Titanium oxide (Ti3O)

63.866 g/mol

63.9428553 g/mol

234-833-8

White crystalline powder|Transparent, coated, dispersed and nanofluid forms

17.1 Ų

4.23 g/cu cm

1843 °C

2972 °C

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.|SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Wei C, ed; The Medical Clinics of North America 91 (5): xiii-xv (2007). This issue discusses nanoparticles, including nanotubes, and the field of nanomedicine.|Finnish Institute of Occupational Health; Nanoatlas of Selected Engineered Nanoparticles, p10 (2009).[Available from, as of September 26, 2013: http://www.ttl.fi/partner/nanosh/progress/Documents/nanosh_nanoatlas.pdf]

Respirators may be necessary when engineering and administrative controls do not adequately prevent exposures. Currently, there are no specific exposure limits for airborne exposures to engineered nanoparticles, although occupational exposure limits exist for larger particles of similar chemical composition. Preliminary evidence shows that for respirator filtration media, particulates as small as 2.5 nm in diameter are efficiently captured, in keeping with single fiber filtration theory. Although this evidence needs confirmation, it suggests that it is likely that NIOSH-certified respirators will be useful for protecting workers from nanoparticle inhalation when properly selected and fit tested as part of a complete respiratory protection program. /Nanoparticles/|Respirators should be considered if engineering and administrative controls do not control worker exposures to nanoparticles. The decision to use respirators should be based on professional judgment and an assessment of worker exposures and the health risks they pose. /Nanoparticles/|Efficient ultrafine particle control devices (e.g., soft x-ray enhanced electrostatic precipitation systems) may have applicability to nanoparticles control. HEPA filters may be effective, and validation of their effectiveness is currently being studied. /Nanoparticles/|Engineering controls such as source enclosure (ie, isolating the generation source from the worker) and local exhaust ventilation systems should be effective for capturing airborne nanoparticles. Current knowledge indicates that a well-designed exhaust ventilation system with a high-efficiency particulate air (HEPA) filter should effectively remove nanoparticles. /Nanoparticles/|For more Personal Protective Equipment (PPE) (Complete) data for TITANIUM OXIDE NANOPARTICLES (9 total), please visit the HSDB record page.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.|SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.|... The reactor cleanout operation was determined to be an uncontrolled source of engineered nanomaterial (ENM) emissions, apparently due to technicians brushing and scraping unwanted buildup from the inside of the reactor. ...By changing the existing reactor cleanout work practice (vigorously brushing and scraping in multiple directions ... to a more targeted brushing/scraping (toward the inlet of the local exhaust ventilation (LEV)), emissions (both number and mass concentrations) were dramatically reduced... /Nanoparticles/|Worker training should be part of any complete safety and health program. To reduce nanoparticle exposures, workers should learn how to safely handle nanoparticles, use personal protective equipment, handle work clothes, clean contaminated surfaces, and dispose of spilled nanoparticles. /Nanoparticles/|For more Preventive Measures (Complete) data for TITANIUM OXIDE NANOPARTICLES (6 total), please visit the HSDB record page.

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 15 mg/cu m. /Titanium dioxide; Total dust/

NIOSH recommends exposure limits of 2.4 mg/cu m for fine TiO2 and 0.3 mg/cu m for ultrafine (including engineered nanoscale) TiO2, as time-weighted average (TWA) concentrations for up to 10 hours per day during a 40-hour work week. NIOSH has determined that ultrafine TiO2 is a potential occupational carcinogen but that there are insufficient data at this time to classify fine TiO2 as a potential occupational carcinogen.

Electron microscopy and stability testing of food-grade TiO2 (E171) suggests that approximately 36% of the particles are less than 100 nm in at least one dimension(1) with a measurable percentage existing as titanium oxide nanoparticles. Food grade TiO2 is used in many household and consumer products that gets discharged in sewage that enters wastewater treatment plants(1). Personal care products such as toothpastes and select sunscreens were found to contain 1 to >10% titanium by weight while other cremes, shampoos, deodorants and shaving cremes contained much lower TiO2 levels of <0.01 ug Ti/mg(1). The US FDA regulates suncreens and cosmetics as over-the-counter drugs(1); the only FDA-stipulated limitation for sunscreens is that the TiO2 concentration be less than 25%(1). Titanium oxide nanoparticle concentration of sunscreens has been reported to vary from 2% to 15%(2).

