NORA Manufacturing Sector Strategic Goals
927ZCTU - Evaluation of Diacetyl Sampling MethodsStart Date: 1/1/2008
End Date: 9/30/2009
Principal Investigator (PI)Organization: NIOSH
Funded By: NIOSH
Primary Goal Addressed5.0
Secondary Goal Addressed8.0
Attributed to Manufacturing
This project is undertaken to study the effects of relative humidity on measured air concentrations of diacetyl using NIOSH Methods 2557 (diacetyl), 2558 (acetoin), and for comparison, a modified OSHA method (OSHA PV2118 using large silica gel tubes). Specifically, we want to determine: 1) Does the relative humidity level impact the quantification of diacetyl in air samples by causing reduced analyte recovery and 2) If relative humidity impacts diacetyl air sampling results, can an adjustment factor(s) be developed to allow correction of existing diacetyl sampling data. Additionally, this project will provide the opportunity to assess direct reading air sampling instruments for their accuracy and reproducibility in the measurement of diacetyl concentrations. These efforts will be completed using the sampling chambers at the OSHA Salt Lake City Lab and at the NIOSH / HELD Laboratories in Morgantown, WV.
Some of the questions to be addressed by this study include: What is the quantitative effect of humidity / relative humidity on NIOSH Methods 2557, 2558, and a modified OSHA PV2118 (using a large silica gel tube) over a range of temperatures, humidities, diacetyl concentrations, sampling flow rates, and sample storage times?; What are optimal flow rates / sampling volumes for these methods?; If relative humidity effects are observed, can a conversion factor(s) be developed to adjust past industrial hygiene sampling data using NIOSH methods 2557 and 2558 over a range of temperatures, relative humidity levels, sample flow rates, sample storage times, and diacetyl levels?; What is the performance of available direct-reading methods for real time assessment of diacetyl exposure (Fourier transformed infrared (FTIR) spectroscopy for diacetyl; photo-ionization meter for organic vapors; portable GC and GC-MS for diacetyl) relative to the previously-described methods?
Studies addressing these questions will, in large part, use well-characterized atmospheres generated in laboratory test chambers to characterize and compare current exposure assessment methods. Initial pilot testing will be conducted at the OSHA Salt Lake City Laboratory; At this lab, OSHA has a chamber already up and running that could be used to generate known concentrations of diacetyl and relative humidity. Jerry Schultz and Mary Eide from this laboratory have actively collaborated with NIOSH on this issue. This work will begin in January of 2008 with a one week trip to the OSHA Laboratory for pilot sampling. Subsequent chamber studies would be performed in collaboration with OSHA and with NIOSH / HELD during 2008. Researchers at NIOSH / HELD have past experience in doing this type of chamber work for animal exposures and will develop suitable testing chambers at the NIOSH / Morgantown Laboratories to support the current work. Also, as opportunities become available through the NIOSH HHE Program, various methods will be compared in the field at work places that use flavorings containing diacetyl. This will also provide an opportunity to assess exposures to dry powders containing diacetyl. (Dry, encapsulated powders containing diacetyl can potentially dissolve and release the diacetyl after contact with a wet surface, such as the respiratory tract. This could pose exposure hazards comparable to diacetyl vapor exposure. Exposure assessment methods need to be developed to allow the quantification of diacetyl in airborne particulate samples).
This project evaluation will be rated as successful based on the following outputs: Report summarizing quantitative effect of humidity / relative humidity on NIOSH Methods 2557, 2558, and a modified OSHA PV2118 (using a large silica gel tube) over a range of temperatures, humidities, diacetyl concentrations, sampling flow rates, and sample storage times; Report summarizing optimal flow rates / sampling volumes for these methods; Determination of a conversion factor(s) to adjust past industrial hygiene sampling data using NIOSH methods 2557 and 2558 over a range of temperatures, relative humidity levels, sample flow rates, sample storage times, and diacetyl levels; Report dealing the performance of available direct-reading methods for real time assessment of diacetyl exposure (Fourier transformed infrared (FTIR) spectroscopy for diacetyl; photo-ionization meter for organic vapors; portable GC and GC-MS for diacetyl) relative to the previously-described methods.
If conversion factor(s) is determined, this project impact will be evaluated by its use in quantitative risk assessment using historically collected data by EID over the next 3-5 years.
Flavorings-induced lung disease is an important and high profile issue for NIOSH. The passage on September 26, 2007, by the House of Representatives of H.R. 2693, the "Popcorn Workers Lung Disease Prevention Act," creates additional urgency for NIOSH work in this area. The act specifies that, "not later than 90 days after the date of enactment of this Act, the Secretary of Labor shall promulgate an interim final standard regulating worker exposure to diacetyl." The interim final standard will apply to the flavoring manufacturing industry and to microwave popcorn production and packaging establishments. The act specifies that the standard should address engineering and work practice controls, personal (including respiratory) protective equipment, airborne exposure assessment, hazard communication information, labeling, and training. In addition, the act requires promulgation a final standard not later than 2 years after enactment. "The final standard shall contain, at a minimum, the worker protection provisions in the interim final standard, a short term exposure limit, and a permissible exposure limit that does not exceed the lowest feasible level, and shall apply at a minimum to all facilities where diacetyl is processed or used."
There is urgency for NIOSH to address lingering scientific issues relevant to prevention of flavoring-induced lung disease. One major obstacle to addressing requirements under the act (including the development of exposure limits) is the lack of a validated exposure assessment method for diacetyl. There is preliminary data to suggest that the current NIOSH and OSHA methods for exposure assessment (NIOSH method #2557, http://www.cdc.gov/niosh/nmam/pdfs/2557.pdf; and OSHA method # PV2118, http://www.osha.gov/dts/sltc/methods/partial/t-pv2118/t-pv2118.html) might underestimate exposure in the presence of high relative humidity. This has been a source of great stakeholder concern, as documented by stakeholder comments at a recent public meeting held by OSHA on October 17, 2007.
There is a need to "fast-track" research addressing diacetyl exposure assessment methods for the food and flavorings industry. This proposal, therefore, is undertaken to address the sampling and analytical methods issues including the effects of relative humidity on NIOSH Method 2557 and 2558, development of correction factors for past diacetyl and acetoin exposure assessment using these methods. This project will also address the accuracy and reproducibility of diacetyl measurements made using direct reading instruments for exposure assessment.
The need for this project is based on surveillance data generated through Health Hazard Evaluation Program.
Strategic Goal 5: Reduce the number of respiratory conditions and diseases due to exposures in the manufacturing sector.
Cross Sector: Respiratory Diseases
RDR - SG1:IG1.2 Prevent and reduce work-related COPD.
Exposure Assessment -
EXA - SG1 Develop or improve exposure assessment strategies to understand and prevent work-related illnesses and injuries. SG2 Develop or improve specific methods and tools to assess worker exposures to critical occupational agents and stressors.
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