Roasting coffee beans naturally produces diacetyl and 2,3-pentanedione (Daglia
et al. 2007). Volatile organic compounds, including alpha-diketones (e.g,
diacetyl and 2,3-pentanedione), can be released during grinding of coffee
(Akiyama et al. 2003). National Institute for Occupational Safety and Health
(NIOSH) investigators have developed a coffee processing webpage with interim
recommendations.

In coffee processing facilities, air sampling for diacetyl and 2,3-pentanedione
can help determine if control measures are needed to reduce airborne
concentrations of alpha-diketones. Area and personal air sampling as well as
air sampling during specific tasks such as roasting, grinding, and pouring and
adding flavorings can help characterize exposures by area, job, and task. NIOSH
has published proposed recommended exposure limits (RELs) for diacetyl and
2,3-pentanedione in workplace air. The NIOSH proposed REL is 5 parts per
billion (ppb) for an 8-hour time-weighted average (TWA) for diacetyl and 9.3
ppb for an 8-hour TWA for 2,3-pentanedione. The NIOSH proposed 15-minute
short-term exposure limit (STEL) is 25 ppb for diacetyl and 31 ppb for
2,3-pentanedione (NIOSH 2011). The NIOSH proposed standards do not
differentiate between natural and synthetic chemical origin of diacetyl or
2,3-pentanedione.

More information

AplusA-online.de - Source: The National Institute for Occupational Safety and Health (NIOSH)