/AQUATIC SPECIES/ This paper summarizes a comprehensive study on the 48-hr acute toxicity of water suspensions of six MNMs (ie, ZnO, TiO2, Al2O3, C60, SWCNTs, and MWCNTs) to Daphnia magna, using immobilization and mortality as toxicological endpoints. The results show that the acute toxicities of all MNMs tested are dose dependent. The EC50 values for immobilization ranged from 0.622 mg/L (ZnO NPs) to 114.357 mg/L (Al2O3 NPs), while the LC50 values for mortality ranged from 1.511 mg/L (ZnO NPs) to 162.392 mg/L (Al2O3 NPs). In these tests, TiO2, Al2O3, and carbon-based nanomaterials were more toxic than their bulk counterparts. Moreover, D. magna were found to ingest nanomaterials from the test solutions through feeding behaviors, which indicates that the potential ecotoxicities and environmental health effects of these MNMs cannot be neglected.|/AQUATIC SPECIES/ A semi-static test system was used to expose rainbow trout to either a freshwater control, 0.1, 0.5, or 1.0 mg/L TiO2 nanoparticles (NPs) for up to 14 days. Exposure to TiO2 NPs caused some gill pathologies including edema and thickening of the lamellae. No major hematological or blood disturbances were observed in terms of red and white blood cell counts, hematocrit values, whole blood hemoglobin, and plasma Na+ or K+ concentrations. Tissue metal levels (Na+, K+, Ca2+ and Mn) were generally unaffected. However, some exposure concentration-dependent changes in tissue Cu and Zn levels were observed, especially in the brain. Exposure to TiO2 NPs caused statistically significant decreases in Na+K+-ATPase activity (ANOVA, P < 0.05) in the gills and intestine, and a trend of decreasing enzyme activity in the brain (the latter was not statistically significant). Thiobarbituric acid reactive substances (TBARS) showed exposure concentration-dependent and statistically significant (ANOVA or Kruskal-Wallis test, P < 0.05) increases (two-fold or more) in the gill, intestine and brain, but not the liver during exposure to TiO2 NPs compared to controls. TiO2 NP exposure caused statistically significant (ANOVA, P < 0.05) increases in the total glutathione levels in the gills, but depletion of hepatic glutathione compared to controls. Total glutathione levels in the brain and intestine were unaffected. Liver cells exposed to TiO2 NPs showed minor fatty change and lipidosis, and some hepatocytes showed condensed nuclear bodies (apoptotic bodies). Fish probably ingested water containing TiO2 NPs during exposure (stress-induced drinking) which may have resulted in some areas of erosion on the intestinal epithelium. Overall we conclude that titanium dioxide nanoparticles are not a major ionoregulatory toxicant, or hemolytic, at the concentration and exposure times used. Respiratory distress is a concern and sub-lethal toxicity involves oxidative stress, organ pathologies, and the induction of anti-oxidant defences, such as glutathione.|/AQUATIC SPECIES/ ... Zebrafish, daphnids, and an algal species were used as models of various trophic levels and feeding strategies. To understand whether observed effects are caused by dissolution, particles were characterized before testing, and particle concentration and dissolution were determined during exposures. Organisms were exposed to silver, copper, aluminum, nickel, and cobalt as both nanoparticles and soluble salts as well as to titanium dioxide nanoparticles. ... Nanosilver and nanocopper cause toxicity in all organisms tested, with 48-hr median lethal concentrations as low as 40 and 60 ug/L, respectively, in Daphnia pulex adults, whereas titanium dioxide did not cause toxicity in any of the tests. Susceptibility to nanometal toxicity differed among species, with filter-feeding invertebrates being markedly more susceptible to nanometal exposure compared with larger organisms (ie, zebrafish). The role of dissolution in observed toxicity also varied, being minor for silver and copper but, apparently, accounting for most of the toxicity with nickel. Nanoparticulate forms of metals were less toxic than soluble forms based on mass added, but other dose metrics should be developed to accurately assess concentration-response relationships for nanoparticle exposures.|/AQUATIC SPECIES/ ...Titanium dioxide (TiO2) and fullerene (C60) nanoparticles /were prepared/ by filtration in tetrahydrofuran or by sonication. Daphnia magna were exposed to the four solutions using U.S. Environmental Protection Agency 48-hr acute toxicity tests. Images of the particle solutions were recorded using transmission-electron microscopy, and the median lethal concentration, lowest-observable-effect concentration, and no-observable-effect concentration were determined. Exposure to filtered C60 and filtered TiO2 caused an increase in mortality with an increase in concentration, whereas fullerenes show higher levels of toxicity at lower concentrations. Exposure to the sonicated solutions caused varied mortality. Understanding the potential impacts of nanoparticles will help to identify the most appropriate nanotechnology to preserve the aquatic environment while advancing medical and environmental technology.|For more Ecotoxicity Excerpts (Complete) data for TITANIUM OXIDE NANOPARTICLES (7 total), please visit the HSDB record page.

