Glycerol may be dangerous to children. A recent update from the UK’s Food Standards Agency (FSA) warned that the sweetener was not suitable for those under seven when found in ice slush drinks.
The FSA reported several recent incidents of intoxication linked to glycerol. It is dangerous to children of lower-than-average body weight, the FSA suggests, and this has been converted to age, since body weights vary.
Glycerol is used as a sugar substitute in ice slush drinks to prevent them from freezing solid. The FSA advises businesses only to add it at the amounts necessary to achieve this effect.
“In the warm weather, children may be more likely to consume slush ice drinks containing glycerol, so it’s important that parents and carers are aware of the risks,” says FSA Chair Professor Susan Jebb.
“As a precaution, the FSA is recommending that children under seven do not consume slush ice drinks containing glycerol.”
According to the FSA, while glycerol can pose a risk at sufficient quantities in any food, slush ice drinks are where these sufficient quantities are most often found.
What is glycerol?
Glycerol, also known as glycerin, is a sugar alcohol, commonly used in food as a sweetener, solvent, or thickening agent.
It is often used in processed foods, such as tortilla wraps, icing, chewing gum, cereal bars, and, of course, slush drinks.
As a commercial food additive, it is known as E422 under regulation by the European Food Standards Agency (EFSA).
Glycerol is permitted for use in both the UK and the EU, although there are some concerns around its use in certain cases.
How dangerous is glycerol?
Some evidence points to glycerol being dangerous. Symptoms of mild glycerol intoxication include feeling sick and headaches, although these symptoms could be exacerbated by dehydration and exercise, as they are often recorded at play centres and trampoline parks.
Consumed at sufficient enough quantities, glycerol can cause low blood sugars levels and unconsciousness in young children.
Severe cases have been seen. In the UK in the past three years, there have been nine cases of hospitalisation of young children after they consumed slush drinks containing glycerol (with a further seven potential cases, seen in the media but not formally reported to the FSA).
Cases of intoxication from slush drinks are rare, about one in every 10m servings (there are 40-50m servings consumed in the UK each year).
The FSA speculates that the UK’s soft drinks levy may have led to reformulation of slush drinks, meaning sugar is replaced by glycerol.
The current FSA assessment concluded that there is a particular risk to children under seven with lower-than-average body weights, although idiosyncratic reactions in children of any age can’t be ruled out.
Studies used in the assessment found a wide range of threshold required to produce a physiological reaction, ranging from 125mg/kg body weight to >1000 mg/kg body weight.
The more conservative end would imply most children and even adults would exceed the recommended amount after a single serving of slushy drinks. Given the rarity of cases even in children, however, the FSA concluded that this was unlikely.
Alongside slush ice drinks, issues have been seen with syrups, kits and ready to drink pouches of slush ice drinks, and the FSA has extended its advice to include these.
The last assessment by the EFSA was a reevaluation in 2017. It found that there is no safety concern for the use of glycerol as a food additive for the general population, and thus no need for an acceptable daily intake (ADI) to be set.
