September 5, 2007 The Pump Handle 13Comment

Last week, Pop Weaver announced that it was eliminating diacetyl from its microwave popcorn products. Today, the Seattle Post-Intelligencer and Associated Press report that ConAgra will remove diacetyl from its Orville Redenbacher and Act II microwave popcorn over the next year. This news comes as David Michaels’s post here about federal agencies’ inadequate response to a case of bronchiolitis obliterans in a popcorn consumer has attracted widespread media attention (e.g., from the Associated Press, Denver Post, and Milwaukee Journal-Sentinel).

It’s great to see that popcorn companies are responding to the problem of diacetyl, since federal agencies are reacting slowly and ineffectually. These announcements still prompt us to ask something we’ve asked before, though: What do Pop Weaver and ConAgra know about diacetyl exposure that the public doesn’t?

In particular, we’re concerned because it seems that the EPA has shared with ConAgra and Pop Weaver results of a study it conducted to measure the emissions from microwave popcorn. (The study does not deal with health effects related to the emissions, but it should be possible to compare emissions data with diacetyl measurements from manufacturing facilities where workers diagnosed with bronchiolitis obliterans were employed.) In a Seattle Post-Intelligencer article about Pop Weaver’s decision to drop diacetyl from its products, Andrew Schneider reports:

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.

Back in May, David Michaels reported on a 2004 letter from a Senior VP at ConAgra to EPA’s Assistant Administrator for the Office of Research and Development. The letter indicated not only that ConAgra knew about EPA’s research on diacetyl emissions but that the company had been conducting its own research and had developed a “Consumer Exposure Risk Index for butter flavors in microwave popcorn.”

So, why hasn’t the EPA shared the results of its study with the public? Andrew Schneider checked into the agency’s excuse:

But the industry already knows what the EPA found, according to George Gray, the current head of the EPA’s office of Research and Development. He told the P-I that the popcorn industry was given the opportunity to review the final results before the study was submitted for publication.

Gray said there was nothing improper in allowing the industry to review the findings, saying it was necessary to convince industry that none of their confidential business information, such as what the flavoring agents are and the construction of the popping bag, was released to the public.

Further, Gray said the information could not be released to other public health professionals because it would prevent his scientists from getting their work published in peer-reviewed journals.

However, most prominent medical and scientific journals said that exceptions are always made.

“We’re not going to punish researchers for disclosing information that is of vital interest to the public health,” said Karen Pedersen, manager of media relations for The New England Journal of Medicine.

Now that a case of bronchiolitis obliterans has been identified in a microwave popcorn consumer, even more people are concerned about their exposure to this widely consumed snack food. The EPA should release the results of its study immediately and show that at least one federal agency is capable of doing the right thing for public health.

Liz Borkowski works for the Project on Scientific Knowledge and Public Policy (SKAPP) at George Washington University’s School of Public Health and Health Services.

13 thoughts on “ConAgra Drops Diacetyl – and Prompts More Questions About Unreleased Research

  1. Diacetyl, !! its fairly new to my vocabulary. But, what I would really like to know is: Where else is this chemical found in our daily diet?
    1. Is it limited to junk food (because we know flavor is a mandatory criteria)?
    2. Is it applied to any “fresh” foods that we consume?

    I’m conviced that there are more food companies that should be coming foward with statements.

    I’m conviced that government looks after businesses first and consumers last!

  2. Just read the AP story and wanted to comment that movie theatres use this “flavoring” on their popcorn. The kettles (popcorn machines) use a butter flavored oil and a butter flavored salt when they pop corn. Wonder what the health impact on the employees is? How much of it is “in the air” at a theatre?

  3. Ray: Daicetyl occurs naturally in some foods, including butter and beer. As far as I know, only the effects of synthetic diacetyl have been studied – and it’s probably present in much higher concentrations when it’s used in manufacturing.

    So far, bronchiolitis obliterans cases have turned up among workers who manufacture flavorings and baked goods, as well as in microwave popcorn workers. I would not be surprised to learn of new cases involving additional food products.

    Sharon: I don’t know of any studies or case reports involving movie theater employees. Heat probably makes the diacetyl more volatile, so employees spending a lot of time near the pump dispensing the hot butter liquid may be inhaling it.

  4. Also note that Con Agra has only stated that it will stop using diacetyl in its popcorn. Diacetyl is used in a number of other food products. Will it continue to be used in non-popcorn applications?

  5. I just checked the ingredients list on my popcorn package. I eat a lot of the Orville 100-cal. bags. Listed ingredients are: popcorn, palm oil, salt canola oil, sucralose, TBHQ and citric acid.

    Is diacetyl in one of those ingredients, or could it be included in amounts too small to be listed?