Titanium oxide nanoparticles may occur in feedstock ores, such as rutile, that are mined commercially for the production of TiO2(1).

Titanium oxide nanoparticles' production and use in water treatment facilities and a variety of consumer products such as sunscreen cremes and cosmetics(1,2) will result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: To date, the potential environmental effects of engineered nanoparticles in any quantity are largely unknown(1,2). The impact is linked to characteristics such as toxicity, bioavailability, mobility, stability, solubility and reactivity(1). It is not yet known whether natural soil microbial populations will be able to efficiently and adequately degrade nanoparticles(1). /Nanoparticles/|TERRESTRIAL FATE: Laboratory studies have shown that nano-TiO2 can be mobile in various soil conditions with potential movement to lower soil layers or groundwater(1). In general, large soil particles and low ionic strength conditions favor nano-TiO2 movement, while high clay content, dissolved organic carbon, and salinity conditions favor soil retention of nano-TiO2(1).|AQUATIC FATE: To date, the potential environmental effects of engineered nanoparticles in any quantity are largely unknown(1,2). The impact is linked to characteristics such as toxicity, bioavailability, mobility, stability, solubility and reactivity(1). /Nanoparticles/|AQUATIC FATE: Environmental fate modeling studies using the Rhine River predicted that nano-TiO2 concentrations in the water compartment would lie in the ng/L range while concentrations in the sediment would be in the mg/kg range(1); therefore, sediment is expected to be the main reservoir for the nanoparticles(1). BCF values of 1400 and 2100 were observed in carp exposed in respective nano-TiO2 concentrations of 10 and 3 mg/L(2). In contrast, no bioaccumulation was found in rainbow trout exposed to 1 mg/L(2). The contrasting results may be due varying test conditions (temperatures, water changing procedures), lower concentration exposures to rainbow trout, and carp feeding from bottom sediments where nano-TiO2 might accumulate(2). Although nano-TiO2 may bioaccumulate in fish, the uptake mechanism is not clear(2). The presence of UV and visible light often increase photocatalytic nano-TiO2 activity and toxicity(2); other environmental factors, such as pH, ionic strength, and presence of organic matter of the aquatic environment, could also affect nano-TiO2 behavior and effects(2). Behavior in water is also affected by agglomeration of nanoparticles to form larger clusters that may behave differently than individual particles.(2). These agglomerates would tend to behave differently in the environment than individual particles. Degree of agglomeration is affected by ionic strength and presence of organic matter in water(2).|For more Environmental Fate (Complete) data for TITANIUM OXIDE NANOPARTICLES (6 total), please visit the HSDB record page.

The presence of UV and visible light often increase photocatalytic nano-TiO2 activity and toxicity(1); other environmental factors, such as pH, ionic strength, and presence of organic matter of the aquatic environment, could also affect nano-TiO2 behavior and effects(1).

