Correcting diacetyl concentrations from air samples collected with NIOSH method 2557

Area of Science:

• Occupational Health and Safety
• Industrial Hygiene
• Analytical Chemistry

Background:

• Diacetyl (2,3-butanedione) is used as a flavoring agent and linked to bronchiolitis obliterans.
• NIOSH Method 2557 was used for workplace diacetyl monitoring but may underestimate concentrations.
• Accurate exposure assessment is crucial for evaluating respiratory health risks.

Purpose of the Study:

• To investigate the impact of humidity and storage duration on diacetyl recovery using NIOSH Method 2557.
• To develop a mathematical correction procedure for historical diacetyl exposure data.
• To enable more accurate quantitative risk assessment for diacetyl exposure.

Main Methods:

• Experimental air samples were collected in a controlled test atmosphere with variable humidity and temperature.
• Samples were analyzed using NIOSH Method 2557, and results compared to theoretical concentrations.
• Nonlinear models were fitted to experimental data to identify factors affecting diacetyl recovery.

Main Results:

• Absolute humidity, diacetyl concentration, and sample storage duration significantly affected diacetyl recovery.
• Sampling flow rate had a smaller impact on diacetyl recovery.
• A mathematical correction procedure was derived based on these factors.

Conclusions:

• A correction procedure can improve the accuracy of historical diacetyl exposure data obtained with NIOSH Method 2557.
• This correction allows for more reliable quantitative risk assessments of diacetyl-related health effects.
• Accurate exposure data is essential for protecting worker health in industries using diacetyl.