  6. What compound and mechanisms are they actually describing with the term diacetyl? That sounds more like a radical which can be part of a larger molecule, and freed under some circumstances (eg, how heroin in some patients can more effectively cross select brain barriers than morphine, but then be stripped leaving in effect the same process as morphine alone in other patients for whom it’s effective alone).

    Is the risk here one of free reactive radicals, one of dust or irritants, or one of larger molecules with additional issues? Are we talking a single flavor chemical, or a family of synthetic flavors which share a common trait of inclusion of a diacetyl radical, or what?

  7. Donna: When an ingredients list includes “other natural and artificial flavors,” that’s the thing that makes me suspect diacetyl may be in it. Your best bet is probably to call the company – some companies will list an 800 number on the box – and ask if that product contains diacetyl. Now that this is in the news, companies should be preparing their customer service reps to answer that questions.

  8. Thank you, Liz. I just called ConAgra. The representative took the bar code number and reported that since butter is not in this particular product, no diacetyl is present. Other popcorn eaters of the 100-cal. mini Bags can feel better as I do.

  9. Thanks for the info Liz.

    Is there any easy summary of hard data as to what levels of exposure are linked to factory chemical handling practices which do or don’t comply with suggested negative pressure mixing room and respiratory protection guidelines, or of level of release in home situations?

    Do diacetyl release or inclusion levels from other foods listed in the NIH toxicology as using such flavoring agents pose any problem, including when orally ingested rather than vaporized and inhaled as with popcorn? Are oral ingestion levels from other foods adequately diluted as to cause no more problem than ketones present from natural cellular glucose metabolism, with realistic or suspect safe levels known?

    Has anyone studied levels in specific popcorn products, such as to determine if this flavor agent is used in higher or lower concentrations in low calorie versus “theater butter” simulation product versions? I’d suspect the low cal versions might have less flavor agents, though low fat or no-sugar foods of other types sometimes have surprises, like high salt, or alcohol sugars which may be worse than natural ones.

    It would seem that this home popcorn issue would be most significant in small kitchens in tightly air sealed residences, and minimal in larger or well ventilated kitchens? It also sounds like a good reason to go through the nuisance of operating one’s own air popper, even though those small bags are rather convenient and amazingly inexpensive relative to the amount of trash they generate.

    Two other families of chemicals which I suspect have contributed to some nasty progressive neurological diseases are boat antifouling paints, often pressure washed or sanded without much protection, and lacquer thinner, a mix of several rather aggressive VOC’s for which the simplest of skin protection requires dual layer gloves since it easily penetrates nearly all available single material barriers. Those both serve enough useful purposes difficult to accomplish otherwise that I’d hate to see them unavailable, yet carry risks that seem poorly understood by many users, including some otherwise highly educated ones. Is that the kind of issue your organization could convert to better public education or suggested safe use practice guidelines?

  10. Good questions, Loki, and I’m afraid I can’t answer all of them. I expect there would be more data on workplace exposures if OSHA were really moving forward on this, and of course FDA doesn’t seem to be working too hard on the consumer angle, which would include the different kinds of popcorn products you mention.

    NIOSH has been good about investigating workplaces where people have been diagnosed with bronchiolitis obliterans, and their reports are a good place to go if you want to see some examples of diacetyl concentrations from different workplaces with different controls (or lack thereof). We have a list of studies, including NIOSH reports, at

    Ventilation is important, as you suggest, and it’s one of the things NIOSH includes in its engineering controls recommendations. Now that it seems consumers might be at some risk, too, I will certainly open a window if I pop microwave popcorn at home!

    As far as educating people about the risks of particular products, I think people need to realize how much our federal agencies do – and how much they don’t do – to protect us from harmful substances. A lot of people seem to assume that something can’t be sold if it isn’t proven to be safe, but the reality is that we don’t even have basic toxicity information on many of the high production volume chemicals used or made in this country, and the EPA has to jump through a lot of hoops before it can require companies to test their chemicals.

  11. I work with Weaver Popcorn Company, and would like to clarify a couple of points:
    – Weaver Popcorn Company has ALREADY removed diacetyl from the flavoring in its microwave popcorn brands – Pop Weaver, sold at mass market retailers, discount stores and select grocery stores; and Trail’s End, sold through Boy Scout councils. Product with no diacetyl flavoring is already on store shelves.
    – Weaver has been working on this flavor reformulation for years, independent of the EPA study. This change was planned long before the company reviewed the study results; as soon as Weaver developed an alternative formulation that maintained a buttery flavor without containing diacetyl, the company made the change.
    – The reason that Weaver decided to reformulate its flavor to eliminate diacetyl was in response to growing consumer concern. Since popcorn is Weaver’s sole product, the company takes consumer perception very seriously. Consumers were growing more concerned about diacetyl, so the company made the industry leading move to take it out of its flavorings.

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