In studies using carp and nano-TiO2 (P25) with exposure periods of up to 25 days, the BCF values in the visceral organs were approximately 2100 at 3 mg/L, and approximately 1400 at 10 mg/L(1). In contrast, no bioaccumulation was observed in rainbow trout exposed to nano-TiO2 for 14 days(1). The contrasting results may be due to varying test conditions (temperatures, water changing procedures), lower concentration exposures to rainbow trout, and carp feeding from bottom sediments where nano-TiO2 might accumulate(1). Although nano-TiO2 may bioaccumulate in fish, the uptake mechanism is not clear(1).

Environmental fate modeling studies using the Rhine River predicted that nano-TiO2 concentrations in the water compartment would lie in the ng/L range while concentrations in the sediment would be in the mg/kg range(1); therefore, sediment is expected to be the main reservoir for the nanoparticles(1).|A study using soil samples from 11 different sites found that nano-TiO2 could remain suspended in soil suspensions for 10 days(1); furthermore, the calculated maximum travel distance for some soil samples was more than 30 cm, which suggested that nano-TiO2 might be transferred to deeper soil layers or even to ground water(1); in general, large soil particles and low ionic strength conditions favor nano-TiO2 movement, while high clay content, dissolved organic carbon, and salinity conditions favor soil retention of nano-TiO2(1).

SURFACE WATER: Nano-TiO2 was reported to have been detected in river water from Montana, but the source (natural or engineered) and the concentration of nano-TiO2 were not determined(1).

Foods that contain food-grade TiO2 include chewing gum, beverages, candy, baked goods, chocolate, various grain, dairy and sauce products, and various food additives(1); electron microscopy and stability testing of food-grade TiO2 suggests that approximately 36% of the particles are less than 100 nm in at least one dimension(1) with a measurable percentage existing as titanium oxide nanoparticles. Concentration of food-grade TiO2 in a variety of foods was found to vary from approximately 0.0005 to 3 ug Ti/mg food(1).

Occupational exposure to nanoparticles may occur through inhalation of dust and dermal contact with these compounds at workplaces where nanoparticles are produced or used. Use data indicate that the general population may be exposed to nanoparticles via dermal contact with consumer products products containing nanoparticles(1,2). Nanomaterials are currently incorporated into many consumer products, from tooth paste, bacteria-free socks to a swimsuit used in the 2008 Olympics(3). Due to the consequence of widespread usage and the supposed persistence against degradation, human and environmental exposure to nanomaterials are likely to increase(4). /Nanoparticles/|NIOSH is conducting research to determine whether nanoparticles pose a threat to exposed workers. No US or International exposure standards have been established. Workers can be exposed by unintentional hand-to-mouth transfer of materials or swallowing particles cleared from the respiratory tract(1). /Nanoparticles/|Occupational exposure to titanium oxide nanoparticles may occur through inhalation of dust and dermal contact with this compound at workplaces where titanium oxide nanoparticles are produced or used(1). The general population is exposed to titanium oxide nanoparticles through dermal contact with consumer products containing the compound, such as sunscreen, and through ingestion of foods and drinking water containing titanium oxide nanoparticles(1,2). The general population can also be exposed through inhalation via scenarios such as spray sunscreen products(1).

Other currently approved nanoparticle-containing products: Sunscreens (containing titanium dioxide and zinc oxide nanoparticles which make the product appear transparent)

