Chlorpropham on Sweet Potatoes

Sweet potatoThere’s no argument about it. The video on YouTube has impact. The curtain goes up on a sweet little girl who is preparing to share with us the results of a science experiment that was supposedly suggested by her grandmother. She shares the spotlight with three sweet potatoes that have been immersed in water to see how they would sprout. The results are dramatic. The sweet potato purchased in a conventional grocery store failed to sprout even after weeks, while the organic potato purchased in the same store produced some scrawny vines. But it was the sweet potato bought in a store that specialized in “organic” produce that steals the show. It practically grew a forest of vines. How could this be?

The produce manager in the supermarket had an explanation. Conventional sweet potatoes are sprayed with a chemical called chlorpropham to prevent sprouting. The organic ones in the supermarket may have picked up some of the chemical by cross contamination while the potato from the organic market was free of the chemical. “Chlorpropham can kill animals that they have tested it on. It can also cause tumours,” our little host informs us. She goes on to say that “with all of the chemicals, it is no wonder so many people are getting diagnosed with cancer.” The video ends with the rhetorical question “which potato would you rather eat,” and an ear to ear smile? Point made. Stay away from conventionally grown sweet potatoes because they harbor toxic chemicals.

There’s no way to know how this video really came about. Is it just an interesting little science fair project as it seems, or is there some other agenda? Did someone want to promote an organic philosophy either for economic or ideologic reasons? Let’s explore the real science here. Sweet potatoes are indeed sprayed with chlorpropham, or Bud Nip as it is commercially known. That’s because sprouting is not a good thing. When the sweet potato sprouts nutrients flood into the sprouts and cause the tuber to wither. Of course there is an economic angle here as well. By preventing sprouting, chlorpropham extends the shelf life of sweet potatoes.

But what about the claims of this chemical killing test animals and causing tumours? Yes, that happens at monstrous doses. Almost any chemical tested will cause some catastrophe at some dose. That’s why regulatory agencies determine the maximum dose at which no effect is seen in test animals known as the No Observed Adverse Effect Level, or NOAEL, divide this by an added safety factor of usually one hundred and come up with a dose to which people can be regularly exposed without consequence. But regulatory agencies also require ground water testing, effect on fish, effect on livestock, effect on workers who are exposed to the chemical and documentation about residues on produce. The process to “register” a chemical for agricultural use is not a haphazard one. A great deal of work goes into determining safe levels for humans. And the amounts found on sweet potatoes are way below any level that would pose a danger. So our little friend’s demonstration really shows the effectiveness of a chemical at preventing sprouting in order to improve the quality of a sweet potato rather than some sort of implied danger from eating conventional sweet potatoes.

39 responses to “Chlorpropham on Sweet Potatoes”

  1. Joe Schwarcz says:

    Liz Alber clearly demonstrates her scientific expertise with the comment:
    “Chemicals do not belong on our food nor in our bodies!”

    Hmm…a vacuum isn’t very tasty

  2. Malve says:

    If I can choose between eating a chemical or eating a fresh product without chemical treatment i choose the second one! And i don’t want to give chlorpropham to my little baby. What is wrong about promoting an organic philosophy either for economic or ideologic reasons? the less chemical we spread around, the better for the planet. The writer of this blog should think another time a bit further than his tip of the nose….

  3. Jessie says:

    Why is anything being tested on animals?

  4. Marc Landry says:

    What ignorance, and from a University!
    Toxins are safe in small doses if they help people make money?

    You compost the bad ones, you poor morons

  5. SEE says:

    If the world has gotten so populated that we need to use chemicals to preserve food to feed the masses then we might think about having fewer babies. At the rate we are going we will eventually starve despite the chemical efforts to feed us and human race will become extinct. Also a good idea to stop building communities on prime farmland.

