Titanium Dioxide: Toxic or Safe?

Titanium dioxide is the subject of new controversy, yet it is a substance as old as the earth itself. It is one of the top fifty chemicals produced worldwide. It is a white, opaque and naturally- occurring mineral found in two main forms: rutile and anatase. Both forms contain pure titanium dioxide that is bound to impurities. Titanium dioxide is chemically processed to remove these impurities, leaving the pure, white pigment available for use. Titanium dioxide has a variety of uses, as it is odorless and absorbent. This mineral can be found in many products, ranging from paint to food to cosmetics. In cosmetics, it serves several purposes. It is a white pigment, an opacifier and a sunscreen. Concern has arisen from studies that have pointed to titanium dioxide as a carcinogen and photocatalyst, thus creating fear in consumers. But are these claims true? What does the research on these allegations bear out? Would we as consumers benefit from avoiding this mineral to preserve our long-term health?

A carcinogen is a substance that causes a cellular malfunction, causing the cell to become cancerous and thus potentially lethal to the surrounding tissue and ultimately the body as these rapidly growing mutated cells take over. With the surge in cancer rates among all segments of the population, many people are attempting to reduce or eliminate their exposure to carcinogens. Titanium dioxide is regarded as an inert, non-toxic substance by many regulatory bodies such as the MSDS (Material Safety Data Sheets) and others charged with the responsibility of safeguarding the health of occupational workers and public health. The MSDS states that titanium dioxide can cause some lung fibrosis at fifty times the nuisance dust, defined by the US Department of Labor as 15 mg/m cubed (OSHA) or 10 mg/m cubed (ACGIH Threshold Limit Value). The ACGIH states that titanium dioxide is “not classifiable as a human carcinogen”. Symptoms of chronic overexposure to titanium dioxide in an industrial setting, according to the MSDS, include a “slight increase in lung tumour incidence in lab rats”. It also states “when titanium dioxide was fed to rats/mice in a carcinogen bioassay, it was not carcinogenic”. The NIOSH declares that at 5000 mg/m cubed there was slight lung fibrosis, concluding that this substance was carcinogenic in rats.

The NIOSH declaration of carcinogenicity in rats is based on a study by Lee, Trochimowicz & Reinhardt, “Pulmonary Response of Rats Exposed to Titanium Dioxide by Inhalation for Two Years” (1985). The authors of this study found that rats chronically exposed to excessive dust loading of 250 mg/m cubed and impaired clearance mechanisms within the rat, for six hours per day, five days per week for two years, developed slight lung tumours. They also noted that the biological relevance of this data to lung tumours in humans is negligible. It is important to note that rats are known to be an extremely sensitive species for developing tumours in the lungs when overloaded with poorly soluble, low toxicity dust particles. Rat lungs process particles very differently compared to larger mammals such as dogs, primates or humans (Warheit, 2004). This sensitivity in the lungs has not been observed in other rodent species such as mice or hamsters (Warheit, 2004), therefore using the rat model to determine carcinogenicity of titanium dioxide in humans can be misleading, as extrapolation of species-specific data to humans is erroneous.

Many organizations and businesses have perpetuated this assessment of the carcinogenicity of titanium dioxide (ewg.org). However, several studies and study reviews have been used to compile the safety disclaimers for the regulations on the permitted use of titanium dioxide. One such study review took place in Rome, 1969 between the World Health Organization and the Food & Agriculture Organization of the United Nations. Cross species analyses were performed and reviewed for possible toxicity of titanium dioxide. The conference concluded that among the following species: rats, dogs, guinea pigs, rabbits, cats and human males, ingestion of titanium dioxide at varying diet percentages and over long periods of time did not cause absorption of this mineral. Titanium dioxide particulates were not detected in the blood, liver, kidney or urine and no adverse effects were noted from its ingestion. The U.S. Food & Drug Administration (2002) allows for its ingestion, external application including the eye area, and considers it a safe substance for public health. Other epidemiological studies showed that workers exposed to titanium dioxide exhibited no statistically significant relationship between such exposure with lung cancer and respiratory disease, although some cases of pulmonary fibrosis did occur. These studies were conducted in industrial settings where the increased exposure puts these individuals more at risk than the average person.

