Is E1520 Propylene Glycol Safe to Eat? What This Additive Really Is

Few additives sound more alarming than E1520, propylene glycol, partly because the name is often linked to antifreeze. The reality is more reassuring: food-grade propylene glycol is a well-studied, approved ingredient used to keep foods moist and to carry flavours. Here is what it actually is and what the science says. For more, browse our food additives guides.

What is E1520 propylene glycol?

Propylene glycol is a clear, colourless, slightly sweet liquid that mixes readily with water. As the food additive E1520 it serves mainly as a humectant (a substance that holds moisture) and a carrier solvent for flavourings and colours. It is a completely different substance from ethylene glycol, the toxic compound used in some antifreeze; the two are often confused because of similar names, but they behave very differently in the body.

In fact, propylene glycol is so well tolerated that it is also used as a solvent in many liquid medicines, including children's syrups, and in cosmetics and personal-care products.

What does it do in food?

As a humectant and carrier, E1520 is used to:

• Keep cakes, icings, and baked goods soft and moist.
• Dissolve and carry flavourings, colours, and extracts so they disperse evenly.
• Stop dried or processed foods from drying out.
• Act as a solvent in flavour preparations and some food coatings.

Is propylene glycol safe to eat?

Yes, at the levels used in food. E1520 is approved in the European Union, the United Kingdom, and the United States, where the FDA classifies food-grade propylene glycol as Generally Recognised As Safe. The European Food Safety Authority has set an Acceptable Daily Intake, and the body readily metabolises propylene glycol into lactic acid, a normal substance produced by your own muscles during exercise.

What about the limits and cautions?

Because propylene glycol is consumed both in food and in medicines, regulators do place limits on its use to keep total intake comfortably within the safe range. Very high doses, far beyond anything achievable through normal food, could in theory burden the body, which is why amounts in food are capped. EU rules permit it in a relatively narrow set of applications, mainly as a carrier, so you will not find it in as many products as you might in the US.

For the vast majority of people eating normal diets, propylene glycol in food poses no health risk. The antifreeze association is a myth based on confusion with a different chemical.

Foods that commonly contain E1520

You are most likely to find propylene glycol in flavourings and colour preparations, where it acts as the carrier solvent, and in some cake icings, frostings, baked goods, and processed foods that need to stay moist. Its use is more widespread in the United States than in the EU and UK, where its permitted applications are more restricted.

The bottom line

E1520 propylene glycol is a moisture-retaining humectant and flavour carrier, completely distinct from toxic antifreeze chemicals, and is metabolised into harmless lactic acid. It is judged safe at food-use levels by EFSA and the FDA, and is even used in children's medicines. Within the limits regulators set, there is no reason for the average person to worry about it.