Hebei Hankai hydraulic wiper

Applications of the 50x65x8 Oil Seal

4. Unusual Noises Sounds such as grinding or hissing during operation can point to issues with seals, valves, or other components.

3. Pressure Management Oil seals can withstand varying pressure levels within machinery, contributing to the overall stability and performance of systems. They help maintain necessary pressure differentials in hydraulic systems, ensuring consistent operation.

The FDA first approved the use of titanium dioxide in food in 1966, following its 1960 removal (along with the removal of other color additives) from the agency's original Generally Recognized as Safe list. In 1977, titanium dioxide joined the list of color additives that are exempt from certification, which means titanium dioxide doesn't have to be listed on the packaging of every product it's used in, Faber noted.

This work was supported by SECyT-UNC Consolidar tipo I [2018-2021] and FONCyT, Argentina [grant number 0821-2014]. MVV holded a EVC-CIN scholarship from SECyT UNC. AM, MFPP AND MFC hold CONICET, FONCyT and SECyT scholarships respectively, and MJS, AZ, VA, MFP and MCB are career members of CONICET.

The assessment was conducted following a rigorous methodology and taking into consideration many thousands of studies that have become available since EFSA’s previous assessment in 2016, including new scientific evidence and data on nanoparticles. 

A review published in 2022 in the journal NanoImpact evaluated the latest research related to genotoxic effects of titanium dioxide through in vivo studies and in vitro cell tests. Researchers summarized the results by stating TiO2 nanoparticles “could induce genotoxicity prior to cytotoxicity,” and “are likely to be genotoxic to humans.”

Different dermal cell types have been reported to differ in their sensitivity to nano-sized TiO₂ . Kiss et al. exposed human keratinocytes (HaCaT), human dermal fibroblast cells, sebaceous gland cells (SZ95) and primary human melanocytes to 9 nm-sized TiO₂ particles at concentrations from 0.15 to 15 μg/cm² for up to 4 days. The particles were detected in the cytoplasm and perinuclear region in fibroblasts and melanocytes, but not in kerati-nocytes or sebaceous cells. The uptake was associated with an increase in the intracellular Ca²⁺ concentration. A dose- and time-dependent decrease in cell proliferation was evident in all cell types, whereas in fibroblasts an increase in cell death via apoptosis has also been observed. Anatase TiO₂ in 20–100 nm-sized form has been shown to be cytotoxic in mouse L929 fibroblasts. The decrease in cell viability was associated with an increase in the production of ROS and the depletion of glutathione. The particles were internalized and detected within lysosomes. In human keratinocytes exposed for 24 h to non-illuminated, 7 nm-sized anatase TiO_2, a cluster analysis of the gene expression revealed that genes involved in the “inflammatory response” and “cell adhesion”, but not those involved in “oxidative stress” and “apoptosis”, were up-regulated. The results suggest that non-illuminated TiO₂ particles have no significant impact on ROS-associated oxidative damage, but affect the cell-matrix adhesion in keratinocytes in extracellular matrix remodelling. In human keratinocytes, Kocbek et al. investigated the adverse effects of 25 nm-sized anatase TiO₂ (5 and 10 μg/ml) after 3 months of exposure and found no changes in the cell growth and morphology, mitochondrial function and cell cycle distribution. The only change was a larger number of nanotubular intracellular connections in TiO₂-exposed cells compared to non-exposed cells. Although the authors proposed that this change may indicate a cellular transformation, the significance of this finding is not clear. On the other hand, Dunford et al. studied the genotoxicity of UV-irradiated TiO₂ extracted from sunscreen lotions, and reported severe damage to plasmid and nuclear DNA in human fibroblasts. Manitol (antioxidant) prevented DNA damage, implying that the genotoxicity was mediated by ROS.