Microwaving Popcorn at home - potentially harmful if not fatal

David Michaels writes - "Popcorn Lung Coming to Your Kitchen? The FDA Doesn’t Want to Know". Bronchiolitis obliterans AKA "popcorn lung" is a fatal, irreversible lung problem caused by exposure to a ketone , diacetyl, a food flavouring chemical used in making pop corn which provides a "buttery" flavour to the finished product. ( 2,3-butanedione or by its Chemical Abstracts Service (CAS) number, 431-03-08.)

In July, Dr. Cecile Rose a senior occupational and environmental clinician at the National Jewish Medical and Research Center, the most prestigious lung disease hospital in the country - she has been a consultant to the Flavor and Extract Manufacturers Association (FEMA) – the association of companies that make food flavorings – for more than a decade and helped develop the industry’s Respiratory Safety Program.

According to CDC - "the flavorings industry has estimated that over a thousand flavoring ingredients have the potential to be respiratory hazards due to possible volatility and irritant properties (alpha, beta-unsaturated aldehydes and ketones, aliphatic aldehydes, aliphatic carboxylic acids, aliphatic amines, and aliphatic aromatic thiols and sulfides)."

She wrote to the FDA, CDC, EPA and OSHA, to explain that she had identified a patient ..

“with significant lung disease whose clinical findings are similar to those described in affected workers, but whose only inhalational exposure is as a heavy, daily consumer of butter flavored microwave popcorn.”

Food flavour chemicals may not be just killing workers but directly affecting people exposed to food flavor chemicals in their kitchens. See here for more information about ConAgra, manufacturers of the Redenbacher Brand know about the problems. Conagra sells 3 billion bags of microwave popcorn worldwide annually. Americans wolf down 39 million pounds, or about 156 million bags every year, according to the Snack Manufacturers Association.

The agencies response is detailed by David Michaels and he suggests is so lamentable that their failure to respond adequately is a sign that our public health protection system is in dire need of repair.

Here’s a brief review of what each agency is doing (or not doing) about food flavor chemicals, and, according to Dr. Rose, how they responded (or didn’t respond) to the letter.

1. The Food and Drug Administration (FDA)
The FDA has been asked several times to examine whether breathing diacetyl poses a risk to consumers. Each time, the agency has refused.

2. The Environmental Protection Agency (EPA)
The EPA announced that a study on the chemicals released in the popping and opening of packages of microwave popcorn was underway and was expected to be completed by the end of that year (2003). The results of that study still have not been published (promised this year), although the results have been shared with popcorn manufacturers.


As a direct result at least one manufacturer the Pop Weaver Company have announced they will soon be marketing a butter flavored microwave popcorn that doesn’t use diacetyl in the butter flavor. The Indiana based manufacturer sells “Trail’s End” popcorn for the Boy Scouts of America. Five million boxes were sold last year.

The Seattle Post- Intelligencer reported ..

"In part, it was the EPA’s study that led Pop Weaver to reformulate its flavoring without diacetyl, said Mike Weaver, chief executive officer of the 80-yearold family-owned company."

3. The Centers for Disease Control and Prevention (CDC)
The CDC is not a regulatory agency. It does play a central role in investigating the causes of illnesses and in alerting the public and medical communities about ways to prevent diseases from occurring.

The National Institute for Occupational Safety and Health (NIOSH), a branch of the CDC, has done terrific work investigating the causes of lung disease among flavor workers.

As of last week, CDC had not responded to the letter.

4. The Occupational Safety and Health Administration (OSHA)
OSHA is charged with protecting the health of workers, so the information in this letter wasn’t particularly relevant to their work. They responded promptly, thanking Dr. Rose for her letter.

David Michaels is Professor and Associate Chairman in the Department of Environmental and Occupational Health, the George Washington University School of Public Health and Health Services and heads the Project on Scientific Knowledge and public policy (SKAPP).

He concludes ;

At one time, the US regulatory agencies were the envy of the world.

The anti-regulation policies coming from the White House and the political hacks running the agencies have taken their toll. The agencies have fewer staff and fewer resources. Morale is at its lowest. Many of the best scientists have left and are not being replaced.

If you microwave popcorn at home - go and read the full article.

Better still - make it yourself - recipe and instructions here. Kids love making it....er...and eating it and you'll save money.

This is a site funded by Popcorn manufacturers which tells you what wonderful stuff they sell.