Titanium dioxide is listed as a safe pigment, with no known adverse effects. It is not listed as a carcinogen, mutagen, teratogen, comedogen, toxin or as a trigger for contact dermatitis in any other safety regulatory publications beside the NIOSH (Antczak, 2001; Physical & Theoretical Chemical Laboratory, Oxford University respectively). It is reasonable to conclude then, that titanium dioxide is not a cancer-causing substance and is generally safe for use in foods, drugs, paints and cosmetics. This does not end the debate, however, as controversy over the safety of one unique form of titanium dioxide still exists.

One form of mineral or mineral extract, including titanium dioxide, that we should be concerned about is ultrafine or nano particles. As technology has advanced, so has its ability to take normal sized particles of minerals and reduce them to sizes never before imagined. While many are praising this new technology, others are warning of its inherent dangers to our bodies. A study by Churg et. al. at the University of British Columbia in their paper “Induction of Fibrogenic Mediators by Fine and Ultrafine Titanium Dioxide in Rat Tracheal Explants” (1999) found that ultrafine particles of the anatase form of titanium dioxide, which are less than 0.1 microns, are pathogenic or disease causing (see Table 1).

Table 1: Measurements of Mineral Pigment Particles

Particle Size | Measurement
Coarse | Less than 10 microns
Fine | Less than 2.5 microns
Ultrafine (nanoparticles) | Less than 0.1 microns or 100 nanometres

-etcgroup.org

Table 2: Particle Size and Entry into the Human Body

Nanoparticle Size | Entry Point
70 nanometres | Alveolar surface of lung
50 nanometres | Cells
30 nanometres | Central Nervous System
Less than 20 nanometres | No data yet

-etcgroup.org

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 (see Table 2). 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.

As with any health issue, relevant studies must be examined closely to reach balanced conclusions about its impact on our health and well-being. Often, risk determinations are made without considering actual hazards and real-life exposures (Warheit, 2004). The Organic Make-up Co. considers fine or coarse particle sized titanium dioxide and other mineral pigments to be safe according to the studies available and information discussed in this article. Despite repeated requests for micronized pigments in our colour cosmetics, we insist on using only coarse or fine particles of mineral pigments, balancing our need to look beautiful with our more pressing need to stay healthy. With the multitude of cosmetics and chemicals available to us, it is in our best interest to become informed as consumers and make pure, natural and simple choices to protect our health and longevity.

References:

– Antczak, Cosmetics Unmasked. Harper Collins; London:2001

– Blake, et.al. “Application of the Photocatalytic Chemistry of TiO2 to Disinfection and the Killing of Cancer Cells”, Separation and Purification Methods; Vol 28 (1) 1999 p.1-50

– Churg, Gilks, Dai, UBC Dept. of Pathology. Am J Physiol Lung Cell Mol Physiol. Vol 277 Issue 5 L975-L982, 1999

– Dunford, et. al. FEBS Letters 418, 87 1997

– Etcgroup.org

– Kamazawa, et.al. “Effects of Titanium Ions and Particles of Neutrophil Function and Morphology”. Biomaterials 2002 Sep 23 (17): 3757-64

– Powell, et. al. GUT 38, 390 1996

– Warheit, David “Nanoparticles: Health Impacts?”. Materials Today, Feb. 2004

– Witt, Stephen. Director of Technological Support, N. American Refractories Co.

 

Titanium’s Superhero Qualities of Strength, Resistance, and Durability

Titanium is most certainly a superhero of a metal. It is highly resistant to corrosion. It is lighter than steel, heavier than aluminum, and stronger than both of those metals. While it is more expensive to invest in initially, titanium is cheaper over the long run. This is because there is no service, maintenance, or repairs needed. What causes titanium to be so… heroic?

Discovered in 1793 by German chemist M.H. Klaproth, titanium was named after the Titans in Greek mythology since they are the incarnation of natural strength. The element was not isolated until 1910. Titanium is the ninth most abundant element on the planet as it makes up 25% of the earth’s crust. It occurs in nature only in chemical combinations of oxygen and iron.

