A paper published in Toxicology Reports suggests that roasting and grinding coffee could expose workers to levels of diacetyl – a compound associated with chronic lung disease – that exceed recommended short-term occupational exposure levels.
Diacetyl is found in flavouring added to products in the food industry but is also now known to formed naturally, during the roasting and grinding process. It has been linked to illness in workers at plants where microwave popcorn is produced, and more than 1,000 lawsuits have been filed with awards and settlements exceeding millions of dollars, causing the food industry to move away from the use of synthetic diacetyl.
In mid-2015, an investigation by reporters at the Milwaukee Journal Sentinel found that levels of naturally occurring diacetyl and 2, 3-pentanedione (known as diketones) to which workers at two Wisconsin coffee roasters were exposed exceeded safe levels recommended by the Centres for Disease Control and Prevention. In some cases, the levels were nearly four times the recommended limit.
Now, a study published in Toxicology Reports suggests that exposure to naturally produced diacetyl from coffee roasting really could be a potential health issue, and suggests that further research should be carried out to analyse naturally occurring diketone levels during coffee grinding and/or brewing in industrial processing, coffee shop, and even home settings.
It also recommends that thorough epidemiology studies of workers exposed to diacetyl and/or 2, 3-pentanedione alone be carried out to determine if either of the diketones is capable of causing obstructive lung disease in humans exposed to plausible concentrations.
“Until this relationship is known,” said the authors of the study, who work for Cardno ChemRisk, an internationally-recognised scientific consulting firm that focuses on understanding the hazards posed by chemicals in foods, “we recommend that alternative methods for setting diketone occupational exposure level (OELs) be applied to these compounds.”
