July 14, 2022

New Skin Notation Profile Focuses on Flavoring Compounds

A new skin notation profile for the flavoring compound diacetyl and its substitute, 2,3-pentanedione, was published last week by NIOSH. The substances carry the SEN and DIR (IRR) designations, which indicate that they may cause immune-mediated reactions and irritation following dermal exposure.

Occupational exposures to both chemicals have been linked to decreased lung function and to the severe, irreversible lung disease obliterative bronchiolitis. Other health effects of occupational exposure to diacetyl and 2,3-pentanedione include irritation of the skin, eyes, and respiratory tract. A NIOSH topic page on flavorings-related lung disease provides information about previous agency research and investigations focused on the microwave popcorn and flavorings manufacturing industries.

New skin notation profiles for chlorodiphenyl (54% chlorine); dioxane; beta-chloroprene; and 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and the mixture of 2,4- and 2,6-toluene diisocyanate are also available. According to NIOSH, chlorodiphenyl (54% chlorine) was previously used as a dielectric fluid, hydraulic fluid, and rubber plasticizer, and may be present in transformers and capacitors that are still in use today. Dioxane is primarily used as an organic solvent, while beta-chloroprene is used as an intermediate in the production of artificial rubber and neoprene, the agency says. And 2,4-toluene diisocyanate is used as a chemical intermediate in the production of polyurethane products like foams, coatings, elastomers, adhesives, and sealants.

NIOSH skin notations offer warnings about the direct, systemic, and sensitizing effects of chemical exposures to the skin. Each skin notation profile includes a brief summary of epidemiological and toxicological data associated with skin contact with a chemical and the rationale behind the chemical’s hazard-specific skin notation assignment.

All final skin notation profiles are available via the NIOSH website. To learn more about the NIOSH strategy for assigning skin notations, see NIOSH Current Intelligence Bulletin 61.

Related: In 2016, NIOSH researchers raised concerns that workers at coffee processing facilities are also at risk for lung disease caused by occupational exposure to diacetyl and 2,3-pentanedione, which are naturally produced and released when coffee beans are roasted and when coffee is ground.