Titanium is has high passivity. This allows it to have corrosion resistance to many minerals and chlorides. Titanium is very useful in the medical field because of its non-toxicity. It is also biologically compatible human bone and tissue. Titanium is commonly found in medical implantation products and prosthetics.

Titanium is produced first with Australian beach sand. The sand is formed into titanium-containing rutile-ore and chlorinated into a sponge. Chlorine and coke are combined with rutile to produce titanium tetrachloride.

Tetrachloride is reacted to magnesium in a closed system, making the byproducts sponge and magnesium chloride. The magnesium and mag chloride can be removed using the Vacuum Distillation Process to be reused again.

The sponge is melted with scrap and alloying elements. This can include vanadium, zirconium, tin, aluminum, and molybdenum. This is performed in a Vacuum Arc Reduction furnace to produce VAR ingots. It can also be done in an Electron Beam Cold Hearth furnace to produce remote electrodes. They can be VAR melted to meet aerospace requirements, or to direct slabs.

VAR ingots are cylindrical shapes weighing up to 17,500 pounds. The ingots are forged into slabs, or rectangular shapes. They can also be forged into billets, or bar shapes. Ingots can be used for investment casting stock as well.

Further processing or rolling of forged or cast slab or billet result in mill products. These include titanium plates, bars, rods, and titanium wire forms. Production can also create sheets of titanium that can be cut into strips. These strips are then formed into tubes or pipes.

There are many different grades of titanium to be used for different purposes. Grade 1 is one of the four commercially pure titanium grades, along with grades 3 through 4. Grade 1 is soft and the most ductile. It has great formability, toughness, and high corrosion resistance. Grade 1 is available in titanium plate and tubing.

Grade 2 is the workhorse because of its varied usability and availability. It is similar to grade 1 but stronger. Grade 2 has good weldability, strength, ductility, and formability. Grade 2 is available in bar and sheet form.

Grade 3 is the least used, but is stronger than grades 1 and 2. It is less formable but has higher mechanicals. Application of grade 3 is used when strength and major corrosion resistance is needed. Grade 4 is the strongest and has all the traits of previous grades. When high strength is needed, grade 4 is used.

One of the most amazing things about titanium is its use in the medical world. Titanium is used for joint reconstruction. The natural properties in titanium, such as being non-toxic and biologically compatible, make it perfect for body part reconstruction.

Titanium is truly a superhero amongst the different kinds of metals. Its strength, durability, low maintenance requirements, and corrosion resistance make it a popular and useful metal. The formation and grades of titanium show how many applications and uses the metal holds.

Medicine Has Revolutionized Uses for the Titanium Rod

Titanium rods can be composed of pure titanium or a mixture of pure titanium and other alloys. Rods are commonly used in medicine as bone replacements, especially in orthopedic surgeries. There are many great natural properties titanium has that make it perfect for medicinal uses.

Titanium has high strength but is very lightweight. The metal is also non toxic and extremely resistant to corrosion. The various corrosive body fluids cannot do any damage to the metal. Titanium is durable and long-lasting with the ability to stay in the body for up to 20 years.

Titanium is lighter than steel, heavier than aluminum, and stronger than both of those metals. While it is more expensive to invest in initially, titanium is cheaper over the long run. This is because there is no service, maintenance, or repairs needed.

Titanium is has high passivity. This allows it to have corrosion resistance to many minerals and chlorides. Titanium is very useful in the medical field because of its non-toxicity. It is also biologically compatible human bone and tissue.

The non-ferromagnetic property of titanium is a huge benefit for medicine. Patients who have titanium rods can be safely examined with MRIs and NMRIs. Most often, titanium is used for reconstructing certain parts of the body.

Failing sockets, joints, or severely broken bones can be replaced with titanium implants. Titanium produces medical pins, rods, bone plates, screws, bars, wires, posts, expandable rib cages, spinal fusion cages, finger and toe replacements, and maxio-facial prosthetics.

