Titanium Dioxide (TiO2)
Air Sampling for this Potential Occupational Carcinogen
Clearwater, Florida - April, 2011 -- The National Institute for Occupational Safety and Health (NIOSH) recently released an intelligence bulletin (CIB 63) titled Occupational Exposure to Titanium Dioxide where the quantitative risk of Titanium Dioxide exposure is addressed.
Titanium dioxide (TiO2) (Chemical Abstract Service [CAS] Number 13463–67–7) is a noncombustible, insoluble, white, crystalline, solid, odorless powder. TiO2 is used extensively in many commercial products, including paints and varnishes, cosmetics, plastics, paper, and food as an anticaking or whitening agent. Production in the United States was an estimated 1.45 million metric tons per year in 2007 [DOI 2008].
TiO2 is produced and used in the workplace in varying particle size fractions including fine (defined as all particle sizes collected by respirable particle sampling) and ultrafine (defined as the fraction of respirable particles with a primary particle diameter of <0.1 μm [<100 nm]). Particles <100 nm are also defined as nanoparticles.
NIOSH recommends exposure limits of 2.4 mg/m3 for TiO2 and 0.3 mg/m3 for ultrafine (including engineered nanoscale) TiO2, as time weighted averge (TWA) concentrations for up to 10 hours per day during a 40-hour work week. NIOSH determined that ultrafine TiO2 is a potential occupational carcinogen. NIOSH will continue research to determine if fine TiO2 should also be classified as a potential occupational carcinogen.