.