Electron microscopy visualization and light microscopic investigations of three different application forms of titanium dioxide proved that neither surface characteristics, particle size nor shape of the micronized titanium dioxide result in any dermal absorption of this substance: Micronized titanium dioxide is solely deposited on the outermost surface of the stratum corneum and cannot be detected in deeper stratum corneum layers, the human epidermis and dermis.|There is increasing concern over the local and systemic side effects of TiO(2) and ZnO coated nanoparticles widely used in sun blockers. To determine the localization and possible skin penetration of TiO(2) and ZnO nanoparticles, dispersed in 3 sunscreen formulations, under realistic in vivo conditions in normal and altered skin. Nuclear microscopy techniques provided spatially resolved quantitative analysis of Ti and Zn nanoparticle distributions in transversal cryosections of skin obtained by biopsy with no further treatment. A test hydrophobic formulation containing coated 20-nm TiO(2) nanoparticles and 2 commercial sunscreen formulations containing TiO(2) alone or in combination with ZnO were tried, taking into account realistic use conditions by consumers and compared with the recommended standard condition for the sun protection factor test. The protocols consisted of an open test. Following a 2-hour exposure period of normal human skin to TiO(2)- and ZnO-containing sunscreens, detectable amounts of these physical blockers were only present at the skin surface and in the uppermost stratum corneum regions. Layers deeper than the stratum corneum were devoid of TiO(2) or exogenous ZnO, even after 48 hr of exposure to the sunscreen, under occlusion. Deposition of TiO(2) and ZnO nanoparticles in the openings of the pilosebaceous follicles was also observed, suggesting a preferential fixation area. Penetration of nanoparticles into viable skin tissue could not be detected. TiO(2) or ZnO nanoparticles are absent or their levels are too low to be tested under the stratum corneum in human viable epidermal layers. Therefore, significant penetration towards the underlying keratinocytes is unlikely.|The in vivo kinetics of nanoparticles is an essential to understand the hazard of nanoparticles. Here, the absorption, distribution, and excretion patterns of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles following oral administration were evaluated. Nanoparticles were orally administered to rats for 13 weeks (7 days/week). Samples of blood, tissues (liver, kidneys, spleen, and brain), urine, and feces were obtained at necropsy. The level of Ti or Zn in each sample was measured using inductively coupled plasma-mass spectrometry. TiO2 nanoparticles had extremely low absorption, while ZnO nanoparticles had higher absorption and a clear dose-response curve. Tissue distribution data showed that TiO2 nanoparticles were not significantly increased in sampled organs, even in the group receiving the highest dose (1041.5 mg/kg body weight). In contrast, Zn concentrations in the liver and kidney were significantly increased compared with the vehicle control. ZnO nanoparticles in the spleen and brain were minimally increased. Ti concentrations were not significantly increased in the urine, while Zn levels were significantly increased in the urine, again with a clear dose-response curve. Very high concentrations of Ti were detected in the feces, while much less Zn was detected in the feces. Compared with TiO2 nanoparticles, ZnO nanoparticles demonstrated higher absorption and more extensive organ distribution when administered orally. The higher absorption of ZnO than TiO2 nanoparticles might be due to the higher dissolution rate in acidic gastric fluid, although more thorough studies are needed.

