Slushies seem like harmless treats, especially in summer, but they often contain an additive that can make children sick. Glycerol, also listed on labels as E422 or glycerin, is used to keep slush drinks from freezing solid without loading them with sugar. It’s approved as a food additive across the U.S. and Europe.
At certain concentrations, however — and especially when consumed rapidly by small children — glycerol doesn’t just sweeten the treat. It throws off normal metabolic balance, dragging blood sugar to critically low levels, disturbing potassium levels and triggering a metabolic emergency.
What makes this more dangerous is how symptoms mirror inherited metabolic conditions. That leads to confusion in emergency departments and delays in appropriate treatment. Recent research revealed what’s really happening inside a child’s body during glycerol intoxication and how to avoid this serious condition.1
Slushies Sent Healthy Kids to the ER Within an Hour
A study published in Archives of Disease in Childhood looked at 21 cases of children in the U.K. and Ireland who got seriously sick shortly after drinking slushies.2 All of the children — mostly toddlers and preschoolers — were healthy beforehand and their symptoms often appeared within 60 minutes of sipping the drink.
• Children got sick fast after drinking slushies — Within an hour, almost every child had a drop in consciousness. The symptoms were so serious, doctors initially thought these kids might have rare genetic conditions that affect how the body turns food into energy.
• The common ingredient was glycerol — Every slush drink linked to these cases contained glycerol, which keeps the slush smooth without using much sugar. Even though glycerol is considered safe in small amounts, it caused major problems in these young children, as blood tests showed it was building up in the body.
Children also had low potassium and artificially high triglyceride levels, meaning their blood tests showed fat levels that didn’t match what was really there.
• Symptoms followed a clear pattern — Nearly all the children had dangerously low blood sugar. In most cases, it dropped below a level that can lead to coma or even death. Almost every child had acid buildup in the blood, and most had low potassium, which interferes with nerves and muscles. One child even had a seizure. Every urine test showed high levels of glycerol.
• One child got sick a second time after another slushie — Most of the children got better after they stopped drinking slushies. But one child had a repeat episode more than three years later after drinking another one. This time, the parents quickly gave a glucose drink and called for help. The symptoms faded before the child made it to the hospital, confirming that glycerol — not a disease — was to blame.
Why Children React So Strongly to Glycerol
Young children have less body mass, so a 500 milliliter (mL) (17 ounce) slushie contains way too much glycerol for them. Even a half-serving could be enough to cause harm. Drinking a slushie quickly — or while hungry or after exercise — makes the body even more vulnerable to a crash.
• The liver gets overwhelmed fast — Once glycerol enters your body, your liver has to process it. In children, especially those who haven’t eaten recently, this process doesn’t work as smoothly. The liver can’t keep up, and that leads to a rapid drop in blood sugar and a build-up of acid in the blood.
• Too much glycerol blocks your body’s backup fuel system — Normally, when you haven’t eaten in a while, your body makes its own glucose. Glycerol is supposed to feed into that system. But if there’s too much, the system gets jammed. The enzymes can’t keep up, and blood sugar tanks. Children may also have underdeveloped enzymes, making the reaction even worse.
• Glycerol interferes with brain pressure and electrolytes — Glycerol pulls water through cells, which is why it’s used in hospitals to reduce brain swelling in trauma patients. But that same effect causes problems in children, especially if fluid shifts interfere with potassium levels or increase pressure in the brain. This could explain the sudden drowsiness and seizures seen in some of the cases.
Avoid Slushies — Choose Healthier Alternatives Instead
If you’re a parent of a young child, especially under the age of 8, the best thing you can do right is eliminate slush ice drinks from your child’s routine. These colorful frozen treats not only typically contain high-fructose corn syrup, artificial colors and flavors, but if they contain glycerol — and most sugar-free or “no added sugar” versions do — they can cause a rapid, dangerous drop in blood sugar and trigger symptoms that mimic serious metabolic disorders.
