NORA Manufacturing Sector Strategic Goals
927ZJLRa - Engineering Controls for Nanomaterial Handling (NTRC)Start Date: 10/1/2009
End Date: 9/30/2012
Principal Investigator (PI)Name: Li Ming Lo
Funded By: NIOSH
Primary Goals Addressed5.09.0
Secondary Goal Addressed
Attributed to Manufacturing
This project intends to evaluate the performance of real-world engineering controls for CNTs or other nanomaterials in the aerosol phase to lower the potential risks to workers. We will focus on the exposure assessment of both SWCNTs and MWCNTs in either unpurified or purified forms during manufacturing and handling processes. We first need to identify the specific tasks and processes that likely produce the highest exposures during CNT handling. The effectiveness of practical engineering controls will be evaluated in both the laboratory and the field. Other measurement metrics including particle number and surface area concentration will also be collected to evaluate control effectiveness. Ultimately, the guidance developed from this project should provide recommendations for selecting optimum controls for specific nanomaterial handling processes.
The project design is based on a one-year field study of extensive data collection for exposure to CNT manufacturing and handling, and a two-year laboratory study to develop guidance for safely handling nanomaterials and optimum use of engineering controls to lower nanoparticle exposure in the workplace. The field investigation will be performed in appropriate sites based on the criteria such as production scale, specific tasks, and engineering controls used in facilities to reduce CNT emission. To evaluate exposure risk, exposure assessment is expected to determine biologically relevant exposure for individual workers. Since current toxicological research has not reached agreement on the most relevant dose-metric for exposure to nanoparticles, we will collect different metrics including number, surface area, and mass concentrations, and particle morphology. This extensive investigation will allow us to understand workplace processes and factors that determine and influence exposure to nanomaterials. In this study, we will also focus on the controls and their effectiveness.
A test chamber for the experimental study will be constructed in the Ventilation Lab, NIOSH Hamilton Laboratory. Based on the data collected from the field study, the test chamber will be designed to have a controllable flow pattern to test different activities in the nanotechnology workplace. In this single-source exposure scenario, the temporal and spatial variations of nanoparticle concentrations caused by specific actions can be characterized accurately to assess instantaneous and average exposures. Using statistical experimental design, we plan to test any practical control for a specific task to provide guidelines for appropriate use of engineering controls for nanomaterial manufacturing and handling. The experimental results will help identify the critical tasks and processes that likely produce the highest CNT exposures, to demonstrate the optimum controls for CNT handling.
Our ultimate objective is to use the data from the initial field research for the subsequent experimental study. In this way, we will be able to evaluate the performance of available engineering controls and promote their use for nanomaterial manufacturing and handling. This study will allow us to develop guidance for safely handling nanomaterials.
The overall objective of this project is to develop guidance for engineering controls for CNTs during manufacturing and handling in the workplace. The comprehensive guidance is also expected to be applicable to other nanomaterials being handled in the aerosol phase. The proposed research consists of a field evaluation and a laboratory study. The field evaluation helps us collect comprehensive data for developing initial guidance and estimating existing exposure levels. The laboratory study can systematically evaluate the effect of different controls on specific tasks to provide complete guidance for optimizing the control of nanomaterials in the workplace.
Specific aims of the field evaluation are to
(1) catalog existing engineering control devices used in CNT handling processes;
(2) measure the exposure levels associated with tasks or processes;
(3) evaluate the range and effectiveness of controls; and
(4) improve the control efficiency by adopting new controls or changing operational practices.
Specific aims of the laboratory study are to
(1) identify the tasks or processes likely producing the highest exposures; and
(2) promote control efficiency through statistical experimental design to clarify effects of possible control device on different handling process.
The evaluation of the effectiveness of controls and development of guidance for controlling hazards associated with CNTs and other nanomaterials is one of three priorities for NIOSH NTRC research efforts. However, to date there are no regulations that respond to an increased awareness of the potential health risks caused by nanomaterials. There are only general guidelines for reducing exposures while handling nanomaterials available, but they are mainly based on conventional safe practices for handling chemicals.
No surveillance information has been used in this project.
This study supports the research priorities of NIOSH NTRC: engineering control evaluation and guidance development. The results from our laboratory experiments and field surveys specifically address strategic National Occupational Research Agenda (NORA) goals related to exposure reduction and knowledge enhancement under the Manufacturing Sector, and advancement of control technology under the Engineering Controls Cross-Sector.
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