Surgically, titanium is one of the perfect resources to use when making instruments. Titanium is harder than steel but more lightweight. It is resistant to bacteria and infection. It can be used with medical instruments that emit radiation. Titanium is also durable and long-lasting. An investment in titanium surgical instruments would pay off extremely well.

The ends of titanium rods can be threaded or hooked. This depends on what the patient needs surgically. Titanium has a natural and wondrous process called osseointegration. Osseointegration is the term used when the bone and tissue in the human body bond to the titanium implant. This phenomenon locks the implant into place permanently.

The specific titanium rod that is used for medicine depends on injuries and how stable or flexible the rod must be. Replacing a bone in the leg, for example, requires titanium alloys. This makes the rod stiff and supportive, like how a bone is naturally. Pure titanium is more flexible and is used when the rod must be formed into a certain shape before implantation.

Most patients receive titanium alloy rods. There is a high friction rate associated with titanium alloy rods, meaning any rubbing against another titanium rod must be avoided. For children who need orthopedic surgery, an expanding titanium rod is used.

This rod is attached to the joints and osseointegration occurs. The rod will grow with the bone as the child grows. Expanding titanium rods can only be used to replace large bones in the body, such as a leg bone. Expanding rods reduce the occurrence of more surgeries since the rod will be able to grow with the child. Expanding rods are generally used as much as possible

However, non-expanding rods are also necessary. Non-expanding rods used in surgeries where the person is still growing means that multiple surgeries will be needed to continually replace the rod. If the rod is not replaced as growing continues, it can stunt a child’s growth since the rod will prevent the body from naturally growing.

Since its widespread production in the 1940s, there have been widespread improvements in the process and production technology, alloy development, measurement of properties and characteristics, and the development of applications throughout many industries. The constant drive to higher efficiencies is part of the reason more medical uses are being found for titanium.

Why You Should Consider Buying Titanium Glasses

If you need to buy a pair of eyeglasses these days, why should you even think about buying titanium glasses? Titanium frames are known for their rather exorbitant prices, and in these times of economic distress, paying high prices for something you need could be considered an extravagance, especially if there are less expensive alternatives.

However, the many benefits of titanium frames dispel the notion that they are merely luxury items. The advantages of titanium over traditional frame materials may cause you to reconsider your reluctance, and you would actually come to realise that titanium frames may be prove to be not just worth the high price but also prove to be far more cost-effective in the long run.

The Durability of Titanium

Titanium has long been known for its association with space rockets, and for good reason. Many vehicles that were designed for space travel were built primarily with titanium. Due to recent developments in metal technology, titanium can now be used for something as ordinary and commonplace as eyewear, as if titanium glasses can ever be called ordinary in the first place.

Titanium frames will last you a very long time. Part of the reason for this is that titanium bends more easily than other metals. This means that a titanium frame will bend to pressure rather than snap, as other frames are wont to do. Snapped eyeglasses parts (such as arms) are among the most common kinds of damage to eyewear, but with titanium this can be considerably minimised.

Titanium is also very resistant to corrosion. People who tend to wear glasses in very humid locations tend to find their glasses exhibiting signs of rust after a while, and this is especially true for those who wear them near pools. With titanium frames, this becomes less of a concern.

Low Maintenance

As part of its durability, it requires very little maintenance on your part to keep it in good condition. You only need to keep them in their case when not in use, and that will ensure that they keep their shape. If they have bent at an odd angle (which is much better than snapping in two or more pieces), you can set them back in place with a pair of pliers and the exertion of very, very, gentle pressure.

With a pair of titanium spectacles, your visits to the optical shop can be greatly reduced. This saves you a lot of effort, and also money.

Additional Advantages

Titanium as a frame material causes far less skin reactions, which can be quite beneficial for those with allergies. It is also very lightweight, which can prevent the onset of headaches and migraines due to constant use of prescription glasses. People who need to wear very thick lenses may also find the lightness of the titanium frame an utter joy to wear.

As a final note, there are now many reliable online sellers of titanium spectacles that offer far more attractive prices than ever before. By eliminating the need to set up a brick and mortar shop, these sellers are able to offer them for a lot less. Titanium glasses may be expensive, but if you know where to look online they may not be as pricey as you think.