Grapes: Pesticides and the Choking Hazard

Table of Contents

1. Why a Grape Is the Worst Possible Shape
2. What the Paediatric Record Shows
3. The Fix: Quarter Them Lengthwise
4. The Rest of the List, and What to Do
5. Grapes and the "Dirty Dozen"
6. What the Peer-Reviewed Critiques Found
7. Does Buying Organic Help?
8. The Comparison That Should Anchor the Decision
9. Washing: What Works and What Does Not
10. Grapes Are Genuinely Dangerous to Dogs
11. Other Practical Cautions
12. Key Research Papers
13. Connections
14. Featured Videos

Why a Grape Is the Worst Possible Shape

A young child's airway is narrow — roughly the diameter of their own little finger — and it is not a rigid tube. Children under about five also have immature chewing and swallowing coordination, few or no molars for grinding, and a strong tendency to talk, laugh, run and be startled while eating. Any object that can reach the larynx before being chewed can lodge there.

A whole grape is close to the worst-case object, and it is worth spelling out why, because the reasons also identify every other food on the same list.

• It is almost exactly the right size. A grape is comparable in diameter to a small child's airway. Slightly smaller and it would pass; slightly larger and it could not enter.
• It is round, so it seals. An irregular object leaves gaps that air can move through. A sphere in a cylinder forms a complete plug, and no air moves at all.
• It is smooth and slippery. The waxy skin means it slides past the tongue and into the throat before a child registers that it has not been chewed.
• It is soft and compressible — which makes it worse, not better. This is the counter-intuitive part. A firm object may sit loosely; a soft one deforms to the shape of the airway, wedges itself in and forms a tighter seal. Its softness also makes it far harder to dislodge with back blows or abdominal thrusts, and difficult for a clinician to grasp with forceps.

Deaths from choking are a major cause of childhood mortality, especially in the very young, and as the Aberdeen emergency physicians who wrote about this put it, whole grapes are "ideally suited to cause paediatric airway obstruction".

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What the Paediatric Record Shows

This is not a theoretical risk raised by cautious people. It is documented in the clinical literature and in national paediatric guidance.

Lumsden and Cooper, emergency physicians at Aberdeen Royal Infirmary, published a short paper in Archives of Disease in Childhood in 2017 under the title "The choking hazard of grapes: a plea for awareness". They described three children who presented to their department after grape aspiration, and their central observation was not about the mechanism — which is obvious once stated — but about awareness. Although grapes are regularly implicated in paediatric choking, they wrote, knowledge that this popular fruit and other similarly shaped foods pose a choking hazard is not widespread. They argued for wider dissemination among health professionals working with children. The fact that a case report in a major paediatric journal was needed to make this point tells you how far the message has travelled.

The American Academy of Pediatrics, through its Committee on Injury, Violence, and Poison Prevention, published a policy statement on the prevention of choking among children in Pediatrics in 2010, which sets out the food characteristics that make choking likely — round, cylindrical, compressible, smooth, slippery — and names the specific foods that combine them. Grapes and hot dogs are the archetypes. Canadian paediatric guidance, summarised by Cyr in Paediatrics & Child Health in 2012, makes the same points about prevention.

The consistent theme across all of it is that this is a preventable injury, and that the prevention is trivial.

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The Fix: Quarter Them Lengthwise

Here is the practical rule, and it is worth memorising exactly.

For children under about five, cut grapes lengthwise into quarters — not crosswise into discs.

The direction of the cut is the entire point and it is the part people get wrong. Slice a grape crosswise and you produce round discs, which are still circular in cross-section and can still form a seal. Cut it lengthwise, twice, and every piece is a long thin wedge with no round profile in any orientation. A wedge cannot plug a tube.

Some practical notes:

• Halving lengthwise is better than nothing but is not enough for the youngest children. A lengthwise half of a large grape can still be wide enough to obstruct a toddler's airway. Quarters are the standard advice.
• The same applies to cherry and grape tomatoes, which have identical geometry, and to mozzarella balls, olives and large blueberries.
• Keep doing it longer than feels necessary. Guidance generally extends to about age five; children develop molars and safe chewing at different rates, and there is no cost to continuing.
• Supervise eating, and insist on sitting still. Most choking incidents involve a child eating while moving, playing, laughing or lying down. A child should eat sitting up, at a table, with an adult present.
• Tell everyone who feeds the child. Grandparents, childminders, nursery staff, older siblings, party hosts. This information does not spread on its own — that was the whole point of the Aberdeen paper.
• Do not rely on removing the skin. A peeled grape is more slippery, not less dangerous. Cut it.

