Is Popcorn dangerous?

No this is not a trick question. “Popcorn Lung” more correctly known as “bronchiolitis obliterans”, is a rare and irreversible illness that can affect people who inhale large amounts of the chemical Diacetyl, which is a volatile, colourless liquid with an intensely buttery flavour. Diacetyl occurs naturally in alcoholic beverages and has been added to some foods to impart its buttery flavour.

The United States National Institute for Occupational Safety and Health has suggested diacetyl, when used in artificial butter flavoring, may be hazardous when heated and inhaled over a long period. Workers in several factories that manufacture artificial butter flavoring have been diagnosed with this condition, but these cases have been mainly in young, healthy, non-smoking males.

In 2006, a petition was launched in the U.S to promulgate an emergency temporary standard to protect workers from the deleterious health effects of inhaling diacetyl vapours. This petition gained the support of more than 30 prominent scientists.

A 2010 OSHA Safety and Health Information Bulletin and companion Worker Alert recommended that employers use safety measures to avoid exposing employees to the potentially deadly effects of butter flavourings and other flavouring substances containing diacetyl or its substitutes.

However, as early as 2004 a Missouri couple were awarded $20 million for “popcorn lung”. This case would be the first of a series of lawsuits brought by workers against the makers of butter flavourings.

In 2012, Wayne Watson, a regular microwavable popcorn consumer for years, was awarded $7.27 million in damages from a federal jury in Denver, which decided that his lung disease was caused by the chemicals in microwave popcorn. Mr Watson’s case was helped by the testimony of Dr Cecile Rose, the doctor who diagnosed him with the condition. She had been a consultant to the flavourings industry and had seen the same disease Mr Watson had developed among workers exposed to the chemical. Watson was the first, and possibly only, popcorn eater to come down with popcorn lung.

However, the European Commission has declared diacetyl is legal for use as a flavouring substance in all EU states, finding that there were no safety concerns for diacetyl’s use as a flavouring.

So should you try to avoid microwave popcorn?

While most microwave popcorn manufacturers have removed diacetyl from their products a worrying new cause of “bronchiolitis obliterans” has been suggested from E-cigarettes. Or, more accurately, the vapours they give off. Diacetyl is a chemical used in several popular flavours, like vanilla, and may not be something that you want to inhale on a regular basis.

That said is diacetyl only likely harmful if – for example – it’s inhaled in quantities / concentrations akin to those found in an industrial setting?

Perhaps a sensible approach would be to take things in moderation. Fortunately, such awards will not be found here in the UK.