NIOSH Releases Two Guidelines for Titanium Dioxide
Current Intelligence Bulletin 63 is the first time the agency has issued separate guidelines for the same chemical based on particle size.
NIOSH for the first time has released two guidelines for the same chemical, titanium dioxide, based on particle size. The agency released its Current Intelligence Bulletin 63: Occupational Exposure to Titanium Dioxide on April 14.
Titanium dioxide is an insoluble white powder used in paints, cosmetics, plastics, paper, and food; the guidelines indicate ultrafine particles of TiO2 are more hazardous by inhalation to workers than fine particles of the chemical. The TiO2 CIB makes recommendations for occupational exposure limits and suggests techniques for monitoring and controlling exposures.
The bulletin:
- Reviews data relevant to assessing the carcinogenicity and other adverse health effects of TiO2.
- Provides quantitative risk assessments and recommended exposure limits for fine and ultrafine TiO2. NIOSH said laboratory data shows ultrafine particles "demonstrated greater potency in laboratory rats than fine particles did, when the dose was expressed by particle surface area. This greater potency was associated with the greater surface area of the ultrafine particles for a given mass."
- Describes exposure monitoring techniques, exposure control strategies, and future research needs.
"The guidance in this Current Intelligence Bulletin will protect workers also in reflecting our efforts to use our science to better understand and address particles on the nanoscale," said NIOSH Director Dr. John Howard. "As NIOSH continues to conduct research into the occupational health implications of nanotechnology, guidance of this nature will play an increasingly important role in fashioning protective occupational safety and health practices."