Diacetyl Exposures in Coffee Roasting & Grinding Facilities and Nonproduction Areas
Abstract No:
1291
Abstract Type:
Professional Poster
Authors:
H Drzymala1
Institutions:
1Liberty Mutual Insurance, Minnetonka, MN
Presenter:
Heather Drzymala, CSP, CIH
Liberty Mutual Insurance
Liberty Mutual Insurance
Description:
Diacetyl exposures can vary greatly and can often exceed the occupation exposure limits for employees roasting and grinding coffee. Elevated levels can also permeate to other areas of the facility including warehouse and office areas. This poster session will examine the exposures of employees conducting roasting, grinding and packaging as well as potential exposures in nonproduction areas such as offices and warehouse areas.
Situation / Problem:
Sampling for diacetyl exposure was performed to determine the extent of migration of fugitive vapors in two facilities performing coffee roasting, grinding and packaging. Air sampling was also performed on the rooftop to determine if fugitive vapors from roof exhaust was being re-entrained back through fresh air intakes of nearby HVAC air handling units.
Methods:
Diacetyl samples were collected at two different coffee facilities conducting roasting, grinding and packaging. Samples were collected through two 600 mg tubes in series that contain specially cleaned and dried silica gel at 0.07 L/min for approximately 90-120 minutes for a time-weighted average (TWA) concentration using MSA Escort ELF sampling pumps with low-flow adapters. The tubes were also wrapped in aluminum foil during and after sampling to protect the samples from light exposure. The tubes were positioned in the worker's breathing zone. The sampling train flow rates were pre and post calibration verified using a Bios DryCal primary calibrator. All post sampling flow rates were within 5% of presampling values. The samples were analyzed using OSHA ID-1016 and OSHA 1013 methods at the Liberty Mutual Industrial Hygiene Analytical Laboratory in Hopkinton, Massachusetts, an AIHA Accredited Laboratory.
Results / Conclusions:
Diacetyl results for grinders and roasters ranged from 0.037 ppm to 0.089 ppm. Samples in nonproduction areas ranged from 0.013 ppm to 0.059 ppm, most likely due to pressure differences and entranceways near production areas. Diacetyl vapors were detected at the exhaust discharge stacks on the roof at concentrations ranging from 0.055 ppm to 0.075 ppm. Airborne concentrations were below LOQ at the fresh air intakes of the nearby air handling units, based on the wind conditions at the time. Sampling shows that although building ventilation is removing some diacetyl vapors from the facilities, diacetyl concentrations remain elevated in both production and nonproduction areas. The elevated results in nonproduction areas shows employees not previously thought to have diacetyl exposures can be overlooked when assessing exposures and control plan options. There is the potential to reduce the diacetyl exposure for nonproduction employees by increasing awareness of this hazard and improved controls for diacetyl vapors in all areas of the coffee roasting and grinding facility.
Primary Topic:
IH Profession
Secondary Topics:
Exposure Assessment Strategies
Co-Authors
Please add your co-authors below. Co-authors are listed for professional courtesy and will not be communicated with regarding the decision notification or any on-site logistics, if accepted. Only the primary presenter listed is expected to attend and present the content on-site.
Acknowledgements and References
List any additional people who worked on the project or provided guidance and support along with details on the role they played in the research. (Please include first name, last name, organization, city, state and country).
Richard Newton, Liberty Mutual Insurance, Atlanta, GA, United States - consulted on sampling methods and poster session
Tyler Erickson, Liberty Mutual Insurance, Minneapolis, MN, United States - sampling assistance on location