Diacetyl exposures at four microwave popcorn plants

Area of Science:

• Occupational Health and Safety
• Industrial Hygiene
• Chemical Exposure Assessment

Background:

• Diacetyl is a butter-flavoring compound used in microwave popcorn manufacturing.
• Concerns exist regarding worker exposure to diacetyl and potential health risks.

Purpose of the Study:

• To assess diacetyl exposure levels in microwave popcorn manufacturing plants.
• To compare exposure levels between different job roles (Mixers vs. Non-mixers).
• To evaluate the impact of engineering controls on diacetyl exposure.

Main Methods:

• Personal, breathing zone air samples collected using NIOSH Method 2557.
• Samples analyzed from workers in four US microwave popcorn plants (2005-2007).
• Data analyzed by job duty, geometric mean, and arithmetic mean, considering humidity levels.

Main Results:

• Mixers showed higher diacetyl exposure (geometric means 0.029-0.231 ppm) compared to Non-mixers (0.001-0.018 ppm).
• Nearly 50% of all samples were below the limit of detection.
• Ventilation improvements at one plant reduced exposure from 0.614 ppm to 0.061 ppm.

Conclusions:

• Diacetyl exposure varies significantly by job role in microwave popcorn production.
• Engineering controls, such as improved ventilation, are effective in reducing diacetyl exposure.
• Further characterization of diacetyl exposure was limited by its subsequent removal from the product.