It is worth learning paediatric choking first aid — back blows and chest or abdominal thrusts appropriate to the child's age — from a proper hands-on course rather than from any web page, this one included. A soft, wedged grape is notoriously difficult to dislodge, which is another reason prevention is so much better than response.

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The Rest of the List, and What to Do

Once you can see the pattern — round, smooth, compressible, airway-sized — you can identify the hazards yourself. The commonly named ones for young children are:

• Whole grapes, cherry tomatoes, cherries, large berries and olives — quarter them lengthwise; remove stones.
• Hot dogs and sausages — the classic worst case, a compressible cylinder of exactly airway diameter. Cut lengthwise first, then into small pieces.
• Whole nuts — hard, irregular, impossible for a child without molars to grind. Not before about four; nut butters spread thinly are fine.
• Raw carrot rounds, apple chunks and other hard raw pieces — grate, or cook until soft, or cut into thin strips rather than coins.
• Popcorn, hard sweets, chewing gum and marshmallows — not for the youngest children at all.
• Large blobs of thick nut butter — can adhere to the palate and throat; spread thinly, never eaten by the spoonful.

None of this is a reason to keep fruit away from children. Grapes are a good food for a child, and cut correctly they are entirely safe. The point is that the preparation is not optional.

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Grapes and the "Dirty Dozen"

Now to the question that gets far more attention.

Each year the Environmental Working Group, a US environmental advocacy organisation, publishes a "Shopper's Guide to Pesticides in Produce" ranking fruits and vegetables by pesticide residue. The twelve worst become the Dirty Dozen; the cleanest become the Clean Fifteen. Grapes have appeared on the Dirty Dozen consistently for many years, and imported table grapes typically rank among the produce items with the largest number of distinct residues detected.

That basic fact is not in dispute, and it deserves to be stated plainly rather than dismissed. Table grapes are a high-input crop. Vines are vulnerable to powdery mildew, downy mildew, botrytis bunch rot, mealybugs, mites and leafhoppers, so vineyards are sprayed repeatedly through a season. The fruit has a thin, waxy, absorbent skin, it is not peeled before eating, and its tight clusters trap spray residue in places that are hard to rinse. Multi-residue testing of table grapes routinely detects several different fungicides and insecticides on a single sample.

The Environmental Working Group draws its data from a legitimate source: the USDA Pesticide Data Program, a large annual federal residue-monitoring programme whose results are public. Where the disagreement lies is not in the measurements but in what the ranking means and what a shopper should do about it.

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What the Peer-Reviewed Critiques Found

The most-cited scientific analysis of the Dirty Dozen is Winter and Katz, published in the Journal of Toxicology in 2011. It is worth walking through carefully, because it is quantitative and because its findings are rarely reported alongside the list itself.

The authors took the same USDA Pesticide Data Program data and did something the ranking does not do: they calculated actual consumer exposure, using probabilistic modelling of how much of each commodity people eat, and compared it with the chronic reference dose for each pesticide — the daily exposure a regulator considers to carry no appreciable risk over a lifetime, itself set with large safety factors below the level where no effect is seen in animal studies. They ran this for the ten most frequently detected residues on each of the twelve commodities, giving 120 estimates.

Their results:

• All 120 exposure estimates were well below the chronic reference dose.
• Only one of the 120 exceeded 1% of the reference dose — methamidophos on bell peppers, at 2%.
• Only seven estimates (5.8%) exceeded even 0.1% of the reference dose.
• Three quarters of the combinations came in below 0.01% of the reference dose — which the authors note corresponds to exposures a million times below the levels at which no adverse effect is observed in animal toxicology studies.
• Over 40% were below 0.001% of the reference dose.

