Safety Alert Issued Regarding Diacetyl in Coffee and Food Flavour Manufacture

The HSE recently issued a safety alert regarding the dangers of exposure to diacetyl vapour in food and drink manufacture.

Diacetyl is an organic chemical occurring naturally in alcoholic beverages which has a buttery flavour making it a popular choice of food flavouring. It is particularly prevalent in artificial butters and margarines as it is the diacetyl that gives these substitutes their butter-based flavour as well as in popcorn, crackers, and crisps. It can also be produced synthetically with synthetic diacetyl being classified as a hazardous substance due to it causing skin irritation, damage to the eyes upon contact and danger when ingested.

Diacetyl is also produced as a by product of coffee roasting.

Recent research for the HSE found that when heating diacetyl above certain temperatures there is a significant increase in airborne concentrations of diacetyl, potentially exceeding safe workplace limits. In coffee manufacture significantly higher concentrations were found if roasted beans were ground while still warm (around 40°C).

Risks must be assessed in workplaces where diacetyl or food flavouring that contain diacetyl are used or where diacetyl is likely to be produced must carry out a risk assessment. If the risk assessment finds that the level of diacetyl exposure is above the workplace exposure limit and the business is unable to substitute for a safer alternative or control the risk of exposure to a level in which employees are unlikely to be harmed, then a health surveillance programme must be established.

The HSE has specified that there are two primary areas of risk regarding diacetyl. The first of these is a risk in coffee manufacture as a result of bean roasting and the other being a risk in flavour manufacturing. Within flavour manufacture the HSE has highlighted that a risk of exposure can occur at numerous points:

• When opening diacetyl or flavouring containers
• When decanting and weighing
• When mixing
• When spray drying to produce powdered mixtures
• When packaging
• When cleaning vessels or spillages

The risk can occur even if concentrations as low as 5% are heated, added to hot processes or are spray dried.

If you have any questions or would like support with managing issues at your workplace, please speak to your usual contact or get in touch using the form below.