    • Dnorts says:

      Here’s the thing. Population control is ridiculous. There are many European countries who are now paying women to have babies because their birth rate IS NO LONGER SUSTAINABLE for a population!!!! Ie, if they don’t have more babies, they will soon be withering or conquered nations. In the US, the baby boomers are going into the last leg of the race. In 30 years there may be no unemployment problem because they’ll all be dead. But everyone on welfare will have forgotten how to work, so then what?

    • miles says:

      This is just a band aid to the problem we dont have to use chemicals if we didnt say that all of one type of fruit or vegetable needs to be grown in one state by one company to feed everyone. Just like you might have a issue with saying kids need to be taught in school one way. We have to be open to the idea that your government or who ever you have in power are going to hand it all to you. People use to have to grow all there own vegetables and fruit or traid with the other local farmers. We die for convenience today. that is the price we pay and that makes us stupid!

    • Jimmy Ingersoll says:

      Something to think about: Ever see a movie called, “Soilent Green?” It was a movie about facing a world-wide lack of food and how governments chose to deal with it. It also brought in a concept that has never been addressed in reality throughout humanity. The movie solves two problems at once.
      In today’s world, we have no problem taking action and controlling the birth rate of people through contraceptives, operations, abortions, etc., but would NEVER consider controlling the death rate. WHY is that?

  6. Ag companies have chosen to follow the demand for beautiful, consistent produce which requires chemicals rather than educate the public to have reasonable expectations. There is no doubt that the accumulation of exposure to chemicals is the culprit – not one serving. Besides, maximum exposure levels are determined for healthy 180 pound males, not growing children or anyone with compromised health. Increasing profits is understandable but doing so by misleading the public or exposing them to harm is criminal. Purchasing organic is an educated choice.

    • Tom says:


      What you say about the test subjects may be true is some cases but the EPA sites studies for Chlorpropham that were conducted on adult females and children. These studies indicated that there were no negative effects from the low doses that were found in the environment or on potatoes.

  7. Liz Alber says:

    Eeeeeeeeew! Nature!! Get it off my vegetables!!! What an ignorant piece of garbage we’re being fed here. Find a local organic market and spend your money there. It’s as easy as that! Better yet join a CSA. They’re everywhere nowadays. Chemicals do not belong on our food nor in our bodies!

    • Jimmy Ingersoll says:

      I’m confused by the first part of your comment.
      Eeeeeeeeew! Nature!! Get it off my vegetables!!!
      What an ignorant piece of garbage we’re being fed here.

      Do you like the video or not? The wording in your comment makes me believe that by viewing the video you were being fed an ignorant piece of garbage.

      Are you asking Nature to get off your vegetables? ? ? Sorry, but that’s the impression you are leaving with readers.

  8. me says:

    “So our little friend’s demonstration really shows the effectiveness of a chemical at preventing sprouting in order to improve the quality ” How exactly does it improve the”quality”? does it taste better? I would argue that it’s quality is being judged here by it’s ability to fit into the current paradigm with regard to food growth and distribution and not what’s optimal for human consumption. Eat local, in season. Eat food in it’s natural state. And be less concerned about what unknown future consequences may or may not affect the complex human body. At the same time support your local farming community. win win.

  9. ugottabkidding says:

    anyone who’s been around and following health and food issues for long periods should realize that the testing they claim is safe can not possibly cover for long term results from built up accumulation of toxic chemicals. It’s been well documented that the chemical promoters coverup and lie to the public of the truth. Our hospitals are filled with victims of gross neglegence all for the sake of profit, ie. progress. These astronomical illnesses that sprung up over the past span of approx. 18 years coincide with widespread use of chemicals and gmo produce. you can’t ignore what is right before your eyes.

  10. Skip King says:

    Storing and displaying potatoes at 15°C (60°F) seems simple enough. If one were energy aware one might suggest the potatoes be stored at the appropriate temperature not the entire store.

    • Chris says:

      Cigarettes are not bad for you, DDT is not dad for you, Agent orange is not bad for you. etc., etc.,
      Big Pharma & Agribusiness exert undue influence on the people who create the regulations.


