NORA Manufacturing Sector Strategic Goals
927008C - Titanium Dioxide Exposure Assessment
Principal Investigator (PI)
Primary Goal Addressed
Secondary Goal Addressed
Attributed to Manufacturing
In response to requests from industry groups, NIOSH is reevaluating whether exposure to titanium dioxide (TiO2) has the potential to cause lung cancer and other respiratory diseases in occupational settings. NIOSH is developing a Current Intelligence Bulletin (CIB) that describes the extent and characteristics of workplace exposures and provides recommendations for preventing adverse health effects.
Evidence from a number of animal studies suggest that the toxicity and carcinogenicity of poorly soluble, low toxicity (PSLT) particles, including TiO2, are not substance-specific effects, but are related to the particle surface area dose. In rats chronically exposed to pigment-grade (fine) TiO2, increased lung tumors were observed only at a dose much higher than current occupational exposure limits for TiO2 and other PSLT particles; however, in rats exposed to ultra-fine (nano-sized) TiO2, lung cancer was elevated at occupationally relevant doses. Epidemiological studies of workers exposed to fine titanium dioxide have not shown an elevation in lung cancer. An estimated 2.75 million U.S. workers have been documented from the NIOSH National Occupational Exposure Survey (1981-1982) as potentially exposed to TiO2.
A Current Intelligence Bulletin (CIB) will be drafted in FY07 pending completion of field studies conducted by DSHEFS. This document will supplement the CIB entitled "Evaluation of Health Hazard and Recommendations on Occupational Exposure to Titanium Dioxide" by describing the characteristics of exposure in various workplaces, recommending methods for monitoring exposures, and providing guidance on the control of exposures. The document will be developed in collaboration with the NIOSH NTRC to ensure that recommendations are consistent with those being recommended by NIOSH for other nanomaterials. Collaborative efforts have been initiated with representatives of the Titanium Dioxide Panel, American Chemistry Council on collecting exposure data and information on exposure controls methods. In collaboration with NIOSH NTRC and DSHEFS staff, information on exposure characteristics, sampling methodologies, and exposure control strategies will be gathered from small nanotechnology companies that produce ultrafine (nano-size) TiO2 and from the use of ultrafine TiO2 in the cosmetic industry. The time frame for completing the CIB is contingent upon gathering relevant exposure data, an assessment of the feasibility to control exposures at the NIOSH REL, and development of appropriate sampling and analytical methods.
The objective of this project is the development a NIOSH Current Intelligence Bulletin (CIB) that will describe the extent and characteristics of TiO2 exposure in the workplace, provide strategies for preventing exposures (e.g., engineering controls) as well as recommendations for personal protective equipment (e.g., respirators). The information contained in this document will complement the NIOSH CIB "Evaluation of Health Hazard and Recommendations for Occupational Exposure to Titanium Dioxide" that describes the specific health effects associated with TiO2 exposure along with recommended exposure limits.
In 1988, NIOSH recommended to OSHA that pigment-grade (fine) titanium dioxide (TiO2) be classified as a potential occupational carcinogen based on evidence of an increase in lung tumors observed in an experimental chronic inhalation study with rats. The production of TiO2 in the United States is estimated at 1.43 million metric tons with approximately 2 to 3 million workers potentially exposed. Based on a recent review of the literature NIOSH has determined that its policy on TiO2 may not adequately reflect the current scientific knowledge about the potential biological activity of TiO2 and other similar substances that have poor solubility. A Current Intelligence Bulletin (CIB) entitled "Evaluation of Health Hazard and Recommendations on Occupational Exposure to Titanium Dioxide" was initiated in FY05 to evaluate the health data and develop a recommended exposure limit (REL) for TiO2. To complement the development of this CIB, another CIB entitled "Titanium Dioxide Exposure Assessment" was initiated in FY07 that characterizes occupational exposure to TiO2, assesses the feasibility of controlling exposure, and makes recommendations for measuring and controlling exposures. The CIB will provide manufacturers and users of TiO2 with guidance on the safe handling of TiO2 and practical methods for characterizing and measuring airborne exposures. The development of the CIB fulfills one of NIOSH's primary missions to develop recommendations for the prevention of occupational injuries and illnesses.
This research to practice project will produce communication products supporting the NIOSH mission to assure a safe and healthful workplace.
This project support the following goals:
Strategic Goal 9 (09PPMNFSG9): Enhance the state of knowledge related to emerging risks to occupational safety and health in manufacturing.
Strategic Goal 5 (09PPRDRSG5):
Prevent respiratory and other diseases potentially resulting from occupational exposures to nanomaterials.
Intermediate Goal (09PPRDRIG5.2): characterize respiratory exposures and measures used to reduce exposures, including engineering controls and respiratory protection, in work settings where engineered nanomaterials are produced or used.
Activity/Output Goal (09PPRDRAOG5.2.1): develop partnerships and conduct field evaluations of facilities where nanomaterials are produced or used.
Intermediate Goal (09PPRDRIG5.3): develop guidance for facilities that produce or use nanomaterials.
Activity/Output Goal (09PPRDRAOG5.3.1): complete guidance documents on medical surveillance and use of control banding in facilities where nanomaterials are produced or used.
Authoritative Recommendation Development
Strategic Goal 1 (09PPAURSG1): Reduce and prevent occupational injuries, illnesses, and fatalities by supporting NORA sector and cross-sector programs in the development of authoritative recommendations.
Strategic Goal 2 (09PPEXASG2): Develop or improve specific methods and tools to assess worker exposures to critical occupational agents and stressors.
Intermediate Goal 2.11 (09PPEXAIG2.11): Address critical exposure assessment needs in emerging areas such as nanotechnology for application of new approaches to both new and traditional industrial processes, and for emerging initiatives to substitute alternative (e.g., ostensibly more safe) chemical processes in areas where hazards have been identified.
Activity/Output 2.11.1 (09PPEXAAOG2.11.1): Development of exposure assessment tools to characterize and evaluate the exposure to these emerging areas.
Strategic Goal 1 (09PPNANSG1). Determine if nanoparticles and nanomaterials pose risks for work-related injuries and illnesses.
d. Conduct research on measuring nanomaterials in the workplace, including developing new measurement methods and validating measurement methods.
Intermediate Goal 1.1 (09PPNAN1G1.1) Fate of nanomaterials in the work environment. Determine the key factors influencing the generation, dispersion, deposition, and re-entrainment of nanomaterials in the workplace, including the role of mixed exposures. Performance Measure 1.1 Support at least 12 research projects (field trips) over the next three years to assess the fate of nanomaterials in the work environment.
Intermediate Goal 1.2 (09PPNANIG1.2) Worker exposures. Quantitatively assess exposures to nanomaterials in the workplace including inhalation and dermal exposure. Determine how exposures differ by work task or process.