Once you understand the mechanism behind what’s happening in your child’s body, the solution becomes clear: remove the cause and offer something better. Here’s what I recommend you do to protect your child’s health:
1. Stop buying slushies, especially the sugar-free ones — Glycerol is added to keep the slush consistency in sugar-free drinks, but it’s not safe for small children. Ingesting just 50 to 220 mL (1.7 to 7.4 ounces) of a slushie is enough to trigger severe symptoms in toddlers.3 If your child is under 8, their body weight is low enough that even a small amount of glycerol hits hard.
If you’re unsure whether a slush drink has glycerol, assume that it does unless the label specifically says otherwise. Many brands don’t list exact concentrations, so transparency is an issue. The safest choice is to avoid slushies entirely. Even if they don’t contain glycerol, most slushies are better off avoided.
2. Offer real-food treats that support blood sugar stability — Most children love sweet, cold treats — so give them alternatives that don’t destroy their metabolic balance. Blend fresh fruit with crushed ice or frozen mango cubes with coconut water.
You get sweetness, hydration and vitamins without the hidden risk of glycerol-induced low blood sugar. If your child is healing from any kind of blood sugar crash, real fruit and simple carbs like white rice or maple syrup in small amounts are far better choices than processed sugar-free treats. You’re giving their body fuel it recognizes and can use safely.
3. Make sure your child eats before consuming any sweet treat — If your child has been running around at a park or hasn’t eaten in several hours, their metabolic system is already working hard.
Dumping a slushie on top of an empty stomach magnifies the risk. If you do allow the occasional sweetened drink, always pair it with a meal or snack first. Even something as simple as a banana or a boiled egg beforehand creates a buffer that protects against sharp blood sugar crashes.
4. Teach your child to sip slowly, not chug — One thing that stood out in the research was how quickly children drank these slush drinks. When you consume glycerol too fast, your body doesn’t have time to process it properly.
For any treat — whether juice, smoothie or something frozen — teach your child to sip slowly. Set the tone by sharing it with them and modeling the behavior. Small, slow sips over time let their metabolism keep up and prevent the kind of overload that leads to glycerol intoxication.
5. Spread the word to other parents and caregivers — Most parents have no idea slushies are risky. Share what you now know with grandparents, babysitters, teachers and family friends. If someone’s watching your child, make it clear: no slushies, especially the ones labeled sugar-free or artificially sweetened. If your child has ever had an unexplained episode of low energy, confusion or vomiting after a frozen drink, now you know what could be to blame.
Educating the people around you helps prevent future incidents and makes your child’s environment safer wherever they go.
By removing the trigger and supporting your child’s natural metabolism with real food and smarter habits, you’re not just avoiding a one-time scare — you’re building long-term health.
FAQs About Glycerol in Slushies
Q: What ingredient in slushies is making kids sick?
A: Glycerol (also labeled as E422 or glycerin) is the ingredient responsible. It’s added to sugar-free slush ice drinks to keep them smooth and slushy, but in young children, it can trigger serious symptoms like unconsciousness, low blood sugar and seizures.
Q: How quickly do symptoms appear after drinking a slushie with glycerol?
A: Symptoms usually appear within 60 minutes of consumption. Most children in the study became drowsy, confused or unresponsive shortly after drinking a slushie, especially if they hadn’t eaten recently or had been physically active.
Q: What are the signs of glycerol intoxication in children?
A: Key symptoms include decreased consciousness, low blood sugar, acid buildup in the blood, low potassium, high triglyceride readings and sometimes seizures. These symptoms mimic rare genetic disorders.
Q: Is this a one-time issue or does it keep happening?
A: In the majority of cases, the illness didn’t return once the child stopped drinking slushies. However, one child who drank another slushie years later had symptoms return almost immediately — confirming that glycerol was the trigger.
Q: What’s the safest way to protect my child?
A: Avoid giving your child slush ice drinks entirely, especially sugar-free versions. Offer real-food alternatives like frozen fruit smoothies instead.
