Titanium Dioxide Profile

Titanium Dioxide Profile

General Information

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.[1] It may also be referred to as TiO2, titanium white (when used as a pigment), or titania.[1]

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.[2] 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.[2]

Additionally, titanium dioxide may reduce lung function in exposed workers, and cause pleural thickening and mild fibrotic changes.[2] Other health effects include irritation of the eyes, skin and respiratory tract, as well as contact dermatitis and allergic sensitization.[1]

Titanium dioxide was recently identified as an emerging priority for research on carcinogens due to its use in nanomaterials.[3]

Regulations and Guidelines

Occupational Exposure Limits (OEL) [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]

Canadian Jurisdictions OEL (mg/m3)
Canada Labour Code 10
AB, MB, NL, NS, ON, PE 10
BC 10 [t]; 3 [r]
NB, QC 10 [t]
NT, NU, SK 10
20 [stel]
YT 30 [twa, imp]; 10 [twa, g]
Other Jurisdictions OEL (mg/m3)
ACGIH 2018 TLV 10
mg/m3 = milligrams per cubic metre
t = total dust
r = respirable fraction
tm = total mass
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

Jurisdiction Limit Year
Ontario Ambient Air Quality Criteria 24 hour: 34 µg/m3 2016[19]
Food Additives Permitted For Use C – Colouring Agents 2017[20]
µg/m3 = micrograms per cubic metre

Titanium dioxide was not included in other Canadian government environmental guidelines reviewed.[21,22,23]

Canadian Agencies/Organizations

Agency Designation/Position Year
Health Canada DSL – moderate priority substance with the greatest potential for exposure 2006[24]
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 2018[25]
DSL = domestic substances list

Titanium dioxide was not included in other Canadian government chemical listings reviewed.[26,27]

Main Uses

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.[2,28] It is the most commonly used pigment worldwide, accounting for 70% of global volume of pigments produced.[28] For optimum pigment properties, particle size is controlled within 0.2 to 0.4 micrometers.[29]

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.[29]

Nanoparticles

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.[30]

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).[30]

Ultrafine titanium dioxide has different shapes, sizes, and crystalline structures depending on how it’s being applied.[30] 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.[30]

Canadian Production and 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.[29]

QIT-Fer et Titane operates an ilmenite mine (called Tio) located near Havre-Saint-Pierre, Quebec.[31] QIT also operates a metallurgical complex to process the ilmenite ore into titanium slag in nearby Tracy, Quebec.[31]

Production and Trade

Activity Quantity Year
Export 3,656 t of ‘titanium oxides’ 2015[32]
Import 4,634 t of ‘titanium oxides’  
t = tonne

Environmental Exposures Overview

Titanium dioxide is the most common form of titanium, which is the ninth most abundant element in the earth’s crust.[33] 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.[2] Although most Canadians will be exposed to titanium dioxide via sunscreen, dermal absorption is not expected to carry the same risk as inhalation exposures.[1] 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.[34]

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[35]
Results: > 2,380 products
Search Term Quantity Product Type
‘titanium dioxide’ 2,380 Paint, make-up, caulking, sunscreens, toothpastes

Occupational Exposures

Inhalation and dermal absorption are the most important routes of occupational exposure to titanium dioxide.[1]

The main occupations exposed include workers at titanium mines, titanium dioxide production (particularly milling and packaging), as well as site cleaning and maintenance.[2] 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.[2]

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.

Sources

1. Toxicology Data Network (TOXNET). Hazardous Substances Data Bank (Search term: ‘Titanium dioxide’)
2. International Agency for Research on Cancer (IARC). Monograph summary Volume 93 (2010) (PDF)
3. Ward EM, Schulte PA, Straif K, Hopf NB, Caldwell JC, Carreón T, DeMarini DM, Fowler BA, Goldstein BD, Hemminki K, Hines CJ, Pursiainen KH, Kuempel E, Lewtas J, Lunn RM, Lynge E, McElvenny DM, Muhle H, Nakajima T, Robertson LW, Rothman N, Ruder AM, Schubauer-Berigan MK, Siemiatycki J, Silverman D, Smith MT, Sorahan T, Steenland K, Stevens RG, Vineis P, Zahm SH, Zeise L, Cogliano VJ.“Research Recommendations for Selected IARC-Classified Agents.” Environ Health Perspect2010;118(10):1355-1362.
4. Occupational Safety and Health Administration (OSHA). Annotated PELs (2018)
9. Government of Newfoundland and Labrador. Regulation 5,12 Occupational Health and Safety Regulations (2012)
10. Government of the Northwest Territories. Occupational Health and Safety Regulations, R-039-2015 (2016) (PDF)
12. The Canadian Legal Information Institute (CanLII). Government of Nunavut’s Occupational Health and Safety Regulations, Nu Reg 003-2016 (2010)
15. Government of Prince Edward Island. Occupational Health and Safety Act Regulations Chapter 0-1 (2013) (PDF)
17. Government of Saskatchewan. The Occupational Health and Safety Regulations, 1996 (2016) (PDF)
18. The Canadian Legal Information Institute (CanLII). Yukon’s Occupational Health Regulations, O.I.C. 1986/164 (2012) (PDF)
19. Ontario Ministry of the Environment and Climate Change. Ontario’s Ambient Air Quality Criteria (2016)
23. Health Canada. Cosmetic Ingredient Hotlist (2010)
26. Environment and Climate Change Canada. Toxic Substances List -CEPA Schedule 1 (2010)
28. Canadian Centre for Occupational Health and Safety (CCOHS). Headlines: Titanium Dioxide Classified as Possibly Carcinogenic to Humans (2006)
30. Madl AK, Pinkerton KE. “Health effects of inhaled and incidental nanoparticles.” Crit Rev Toxicol 2009;39(8):629-658.
31. Rio Tinto. QIT Fer et Titane (2005)
32. International Trade Centre. TradeMap (Free subscription required)
33. World Health Organization (WHO). Environmental Health Criteria 24 – Titanium (1982)
34. Environment and Climate Change Canada. National Pollutant Release Inventory (NPRI) Facility Search (Substance name: ‘Titanium dioxide’)
35. US Household Products Database (HPD). Household Products (Search term: ‘Titanium dioxide’)

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