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

/ALTERNATIVE and IN VITRO TESTS/ Osteosarcoma and chondrosarcoma are malignant bone tumors, and they significantly affect the life quality of patients including children and adults. The main treatment method is surgical amputation of the malignant lesion, despite that recurrence often occurs. Recently, it has been observed that TiO2 NPs killed HeLa cells effectively via photocatalysis in vitro, which indicates titanium dioxide (TiO2) nanoparticles (NPs) might be used to reduce the recurrence of osteosarcoma and chondrosarcoma by inducing cytotoxicity to bone tumor cells. In this study, we investigated the potential effects of TiO2 NPs in two cancer cell lines in vitro: U-2 OS (osteosarcoma) and SW 1353 (chondrosarcoma). We assessed cell viability, the levels of reactive oxygen species (ROS) and glutathione (GSH) after exposure to TiO2 NPs at different concentrations (0.1-100 ug/mL) for varying exposure periods (12-48 hours). Compared to the NP-free control, TiO2 NPs induced cell death in a dosage-dependent and time-dependent manner. The median inhibitory concentration (IC50) of TiO2 NPs at 24 hours was 211.3 +/- 15.2 ug/mL and 5408.8 +/- 45.9 ug/mL for SW 1353 and U-2 OS cell lines, respectively. TiO2 NPs concentrations above 1 ug/mL were more efficient to reduce the cell viability of SW 1353 than U-2 OS of NPs at all exposure times. The increased ROS and reduced GSH levels indicated that TiO2 NPs killed cancer cells through oxidative stress. These results suggested that the TiO2 NPs can be potentially used to minimize/prevent the recurrence of osteosarcoma and chondrosarcoma.|/ALTERNATIVE and IN VITRO TESTS/ Nanoparticles (NPs) are frequently applied in biomedical applications. The use of human mesenchymal stem cells (hMSC) in biomedicine is pivotal, especially in oncology and tissue engineering. Titanium dioxide (TiO2) and zinc oxide (ZnO) NPs are interesting agents in experimental oncology and stem cells are discussed to be a potential vehicle for NPs to tumor sites. However, little is known about hazardous effects of NPs in hMSC. The aim of the present study was to analyze functional impairment of hMSC by ZnO- and TiO2-NPs. Cytotoxic effects of NPs were evaluated by the MTT-assay. Furthermore, multi-differentiation capacity, spheroid formation and migration were assessed. The immunophenotype was observed by flow cytometry. Cytotoxic effects were observed at 625 nM ZnO-NPs whereas no cytotoxicity was seen in hMSC by TiO2-NPs. The differentiation capacity of hMSC into osteogenic and adipose lineages was unchanged. A long-term period cultivation of hMSC for 3 weeks after NP exposure revealed a persistence of NPs in the cytoplasm. The migration capability was impaired whereas the ability to form spheroids was not affected. Flow cytometric analysis revealed distinct alteration of cell surface markers CD 90 and CD 73. Major functional properties of hMSC were unaffected by TiO2- and ZnO-NPs. However, restricted migration might critically influence wound healing capacity. ...|/ALTERNATIVE and IN VITRO TESTS/ The effects of ingestion of engineered nanoparticles (NPs), especially via drinking water, are unknown. Using NPs spiked into synthetic water and cell culture media, /the researchers/ investigated cell death, oxidative stress, and inflammatory effects of silver (Ag), titanium dioxide (TiO2), and zinc oxide (ZnO) NPs on human intestinal Caco-2 and SW480 cells. ZnO NPs were cytotoxic to both cell lines, while Ag and TiO2 NPs were toxic only at 100 mg/L to Caco-2 and SW480, respectively. ZnO NPs led to significant cell death in synthetic freshwaters with 1 % phosphate-buffered saline in both cell lines, while Ag and TiO2 NPs in buffered water led to cell death in SW480 cells. NP exposures did not yield significant increased reactive oxygen species generation but all NP exposures led to increased IL-8 cytokine generation in both cell lines. These results indicate cell stress and cell death from NP exposures, with a varied response based on NP composition.|/ALTERNATIVE and IN VITRO TESTS/ Sunscreens containing ZnO and TiO(2) nanoparticles (NPs) are increasingly applied to skin over long time periods to reduce the risk of skin cancer. However, long-term toxicological studies of NPs are very sparse. The in vitro toxicity of ZnO and TiO(2) NPs on /human/ keratinocytes over short- and long-term applications is reported. The effects studied are intracellular formation of radicals, alterations in cell morphology, mitochondrial activity, and cell-cycle distribution. Cellular response depends on the type of NP, concentration, and exposure time. ZnO NPs have more pronounced adverse effects on keratinocytes than TiO(2). TiO(2) has no effect on cell viability up to 100 ug mL(-1), whereas ZnO reduces viability above 15 ug mL(-1) after short-term exposure. Prolonged exposure to ZnO NPs at 10 ug mL(-1) results in decreased mitochondrial activity, loss of normal cell morphology, and disturbances in cell-cycle distribution. From this point of view TiO(2) has no harmful effect. More nanotubular intercellular structures are observed in keratinocytes exposed to either type of NP than in untreated cells. This observation may indicate cellular transformation from normal to tumor cells due to NP treatment. Transmission electron microscopy images show NPs in vesicles within the cell cytoplasm, particularly in early and late endosomes and amphisomes. Contrary to insoluble TiO(2), partially soluble ZnO stimulates generation of reactive oxygen species to swamp the cell redox defense system thus initiating the death processes, seen also in cell-cycle distribution and fluorescence imaging. Long-term exposure to NPs has adverse effects on human keratinocytes in vitro, which indicates a potential health risk.|/OTHER TOXICITY INFORMATION/ This paper proposed a model-based approach to assess inhalation risk levels to manufacturing workers in titanium dioxide (TiO2) production factories. The risk level-based analytical schemes were present for investigations of job-related airborne nano/fine TiO2 dust exposures. A Hill model was used to reconstruct dose-response function based on data from rats exposed by chronic inhalation to poorly soluble fine and nanosized particles. A physiologically based lung model was used to predict surface area-based TiO2 burdens in alveolar surface and interstitial granuloma, respectively. The exposure effect was characterized by polymorphonuclear leukocytes (PMN) elevation effect on lung surface and lung tumor proportion on interstitium. Combining laboratory, field, and modeling results, two major findings were proposed to the current epidemiological studies: (i) the estimated median effective surface area-based TiO2 lung burden (EC50) for PMN elevation effect is 0.11 sq m/g lung (95% CI: 0.04-0.2) and EC50 for lung tumor proportion is 1.15sq m/g lung (95% CI: 0.65-1.89) and (ii) the estimates of risk curves are the pivotal results for public policy. The results demonstrate that packers in US factories have approximately 85.77 fold (95% CI: 63.84-94.33) of standard PMN counts of 10+6, whereas 86.97 fold (95% CI: 66.72-94.54) for surface treatment workers in EU factories at risk of 0.5. The lung had approximately 45% (95% CI: 15%-54%) tumor proportion for packers in US factories, whereas 48.19% (95% CI: 20-53.79%) for surface treatment workers in EU factories at risk of 0.5. The findings point out that dry/wet treatment and ore handlers in US and maintenance mechanics in EU factories were unlikely to pose substantial lung cancer risks.