Their three conclusions were that exposures to the most commonly detected pesticides on these twelve commodities pose negligible risk to consumers; that substituting organic forms of the twelve for conventional forms does not appreciably reduce consumer risk; and — the sharpest of the three — that the methodology used to rank commodities by pesticide risk "lacks scientific credibility".

The methodological objection is the substantive one. The ranking is built largely on the frequency and number of residues detected, not on how toxic each residue is or how much of it is present. Detection technology has improved enormously; instruments now find residues at parts per billion that were invisible twenty years ago. A food can therefore rise up such a ranking because six different compounds were each detected at a thousandth of the level of regulatory concern, while a food with one residue closer to the limit ranks lower. Winter developed this argument further in the International Journal of Food Contamination in 2015, examining chronic dietary pesticide exposure across the American diet.

Two things should be said in fairness on the other side. Reference doses are set one compound at a time, and the question of cumulative exposure to mixtures is a real and unresolved area of regulatory science — European regulators have been developing cumulative risk assessment methods for exactly this reason, and the annual EFSA reports on pesticide residues in food discuss it. And people with occupational or residential exposure to agricultural spraying face an entirely different situation from a shopper eating a bunch of grapes; nothing here applies to farmworker exposure, which is a genuine and serious public-health issue in its own right. See our page on pesticides for that wider picture.

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Does Buying Organic Help?

Partly, and less than most people expect.

Smith-Spangler and colleagues published a systematic review in Annals of Internal Medicine in 2012 asking whether organic foods are safer or healthier than conventional alternatives. On residues, organic produce carries detectable synthetic pesticide residues considerably less often. On nutrients, the review found little difference of consequence. On health outcomes, the evidence was insufficient to show that eating organic makes people healthier — which is not the same as showing it does not, but is where the evidence stood.

Three points make this less decisive than it sounds:

1. Organic farming uses pesticides too — approved substances of natural origin, including copper compounds, sulfur, spinosad and pyrethrins. "Organic" means a different list of permitted inputs, not an absence of pest control. Copper fungicide, heavily used in organic viticulture, accumulates in soil and is not benign.
2. If conventional exposure is already three to six orders of magnitude below the level of concern, reducing it further has little room to matter, which is precisely what Winter and Katz argued.
3. Cost matters, and it is a health variable. If organic grapes cost three times as much and the result is that a family buys less fruit, the substitution has made things worse rather than better.

The reasonable position: buy organic grapes if you can afford them and prefer to, and do not feel you must. There are decent reasons to choose organic that have nothing to do with your own residue exposure — farmworker safety, water contamination, soil biology, biodiversity — and those arguments stand on their own merits. What the evidence does not support is treating conventional grapes as dangerous.

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The Comparison That Should Anchor the Decision

One study puts the whole question in proportion better than any other. Reiss and colleagues, writing in Food and Chemical Toxicology in 2012, asked a directly practical question: if half the US population ate one more serving of fruit and one more of vegetables per day, how many cancer cases would be prevented — and how many might theoretically be caused by the extra pesticide residue that came with them?

They estimated the prevention side from a published meta-analysis of nutritional epidemiology, and the risk side using EPA methodology, cancer potency estimates from rodent bioassays and USDA residue sampling data. Their answer: approximately 20,000 cancer cases per year prevented, against up to 10 cancer cases per year potentially caused by the added pesticide intake.

The authors were candid about the uncertainties — residual confounding in observational fruit-and-vegetable epidemiology is a well-known problem, and extrapolating human cancer risk from high-dose rodent bioassays is contested in both directions. It is also worth knowing that the analysis came from a scientific consultancy that works for industry clients, which is a reason to read it critically rather than a reason to dismiss it. But the ratio here is not marginal. It is roughly two thousand to one, and no plausible correction to either estimate reverses the direction.

The conclusion that follows is the one worth carrying to the supermarket: the health risk of not eating the fruit is far larger than the health risk of the residue on it. If a residue ranking causes someone to eat fewer grapes, it has done net harm.

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Washing: What Works and What Does Not

Washing is worth doing, mostly for reasons that have nothing to do with pesticides — dirt, handling, and the bacterial contamination that causes real and immediate illness.

