Titanium dioxide is a mineral substance that occurs naturally in the environment when titanium is oxidized. It is found as white crystals or as a powder. It may also be referred to as TiO2, titanium white (when used as a pigment), or titania.
Titanium dioxide has been classified by the International Agency for Research on Cancer (IARC) as Group 2B, possibly carcinogenic to humans. Inhalation exposure in rats caused an increased incidence of lung cancer. Although there were three epidemiological studies available to the IARC working group, all had methodological limitations and none found a significant association between occupational exposure and increased risk of cancer.
Additionally, titanium dioxide may reduce lung function in exposed workers, and cause pleural thickening and mild fibrotic changes. Other health effects include irritation of the eyes, skin and respiratory tract, as well as contact dermatitis and allergic sensitization.
Titanium dioxide was recently identified as an emerging priority for research on carcinogens due to its use in nanomaterials.
stel = short term exposure limit (15 min. maximum)
twa = time weighted average
imp = impinger (million particles per cubic foot, or mppcf)
g = gravimetric (mg/m3)
ACGIH = American Conference of Governmental Industrial Hygienists
TLV = threshold limit value (8 hour maximum)
Canadian Environmental Guidelines
Ontario Ambient Air Quality Criteria
24 hour: 34 µg/m3
Food Additives Permitted For Use
C – Colouring Agents
µg/m3 = micrograms per cubic metre
Titanium dioxide was not included in other Canadian government environmental guidelines reviewed.[22,23,24]
DSL – moderate priority substance with the greatest potential for exposure
PMRA list of formulants
List 4B: contains formulants which may be toxic, but will not adversely affect public health and the environment based on use patterns
DSL = domestic substances list
Titanium dioxide was not included in other Canadian government chemical listings reviewed.[27,28]
Titanium dioxide is used primarily as a white pigment in paints, vinyl compounds, enamels, plastics, specialty papers, inks, foods, toothpastes and cosmetics, and skin care products.[3,29] It is the most commonly used pigment worldwide, accounting for 70% of global volume of pigments produced. For optimum pigment properties, particle size is controlled within 0.2 to 0.4 micrometers.
Titanium dioxide is also used in sunscreens to protect skin from ultraviolet (UV) radiation. It is often used in nanoparticle size ranges, since small size increases scattering of UV radiation.
Titanium dioxide tends to be used in its ultrafine size range, which are nanoparticles measuring fewer than 100 nanometers. Nanomaterials have unique properties electronically, optically, mechanically, and chemically, which make them useful in a variety of industrial applications. However, the health and environmental effects of these particles are not well understood.
The toxicity of nanomaterials often differs compared to the same compound in a larger size fraction. For example, the two distinct crystalline forms of titanium dioxide (anatase and rutile), differ significantly in toxicity (anatase is 100 times more cytotoxic than rutile).
Ultrafine titanium dioxide has different shapes, sizes, and crystalline structures depending on how it's being applied. The nanoparticles of titanium dioxide can exist in shapes such as spheres, rods, wires, and agglomerates, and they can be coated with other chemicals, such as alumina.
Canadian Production & amp; Trade
Canada's capacity to produce titanium dioxide was over 100,000 tonnes in 2015, and between the years of 2011 and 2014, Canada provided 37% of the titanium dioxide used in the United States.
QIT-Fer et Titane operates an ilmenite mine (called Tio) located near Havre-Saint-Pierre, Quebec. QIT also operates a metallurgical complex to process the ilmenite ore into titanium slag in nearby Tracy, Quebec.
Production and Trade
3,656 t of 'titanium oxides'
4,634 t of 'titanium oxides'
t = tonne
Inhalation and dermal absorption are the most important routes of occupational exposure to titanium dioxide.
The main occupations exposed include workers at titanium mines, titanium dioxide production (particularly milling and packaging), as well as site cleaning and maintenance. The primary concern for exposure to titanium dioxide is inhalation; titanium dioxide found in powder or dust form can be aerosolized leading to increased exposure risk. If bound in another product, exposures are expected to be low.
CAREX Canada has not prioritized titanium dioxide for exposure estimate development. This is because there is a lack of exposure monitoring data in the Canadian Workplace Exposure Database on which to base an estimate.
Titanium dioxide is the most common form of titanium, which is the ninth most abundant element in the earth's crust. The main source of environmental exposure to titanium dioxide is dermal absorption from sunscreens, cosmetics, paints, and enamels; ingestion is also a potential source via these same products. Although most Canadians will be exposed to titanium dioxide via sunscreen, dermal absorption is not expected to carry the same risk as inhalation exposures. Populations living in close proximity to titanium mines and industrial plants may be at higher risk of exposure.
Titanium dioxide is not reportable to Environment Canada's National Pollutant Release Inventory.
A search of the US Household Products Database yielded the following results on current potential for exposure to titanium dioxide in Canada:
US Household Products Database
US Household Products 2015
Results: > 2,380 products
Paint, make-up, caulking, sunscreens, toothpastes
Our team has performed a detailed scan of exposure control resources and assembled a compilation of key publications and resources. These are organized by type of exposure (environmental or occupational) and by specificity (general or carcinogen-specific). Please visit our Exposures Reduction Resources page to view.
We also recommend exploring the Prevention Policies Directory, a freely-accessible online tool offering information on policies related to cancer and chronic disease prevention. Providing summaries of the policies and direct access to the policy documents, the Directory allows users to search by carcinogen, risk factor, jurisdiction, geographical location, and document type. To learn more about policies specific to titanium dioxide on the Directory, click here. For questions about this resource, please contact a member of the Prevention Team at the Canadian Partnership Against Cancer at firstname.lastname@example.org.