  11. marjo says:

    thanks maya Pinion, for your excellent reply, very informative

  12. Debbie says:

    I realize that much of what was said by McGill writer is true, I also realize that McGill is a school that teaches agriculture with chemicals and that McGill receives money from companies that produce chemicals. Therefore anything coming from this blog is slanted in favor of agriculture with chemicals, rather than organic farming. Also to deliver fresher potatoes should not cause increased trucks on the road if the same amount of potatoes were being delivered overall, or at least this would be true in large cities.

  13. Mike J says:

    Simple fix…


    • Toni says:

      Really… Live plants SPROUT… I’ve had three family members die of cancer….

      Please do not try to discount this child or make her to look criminal…

      Those who spray toxic chemicals on fruit and vegetables are the criminals…

      They should be charged, the companies supplying and making the chemicals should be held accountable…

      This needs to stop, end… we do not need chemicals on everything, so the major corporations can make more more and more profits.

      We (consumers) should be able to go to a grocery store and buy produce, without wondering what toxic crap is in it or on it…

      I do not care what the excuses are, it just needs to end.

      Shame on your company for trying to make a little girl look criminal and suspect.

      You and your company trying to divert attention to the toxic crap to increase profits needs to end….

      • Tamika says:

        I am sorry for the loss of your family members. I, too, have had family members die of various cancers. So far as I’m aware, none of them ate lots of sweet potatoes. Did your?

        • tom says:

          Tamika, your family members may not have eaten lots of sweet potatoes but they probably did eat root vegatables such as potatoes and carrots. Potato chips would also count. Something to think about.

        • Amy says:

          If you paid ANY attention to the video or the report from the University you would know that it is not just sprayed on sweet potatoes. This is only one of the MANY chemicals that is sprayed on your food and let’s not forget what they do to the food at the genetics lab.

      • Todd says:

        “Shame on your company for trying to make a little girl look criminal and suspect.”

        She is not the suspect. Whomever filmed this is suspect. Your response is exactly why they used a little girl. You provided the perfect knee jerk response they are hoping for.

  14. Leith Chu says:

    If a supermarket was kept at 15 degrees Celsius, the store would be getting constant complaints about the temperature.

    • Eva Vadenmark says:

      Not the store but the potatoes. And above temperature, they are now a days also store in daylight often i plastic bags, that produce solanin in the potatoes. Which is a no good substance for us to get in our bodies. So much knowledge that it scarified for convenience reasons. Sad to experience.

    • hanna says:

      Eh, you can’t think of another way than keeping the entire store at that temperature? You do know that they sell milk that they store even colder, right?

  15. Chris Aram says:

    Why are they spending so much research time and money to give vegetables a longer shelf life, except with the aim of increasing profits? Do we really know enough about nature to know what we are meddling with long term? Surely vegetables bought and eaten fresh don’t need any adulteration? What’s wrong with putting more effort into improving delivery and distribution to ensure a fresh product instead of making an old one last longer with worrying chemicals?

    • Maya Pinion says:

