Nano Titanium Dioxide

Nano Titanium Dioxide refers to titanium dioxide (TiO2) particles that range from 1 to 100 nanometers in size. Titanium dioxide nanoparticles are sometimes referred to as "ultrafine."

In Food

 * "A study by American, Swiss, and Norwegian researchers entitled Titanium Dioxide Nanoparticles in Food and Personal Care Products estimates and quantifies the human exposure resulting from nanoparticle sized titanium dioxide (TiO2) found in processed foods. The study measured nanoparticles in food-grade TiO2 and derived estimates of nano TiO2 in foods including M&M’s, Betty Crocker Whipped Cream Frosting, Jell-O Banana Cream Pudding, Mentos, Trident and Dentyne gums, Vanilla Milkshake Pop Tarts, and Nestlé Original Coffee Creamer. The authors state that “electron microscopy and stability testing of food-grade TiO2 […] suggests that approximately 36% of the particles are less than 100nm in at least one dimension.""

Further testing by the group As You Sow found nano-sized titanium dioxide in Dunkin' Donuts Powdered Cake Donuts and Hostess Donettes. Corporations selling foods with nanoparticles are not always aware of the use of nanotechnology in their products, as they may have been included in an ingredient by a supplier without their knowledge.

Safety
A 2006 study published in The Lancet found that "ultrafine titanium dioxide dust caused respiratory tract cancer in rats exposed by inhalation and intratracheal instillation." The study raised concerns for workers exposed to ultrafine titanium dioxide dust on the job.

Other safety concerns have been raised over the use of titanium dioxide nanoparticles in sunscreens and cosmetics:


 * "Kumazawa, et. al. in their study, "Effects of Titanium Ions and Particles on Neutrophil Function and Morphology" concluded that cytotoxicity (danger to the cell) was dependent on the particle size of titanium dioxide. The smaller the particle size, the more toxic it is... This conclusion is relevant to the consumer because of the cosmetics industry's increasing use of micronized pigments in sunscreens and colour cosmetics. Nanoparticles of titanium dioxide are used in sunscreens because they are colourless at that size and still absorb ultraviolet light. Many cosmetic companies are capitalizing on metal oxide nanoparticles. We have seen, however, that if titanium dioxide particles used to act as a sunscreen are small enough, they can penetrate the cells, leading to photocatalysis within the cell, causing DNA damage after exposure to sunlight (Powell, et. al. 1996) The fear is that this could lead to cancer in the skin. Studies with subjects who applied sunscreens with micronized titanium dioxide daily for 2-4 weeks showed that the skin can absorb microfine particles. These particles were seen in the percutaneous layers of the skin under UV light. Coarse or fine particles of titanium dioxide are safe and effective at deflecting and absorbing UV light, protecting the skin, but consumers should avoid using products with micronized mineral pigments, either in sunscreens or colour cosmetics."

Other studies of nano titanium dioxide have found:
 * Nanoparticles of metal oxides can cross the blood-brain barrier
 * Titanium dioxide nanoparticles induce DNA damage and genetic instability in mice.
 * At "relatively high concentrations (100 mg/ml), nano titanium dioxide caused cytotoxicity and inflammation in human cells. Anatase TiO2 was 100 times more toxic than rutile Ti02. (Ti02 produced in sizes below 10 nanometers is typically anatase, not rutile.)
 * "Inhaled nano TiO2 has been found to act like asbestos and silicone in that it accumulates in the lung and causes inflammation and can impact DNA proteins and cell membranes."

Related SourceWatch articles

 * Nanotechnology
 * Nanosilver
 * Nanotechnology in Food

External resources

 * European Commission, Commission Recommendation of XXX on the Definition of Nanomaterial, 2011, 5.

External articles

 * Andrew Behar, Danielle Fugere, and Michael Passoff," Slipping Through the Cracks: An Issue Brief on Nanomaterials in Food," As You Sow.
 * Alex Weir, Paul Westerhoff, Lars Fabricius, et al., “Titanium Dioxide Nanoparticles in Food and Personal Care Products,” Environmental Science & Technology 46, no. 4 (2012): 2242-2250.
 * H.S. Sharma, S. Hussain, J. Schlager, et al., “Influence of Nanoparticles on Blood-Brain Barrier Permeability and Brain Edema Formation in Rats,” Acta Neurochir Suppl. 106 (2010): 359-364.
 * Benedicte Trouiller, Ramune Reliene, Aya Westbrook, et al., “Titanium Dioxide Nanoparticles Induce DNA Damage and Genetic Instability In Vivo in Mice,” The American Association for Cancer Research 69 (2009): 22
 * Jiangxue Wang, Guoqian Zhou, Chunying Chen, et al., “Acute Toxicity and Biodistribution of Different Sized Titanium Dioxide Particles in Mice after Oral Administration,” Toxicology Letters 168, no. 2 (2007): 176-185.
 * Christie M. Sayes, Rajeev Wahi, Preetha A. Kurian, et al., “Correlating Nanoscale Titania Structure with Toxicity: A Cytotoxicity and Inflammatory Response Study with Human Dermal Fibroblasts and Human Lung Epithelial Cells,” Toxicological Sciences 92, no. 1 (2006): 174–85.
 * Thomas C. Long, Navid Saleh, Robert D. Tilton, et al., “Titanium Dioxide (P25) Produces Reactive Oxygen Species in Immortalized Brain Microglia (BV2): Implications for Nanoparticle Neurotoxicity,” Environmental Science and Technology 40, no. 14 (2006): 4346-4352.
 * Churg et. al., "Induction of Fibrogenic Mediators by Fine and Ultrafine Titanium Dioxide in Rat Tracheal Explants," The American Journal of Physiology, November 1999.
 * Praful U. Jani, David E. McCarthy, and Alexander T. Florence, “Titanium Dioxide (Rutile) Particle Uptake from the Rat GI Tract and Translocation to Systemic Organs after Oral Administration,” International Journal of Pharmaceutics 105, no. 2 (1994): 157–168.