Microwave packaging may also present a health hazard...

At the FDA 2006 Science Forum TH Begley and others from the FDA drew attention to the use of Perfluorochemicals used in the manufacturing of food contact substances (FCS) which represent potential sources of oral exposure to these chemicals in a presentation "Characterizing perfluorochemical migration from food contact paper. "

Recent epidemiology studies have demonstrated the presence of two particular perfluorochemicals, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in human serum at very low part per billion (ppb) levels. These perfluorochemicals are biopersistent and are the subject of numerous studies investigating the many possible sources of human exposure. Because of this potential for biopersistence, FDA decided to evaluate the migration characteristics of perfluorochemicals from food contact paper.

Results from migration tests show that fluorotelomers from the paper additives/coatings do transfer to food. Some of the papers used for packaging food are treated with grease-repelling fluorotelomer coatings. Microwave popcorn bags have the most of any food wrappers—about 4000 milligrams per kilogram (mg/kg) in the coating or 25 mg per square decimeter of paper, the authors note.

Many of these coatings contain mixtures of long-chain chemicals that can be metabolized to PFOA, Begley and colleagues write in their Food Additives & Contaminants article.

The scientists found that a significant percentage of the fluorotelomers migrated from the bags to the popcorn oil, resulting in levels of 3–4 mg/kg.

Toxicologists commonly convert such an exposure into a human dose by dividing by the average adult body weight, 65 kg. This means that the average dose of fluorotelomers from each bag of popcorn is 1.7 micrograms per kilogram. Children who ate a whole bag would get a higher dose.

Begley notes. These high levels of migration are caused by high coating levels of fluorotelomers and alsobecause popcorn bags get very hot— in ecess of 200 °C in just a minute or two. These temperatures significantly increase the potential for migration of the packaging components to foods, he says. For more information go here

Ohio Citizen Action have taken this up (with little success) with ConAgra.

This is from their press release

See aso Papers: DuPont Hid Chemical Risk Studies ....

By JOHN HEILPRIN Associated Press November 17, 2005
WASHINGTON (AP) - DuPont Co. (DD) hid studies showing the risks of a Teflon-related chemical used to line candy wrappers, pizza boxes, microwave popcorn bags and hundreds of other food containers, according to internal company documents and a former employee.... Glenn Evers, told reporters at a news conference at Environmental Working Group, a research and advocacy organization, that the company long suppressed its studies on the chemical.

UPDATE re Diacetyl as aproduct of fermentation to enahnce b uttery flavour eg : some beers and Chardonnay wines.

The EU has not been idle in the matter
COMMISSION DECISIONof 18 May 2005
amending Decision 1999/217/EC as regards the register of flavouring substances used in or on
foodstuffs (notified under document number C(2005) 1437)
(Text with EEA relevance)
(2005/389/EC) " ....The Authority concluded in its opinion of 7 December 2004 on aliphatic dialcohols, diketones and hydroxyketones, that pentane-2,4-dione (FL 07.191) is genotoxic in vitro and in vivo. Accordingly, its use as a flavouring substance is not acceptable, because it does not comply with the general criteria for the use of flavouring substances set out in the Annex to Regulation"

(EC) No 2232/96. As a consequence, pentane-2,4-dione should be deleted from the register."

As the limiting concentration for flavour detection is 0.2mg / litre and is at most 1-2 mg per litre ingestion is low - lord knows what the metabolic products are. Yeast will absorb diacetyl and metabolise it by reducing the ketone groups to form acetoin and 2,3-butanediol, relatively flavorless compounds. But some reports say acetoin imparts a rather musty flavour.

All the safety workseems to concentrate on diacetyl exposure of the airways and lungs.

Incidentally Con Agra have just announced that they will change the recipe for its Orville Redenbacher and Act II brands over the next year to remove diacetyle as a flavouring chemical.

Obvously have taken note of Lord Patel. News reports about thias chnage by Con Agra carry quotes as follows..."The Flavour and Extract Manufacturers Association said diacetyl occurs naturally in foods such as butter, cheese and fruits, and has FDA approval for use as flavouring."


So if it occurs as a naturally occurring chemical it's OK then ?

Do not flagellate yourself you raised a good point. It is essential that eternal vigilance is maintained on what we are encouraged by food manufacturers to put in our mouths. I this instance with diacetyl in microwave popcorn we have induced sensible changes without the need to resport to legal threats - which is a major move. 6/9/07