Is Humectant 422 Safe to Eat? Understanding Glycerol's Role in Food

December 7, 2025 •

3 min read

According to numerous food safety authorities, including the FDA and EFSA, humectant 422, also known as glycerol, is generally recognized as safe for consumption. This common food additive is found in many products, from baked goods to slush ice drinks, and plays a vital role in food preservation and texture.

Quick Summary

This article explains what glycerol (humectant 422) is, its widespread use in the food industry, and why regulatory bodies consider it safe. It also covers potential side effects, particularly with excessive consumption, and provides consumer advice, especially concerning children's intake of high-glycerol products like slushies.

Key Points

Generally Recognized as Safe (GRAS): Humectant 422, or glycerol, is deemed safe for human consumption by major food safety authorities like the FDA and EFSA, particularly within normal dietary amounts.
Multi-purpose Additive: It functions as a humectant (moisture-retainer), sweetener, solvent, and texturizer, enhancing the shelf life and quality of many food items.
Moderation is Key: Excessive consumption of glycerol can lead to mild side effects such as headaches, bloating, and diarrhea, as it draws water into the intestines.
Special Consideration for Children: High intake from products like slush ice drinks can cause glycerol intoxication in young children, prompting consumer warnings and industry guidance.
Natural and Synthetic Sources: Glycerol is a natural component of fats but is also commercially produced from vegetable oils or through fermentation, with stringent quality controls in place.

What is Humectant 422 (Glycerol)?

Humectant 422, more commonly known as glycerol or glycerin, is a colorless, odorless, and viscous liquid with a sweet taste. Chemically, it is a sugar alcohol that naturally occurs in all animal and vegetable fats. In commercial food production, it is typically derived from plant oils, like palm or soy, or as a byproduct of biodiesel production. Its primary function as a humectant is to attract and retain moisture, which helps keep foods from drying out and extends their shelf life.

The Diverse Roles of Glycerol in the Food Industry

Glycerol's versatility makes it a staple ingredient in a wide variety of food products beyond simply retaining moisture. It acts as a solvent for flavors and colors, a sweetener, a preservative, and a texture enhancer. For example, in confectionery, it helps prevent sugar crystallization, while in low-fat cookies, it can serve as a filler. It is also found in beverages, such as flavored drinks and some extracts.

Safety Approval from Global Authorities

Multiple international food safety organizations have evaluated and approved the use of glycerol in food production, confirming that humectant 422 is safe to eat within normal consumption levels.

U.S. Food and Drug Administration (FDA): The FDA classifies glycerol as "Generally Recognized as Safe" (GRAS). This designation is based on expert consensus that the substance is safe under its intended conditions of use.
European Food Safety Authority (EFSA): After a re-evaluation in 2017, the EFSA concluded there was no safety concern regarding glycerol (E 422) as a food additive at current exposure levels. The EFSA did note that certain manufacturing processes should be monitored to ensure purity, and more data was requested on acute exposure scenarios.
Joint FAO/WHO Expert Committee on Food Additives (JECFA): This joint committee has also endorsed glycerol, assigning it an acceptable daily intake (ADI) of "not specified," indicating its low toxicity.

Potential Side Effects and Overconsumption Risks

While considered safe in typical food amounts, excessive consumption of glycerol can lead to adverse effects, primarily related to gastrointestinal issues. This is because glycerol draws water into the intestines, which can have a laxative effect.

Gastrointestinal discomfort: High intake can cause headaches, dizziness, bloating, nausea, and diarrhea.
Glycerol Intoxication: In rare cases, primarily linked to young children consuming large amounts of high-glycerol products like slush ice drinks in a short time, intoxication has occurred. Symptoms include headaches, sickness, and low blood sugar (hypoglycemia). This has prompted updated guidance from food safety bodies in the UK to protect vulnerable consumers.

Consumer Advice Regarding Humectant 422

To consume glycerol safely, moderation is key, especially for children. Food safety agencies have issued specific recommendations to industry and consumers regarding high-glycerol products. The Food Standards Scotland, for example, advises against offering high-glycerol slushies to children under seven and recommends labeling. For the general population, the amount of glycerol in typical food products is not enough to cause concern.

Humectant 422 (Glycerol) vs. Other Additives


Feature	Humectant 422 (Glycerol)	Other Sugar Alcohols (e.g., Sorbitol, Mannitol)	Diethylene Glycol (DEG)
Classification	Sugar alcohol / Polyol	Sugar alcohol / Polyol	Toxic chemical
Food Use	Safe, widely used food additive	Used as sweeteners, fillers; some require laxative warning	Not for food use; potentially fatal if ingested
Natural Occurrence	Natural component of fats; also fermented	Found naturally in some fruits and plants	Not naturally occurring in safe food
Toxicity	Very low toxicity; excessive intake can cause mild GI issues	Very low toxicity; excessive intake can cause diarrhea	Highly toxic and dangerous
Historical Incidents	Used in place of DEG in past contamination cases	None noted related to widespread poisoning	Responsible for multiple fatal poisonings globally when fraudulently substituted for glycerol

Conclusion

For the average consumer, humectant 422 is a safe and widely used food additive. It is approved by leading food safety bodies worldwide and has a long history of safe use in food and pharmaceutical products. The key to safe consumption, as with many food components, lies in moderation. While the general population has nothing to fear from the glycerol levels found in everyday food, parents of young children should be mindful of excessive intake from products like slushies, which contain higher concentrations, and follow guidance from national food standards agencies. Ultimately, understanding glycerol's role helps distinguish it from more concerning chemical contaminants and supports informed dietary choices.

An excellent resource for learning more about food additives is the International Food Information Council (IFIC) at their website.

Frequently Asked Questions

Humectant 422, or glycerol, can be derived from either natural or synthetic sources. It is often a byproduct of soap and biodiesel manufacturing from animal fats or vegetable oils, but can also be produced through the fermentation of sugars.

While allergic reactions to glycerol are rare, some individuals have reported skin reactions like urticaria, or hives, upon contact. For those with allergies to its source materials (e.g., soy), alternative sources or consultation may be necessary.

Glycerol is used in a wide range of products to maintain moisture and texture. Common foods include marshmallows, icings, soft candies, baked goods, energy bars, and various beverages and extracts.

In slush ice drinks, glycerol is used to maintain the 'slush' consistency by preventing the liquid from freezing solid. It also acts as a sweetener and, in some cases, a sugar replacement.

No, E422 is simply the European Union's designated E-number for glycerol, which is the chemical compound known as humectant 422. They refer to the same substance.

Glycerol is generally safe in the small amounts found in most foods. However, excessive amounts, such as those found in high-glycerol slushies, can cause intoxication in young children due to their lower body weight. Food safety agencies advise against giving these drinks to children under a certain age.

While not considered highly toxic, very high or rapid consumption of glycerol can lead to adverse effects like severe dehydration, cardiac arrhythmias, or hyperosmolar nonketotic coma, though these are extremely rare in a dietary context and more relevant to massive oral or parenteral doses.