Titanium oxide (Ti3O): ACTIVE|.. Can be engineered to function in ways that naturally occurring materials do not. Their large surface area per unit volume and enhanced chemical reactivity can be exploited in novel applications ... potential to transform sectors as diverse as medicine, manufacturing, energy, water supply and transportation... offer novel mechanisms for targeted delivery of drugs or of pesticides and fertilizers ... thereby reducing use of chemicals and materials. /Nanoparticles/|The challenge to achieve appropriate disinfection without forming harmful disinfection byproducts by conventional chemical disinfectants, as well as the growing demand for decentralized or point-of-use water treatment and recycling systems calls for new technologies for efficient disinfection and microbial control. Several natural and engineered nanomaterials have demonstrated strong antimicrobial properties through diverse mechanisms including photocatalytic production of reactive oxygen species that damage cell components and viruses (eg, TiO2, ZnO and fullerol), compromising the bacterial cell envelope (eg, peptides, chitosan, carboxyfullerene, carbon nanotubes, ZnO and silver nanoparticles (nAg)), interruption of energy transduction (eg, nAg and aqueous fullerene nanoparticles (nC(60))), and inhibition of enzyme activity and DNA synthesis (eg, chitosan). Although some nanomaterials have been used as antimicrobial agents in consumer products including home purification systems as antimicrobial agents, their potential for disinfection or microbial control in system level water treatment has not been carefully evaluated. This paper reviews the antimicrobial mechanisms of several nanoparticles, discusses their merits, limitations and applicability for water disinfection and biofouling control, and highlights research needs to utilize novel nanomaterials for water treatment applications.|Using a pulsed plasma process, nanometals ... are being produced. /Nano oxides and Metals/

... Personal exposure concentrations to fine (pigment-grade) and ultrafine (including engineered nanoscale) TiO2 should be determined with NIOSH Method 0600 using a standard 10-mm nylon cyclone or equivalent particle sizeselective sampler. Measurement results from NIOSH Method 0600 should provide a reasonable estimate of the exposure concentration to fine and ultrafine (including engineered nanoscale) TiO2 at the NIOSH RELs of 2.4 and 0.3 mg/cu m, respectively, when the predominant exposure to workers is TiO2.|Method: NIOSH 0600, Issue 3; Procedure: gravimetric (filter weight); Analyte: mass of respirable dust fraction; Matrix: air; Detection Limit: 0.03 mg per sample.|Table: Methods of Nanoparticle Characterization [Table#7389]