NIOSH Seeks Comment on Diacetyl Document

The National Institute for Occupational Safety and Health (NIOSH) seeks public comment on a draft document concerning occupational exposure limits and control recommendations for the food flavorings diacetyl and 2,3-pentanedione.

Occupational exposure to diacetyl, which is used to add flavor and aroma to food such as microwave popcorn, has been linked with debilitating lung disease. While some manufacturers began using 2,3-pentanedione in place of diacetyl, health concerns are associated with this substitute, as well.

NIOSH’s draft document, “Criteria for a Recommended Standard: Occupational Exposure to Diacetyl and 2,3-pentanedione,” recommends the following exposure limits for diacetyl and 2,3-pentanedione:

Diacetyl – a recommended exposure limit (REL) of 5 parts per billion (ppb) as an 8-hour, time-weighted average during a 40-hour workweek. NIOSH also recommends a short-term exposure limit (STEL) for diacetyl of 25 ppb for a 15-minute time period.

2,3-pentanedione – an REL of 9.3 ppb as an 8-hour, time-weighted average during a 40-hour workweek. This REL is based on the lowest level at which the substance reliably can be detected using the existing analytical method, and should not be misconstrued to imply that 2,3-pentanedione is of lower toxicity than diacetyl. On the same basis of analytic method limitation, NIOSH also recommends an STEL of 31 ppb to limit peak exposures for 2,3-pentanedione.

"In addition to the recommended exposure limits, this draft document provides for public comment a comprehensive review of scientific literature, a quantitative risk assessment and valuable guidance to reduce occupational exposures to diacetyl and 2,3-pentanedione,” said NIOSH Director John Howard, M.D.

NIOSH will accept public comments on this draft document until Oct. 14 and will take them into consideration while developing final recommendations. The agency also will hold a public meeting in Washington, D.C., regarding comments on Aug. 26.

To read the draft document and to learn how to comment, visit
. For more information on the occupational health and safety implications of diacetyl, visit

TAGS: Archive Health
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