• Rinse under cold running water and rub the fruit with your hands. The mechanical action does most of the work. Do this even for organic grapes, and even for fruit you plan to peel.
• A short soak helps with clusters. Grapes are awkward because the fruit sits tightly packed on the stem. A few minutes in a bowl of water, agitated, then a rinse, reaches more surface than a quick pass under the tap.
• Commercial produce washes are not worth buying. Studies comparing them with plain water have generally found little added benefit. Water and friction are the active ingredients.
• Baking soda solution has some evidence behind it for removing certain surface residues from produce, and is cheap and harmless. Rinse thoroughly afterwards.
• Washing removes surface residue, not systemic residue. Some pesticides are taken up into the plant and distributed through its tissue; no amount of washing reaches those. This is a real limitation and it is why washing is a partial measure rather than a solution.
• Wash immediately before eating, not before storing. Wet grapes spoil and mould quickly. Keep them dry in the refrigerator and rinse the portion you are about to eat.
• Do not use soap, detergent or bleach on produce. They are not intended for food contact, they are absorbed by porous surfaces, and they cause more problems than they solve.

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Grapes Are Genuinely Dangerous to Dogs

This belongs on any grape safety page, because it is a real emergency and because the mechanism was only recently identified.

Grapes and raisins can cause acute kidney injury in dogs. The toxicity has been recognised clinically for decades, but it is unusual: some dogs eat grapes with no effect, others develop kidney failure after a small quantity, and no reliable toxic dose has ever been established. Schweighauser and colleagues described the clinical picture — acute kidney injury and neurological signs following grape or raisin ingestion — in the Journal of Veterinary Internal Medicine in 2020.

For years the responsible agent was unknown. In 2022 Wegenast and colleagues at the ASPCA Animal Poison Control Center published a case series in the Journal of Veterinary Emergency and Critical Care that made the connection. They described four dogs that developed acute kidney injury after eating tamarinds and two after eating cream of tartar — two substances with nothing in common with grapes except one thing: tartaric acid and its salt, potassium bitartrate. Clinical signs, laboratory findings and the changes seen at necropsy closely matched those of grape and raisin toxicosis. The authors identified tartaric acid as the likely toxic principle. Grapes are unusually rich in it, dogs appear to be unusually sensitive to it, and the wide variation in tartaric acid content between grape varieties and ripeness would explain why the toxic dose has never been pinned down. The outcomes in that series were poor: two dogs became anuric, one oliguric, and four were euthanised.

Practical rules:

• No grapes, raisins, sultanas or currants for dogs. Ever. Not as a treat, not as a training reward.
• Raisins are worse than grapes because the toxin is concentrated by drying, and because a dog can eat a great many quickly.
• Watch for the hidden sources — fruitcake, mince pies, hot cross buns, granola, trail mix, oatmeal cookies, and anything else on a low table at Christmas.
• If a dog eats any quantity, call a vet or an animal poison control line immediately. Do not wait for symptoms. Early decontamination and intravenous fluids are what changes the outcome, and in the published series treatment was delayed in every case.
• Cats and ferrets are also advised to avoid them, though the evidence base is much thinner than for dogs.

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Other Practical Cautions

• Food safety. Table grapes have been involved in foodborne illness outbreaks, as all fresh produce occasionally is. Wash them, keep them refrigerated, and discard any that are split, mouldy or leaking — damaged skin lets in both bacteria and mould.
• Mould and mycotoxins. Grapes are prone to grey mould, and mouldy grapes in a bunch should be removed rather than eaten around. Ochratoxin A, a mycotoxin regulated in dried vine fruit and wine, is the reason dried-fruit standards exist for it.
• Grapefruit is a different fruit. The famous interaction that affects statins, some blood-pressure drugs and many others is a property of grapefruit, not grapes. Grapes do not carry the furanocoumarins responsible. Confusing the two names is common and is worth clearing up.
• Anticoagulants and antiplatelet drugs. Grape polyphenols have mild antiplatelet activity, and grape seed extract supplements more so. Large habitual supplemental doses alongside warfarin, clopidogrel or similar are worth mentioning at a medication review, particularly before surgery.
• Sulfites in dried fruit. Golden raisins and sultanas are usually sulfured. Most people are unaffected; a minority, including some people with asthma, are sensitive. Dark, sun-dried raisins are typically unsulfured.
• Fructose intolerance and IBS. Grapes and especially raisins are relatively high in fructose and are restricted on a low-FODMAP protocol. If grapes reliably cause bloating or pain, that is a plausible reason and not something to push through.
• Kidney disease. Grapes and raisins are a good potassium source, which is usually an advantage. For anyone on a potassium-restricted diet for advanced kidney disease, raisins in particular are concentrated enough to matter.

