Hebei Hankai defender rear hub seal

Finally, the 7% relates to the material composition and the durability of the seals. Oil seals are typically constructed from various compounds, including elastomers and polyurethane, each tailored for specific environmental conditions. A 7% threshold can indicate the percentage of material degradation that is acceptable over a defined lifespan. High-quality seals are engineered to endure extreme pressures and environmental challenges, maintaining their integrity even as their material composition undergoes wear.

Recent analyses of food-grade TiO₂ samples have found that a significant portion of particles may be within the nanoscale. These particles (also known as nanoparticles) range in size from 1 to 100 nm, where 1 nm equals 1 billionth of a metre (the width of a typical human hair is 80,000 to 100,000 nm).

Though the regulated use of titanium dioxide in food products is legal in the U.S. and Canada, it's banned in some other countries, notably throughout Europe. In May 2021, the European Food Safety Authority announced that titanium dioxide can no longer be considered safe as a food additive.

Our scientific experts applied for the first time the 2018 EFSA Scientific Committee Guidance on Nanotechnology to the safety assessment of food additives. Titanium dioxide E 171 contains at most 50% of particles in the nano range (i.e. less than 100 nanometres) to which consumers may be exposed.