      Q1: Why are they spending so much research time and money to give vegetables a longer shelf life, except with the aim of increasing profits?
      A1: Increase proffits, yes; but there are other reasons. a) Certainly the most important is To Feed the Masses. More food for more people. b) you prevent spoilage. b) Increased spoilage means increased production and increased cost per unit eaten. c) Decreased shipping costs per unit eaten. This all translates not only into increased profits, but decreased prices to the consumer.
      Q2: Do we really know enough about nature to know what we are meddling with long term?
      A2: No. That is why we do research. Expensive, long drawn out research. The flip side is that if we did not meddle, we would not be able to feed the citizens of the earth. Famine would be rampant. Starvation would slowly kill millions upon millions. One can talk about the benefits of organic gardening all he wishes, but there are 7+ billion of us, the vast majority of whom do not have access to, let alone resources to buy or grow, organic food. Many of us are willing to take our chances of the possibility of cancer in 30 years versus the certainty of starvation in a month. Most of us do not have the choice; we must.
      Q3: Surely vegetables bought and eaten fresh do not need any adulteration?
      A4: Realize that adulteration is a relative term that means washing, chilling, heating, cooking, seasoning, salting, flavoring, freezing, fortifying, preserving… Not many of us have the desire, let alone ability, to walk into our garden, yank an onion out of the earth and eat it. Most of us do something. Those with less money, land, resources, proximity to fields, etc., rely on science and economics more than sunshine to eat.
      Q4: What’s wrong with putting more effort into improving delivery and distribution to ensure a fresh product instead of making an old one last laonger with worrying chemicals?
      A4: That is one part of a good strategy, but tomorrow you will be complaining about all of the trucks on the highway, all the trains you have to stop for, building a new expressway 15 miles south of your house, vehicular pollution, eating locally, ad infinitum. We choose our battles, and there is always someone willing to fight and tell me what to eat, where to get it, and how it should be grown. Rabid raccoons feast at the local landfill, then urinate, defecate, and nibble on your organic vegetables. If you wish to eat those instead store-bought sweet potatoes, enjoy. But realize this: your worry is self inflicted, and that guy down the street that is suffering from some strain of cancer that has unknown origins but you prefer to believe may have been induced by garden chemicals has not gone hungry or starved to death for over 7 decades.

      • Tina says:

        This was a brilliant reply. Really appreciate it!

      • Mike says:

        Really?? “Rabid raccoons feast at the local landfill, then urinate, defecate, and nibble on your organic vegetables. If you wish to eat those instead store-bought sweet potatoes, enjoy.”
        1. Why would those raccoons only visit organic vegetable gardens?
        2. Are “store-bought” sweet potatoes manufactured in some sanitized stainless steel factory, away from nasty things like soil, fertilizers, rain (who knows where that’s been?), sun, wind and groundwater?
        3. Do you wash your produce, store-bought or organic? Why or why not?

      • me says:

        A1: NOT TRUE. this is a ruse. I work at an organic farm. There is so much abundance. They can’t sell all of the fresh produce. They end up donating a bunch to the local food bank and there is still food left that’s simply thrown away. this isn’t about “feeding the masses” buy local. seasonal produce. eat it before it spoils. this is how nature intended. the only reason to be concerned with “spoilage” is to have a longer window for sale. a longer window for transportation. this allows for a model of food production that allows huge farms to undercut smaller local farms. This stifles the local economy. Provides an inferior product. AND ultimately creates a more fragile environment for people. IE: if something happens with transportation or production at the mega farm then there is no other option because the local farms are gone. Local farms feed the local community with seasonal produce. the way nature intended. That’s how you “feed the masses”

      • Ildi says:

        Dear Maya,
        Unfortunately you are misled (as most of the world) to believe that organic agriculture would not produce enough food to feed the world.
        Read: Badgley, et al. (2006) Organic agriculture and the global food supply, or Stanhill (1990)The comparative productivity of organic agriculture – only two examples of the vast literature showing that organic yields can be as good if not better than non-organic

        There are two things we also forget about:
        1) Western society throws away half of their food – which would already feed the global south. Shame on us! (Yes sources are out there for this two – do the research)
        2) The reason behind ongoing promotion of non-organic farming is to ‘benefit our economy.’ What would the agro-industry do if we no longer buy their chemicals?

        Finally one thing we EPA and other federal agencies forget to test for is the interactions of the zillions of chemicals we ingest with our foods. All these toxins are tested on their own – yet when we get exposed, we are generally ingesting at least 2-3 of them if not more.

      • Cory S says:

        I don’t know who you are Maya Pinon, but you are awesome.

  16. David Wees says:

    We have been conducting research on sweet potato production at the Macdonald Campus for the past year or so. Although we have not treated any of our sweet potatoes with chlorporpham (or any other anti-sprouting agent), very few of them sprouted until we put them in a warm greenhouse. Sweet potatoes stored at temperatures of about 15°C will not sprout for several months. They generally only start sprouting if kept warm (20° and above).

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