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Key Research Papers

1. Lumsden AJ, Cooper JG. The choking hazard of grapes: a plea for awareness. Archives of Disease in Childhood. 2017;102(5):473–474. — doi:10.1136/archdischild-2016-311750
2. Committee on Injury, Violence, and Poison Prevention. Prevention of choking among children. Pediatrics. 2010;125(3):601–607. — doi:10.1542/peds.2009-2862
3. Cyr C. Preventing choking and suffocation in children. Paediatrics & Child Health. 2012;17(2):91–92. — doi:10.1093/pch/17.2.91
4. Winter CK, Katz JM. Dietary exposure to pesticide residues from commodities alleged to contain the highest contamination levels. Journal of Toxicology. 2011;2011:589674. — doi:10.1155/2011/589674
5. Winter CK. Chronic dietary exposure to pesticide residues in the United States. International Journal of Food Contamination. 2015;2:11. — doi:10.1186/s40550-015-0018-y
6. Reiss R, Johnston J, Tucker K, DeSesso JM, Keen CL. Estimation of cancer risks and benefits associated with a potential increased consumption of fruits and vegetables. Food and Chemical Toxicology. 2012;50(12):4421–4427. — doi:10.1016/j.fct.2012.08.055
7. Smith-Spangler C, Brandeau ML, Hunter GE, et al. Are organic foods safer or healthier than conventional alternatives? A systematic review. Annals of Internal Medicine. 2012;157(5):348–366. — doi:10.7326/0003-4819-157-5-201209040-00007
8. European Food Safety Authority, Medina-Pastor P, Triacchini G. The 2018 European Union report on pesticide residues in food. EFSA Journal. 2020;18(4):e06057. — doi:10.2903/j.efsa.2020.6057
9. Wegenast CA, Meadows ID, Anderson RE, Southard T, González Barrientos CR, Wismer TA. Acute kidney injury in dogs following ingestion of cream of tartar and tamarinds and the connection to tartaric acid as the proposed toxic principle in grapes and raisins. Journal of Veterinary Emergency and Critical Care. 2022;32(6):812–816. — doi:10.1111/vec.13234
10. Schweighauser A, Henke D, Oevermann A, Gurtner C, Francey T. Toxicosis with grapes or raisins causing acute kidney injury and neurological signs in dogs. Journal of Veterinary Internal Medicine. 2020;34(5):1957–1966. — doi:10.1111/jvim.15884
11. Bates N, Tizzard Z, Edwards N. Acute kidney injury in dogs following ingestion of cream of tartar and tamarinds and the connection to tartaric acid as the proposed toxic principle in grapes and raisins (correspondence). Journal of Veterinary Emergency and Critical Care. 2023;33(6):722–723. — doi:10.1111/vec.13349
12. Primary data source — the USDA Pesticide Data Program annual residue monitoring results: USDA Agricultural Marketing Service: Pesticide Data Program
13. Live literature search — paediatric food choking prevention: PubMed: paediatric food choking prevention
14. Live literature search — dietary pesticide residue risk assessment: PubMed: dietary pesticide residue risk assessment

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Connections

• Grapes — the main topic page.
• Grapes — Benefits Deep Dive — the hub for this set of articles.
• Raisins, Blood Sugar and Teeth — sulfites, portions and the dried form.
• Polyphenols and Vascular Health — the reason to keep eating them.
• Pesticides in Our Food — the wider picture, including occupational exposure.
• Glyphosate — the most contested individual pesticide.
• All Toxins — the complete index.
• Strawberries and Apples — other perennial members of the same residue list.
• Blueberries — another round fruit worth halving for very young children.
• All Food — the complete food index.
• Grapes: History and Origins — including why vineyards need so much spraying.
• Lab Tests — kidney function testing, relevant to the veterinary section above.

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