What is it?
Propylene glycol is a clear, odourless, slightly syrupy liquid made from petroleum-based chemicals. It mixes with water and with most other liquids. The body breaks it down along the same route as lactic acid.
E-numbers / Other additives / E1520
Propylene glycol
also: Propane-1,2-diol · 1,2-Propanediol
A solvent and moisture-retaining additive used to carry flavours, colours and nutrients into food and drink.
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Glycerol, Water, Colours: Cochineal, Curcumin; Propylene Glycol, Emulsifier: Polysorbate 80, Acidity Regulators: Citric Acid, Potassium hydroxide.
E1520
Propylene glycol
Propylene glycol is a clear, odourless, slightly syrupy liquid made from petroleum-based chemicals.
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What propylene glycol is, what it does and where you will see it
What does it do?
It dissolves flavourings, colours and other additives so they spread evenly through a food or drink. It also holds on to moisture so food does not dry out, and it carries added vitamins or enzymes evenly through a product.
Where you will see it
Flavoured drinks and cordials, ready-made cakes and icing, flavoured crisps and snacks, salad dressings, some sweet coatings, and products with added colours or antioxidants. Labels call it propylene glycol, propane-1,2-diol or E1520.
What the science says
The body turns it into lactic acid and clears it
Once swallowed, propylene glycol is absorbed and turned mainly into lactic acid and pyruvate, which the body already makes when it uses energy. At the amounts in food it is cleared quickly and fully. Studies in animals and people found no build-up at normal intakes.
Reviewers estimated the highest intake in children at up to 23.3mg per kg of body weight a day, below the daily limit of 25mg.
2020Regulator reviewEFSA Panel on Food Additives and Nutrient Sources (ANS), re-evaluation of propane-1,2-diol (E 1520) as a food additive, EFSA Journal
Reviewers found no DNA damage
The lab and animal studies European reviewers looked at showed no sign that propylene glycol damages DNA or causes cancer. Their 2020 review raised nothing on DNA damage. The WHO's cancer agency has not classified it.
Reviewers found no sign of DNA damage in the available data.
2020Regulator reviewEFSA ANS Panel, re-evaluation of propane-1,2-diol (E 1520), EFSA Journal
No effects on fertility or unborn young in animal studies
The animal studies in the 2020 review showed no harm to fertility or development at the amounts eaten in food. Reviewers saw no reason to restrict it on those grounds.
Reproduction and development studies showed no harm, and estimated intakes stayed under the daily limit in every age group.
2020Regulator reviewEFSA ANS Panel, re-evaluation of propane-1,2-diol (E 1520), EFSA Journal
Reviewers asked for tighter limits on impurities
The 2020 review recommended tighter limits on lead and on traces left from making it, including propylene oxide, other glycols and propylene carbonate. These are impurities, not effects of propylene glycol itself, but the purity rules set when it was first approved had not kept up with modern testing.
Reviewers recommended lowering the lead limit below 2mg per kg and adding limits for propylene oxide and other glycol impurities.
2020Regulator reviewEFSA ANS Panel, re-evaluation of propane-1,2-diol (E 1520), EFSA Journal
Food is not the only place people get it
Propylene glycol is also used in medicines, cosmetics and some food packaging. Reviewers said looking at food additives alone may underestimate how much people take in overall, and asked for all sources to be added up. That is a gap in the data, not a finding of harm.
Reviewers recommended adding up propylene glycol from food additives and from other approved sources, since food alone may underestimate the total.
2020Regulator reviewEFSA ANS Panel, re-evaluation of propane-1,2-diol (E 1520), EFSA Journal
Where it stands with the regulators
Approved in the UK and the EU
Daily limit. 25mg per kg of body weight a day, about 1,750mg for a 70kg adult (international committee and European reviewers).
- Legal basis
- On the Food Standards Agency's approved list for England, Scotland and Wales
- Permitted foods
- As a carrier for colours, emulsifiers and antioxidants, up to 1,000mg per kg of the final food · As a carrier for enzymes, flavourings and nutrients, up to 3,000mg per kg from all sources · Drinks other than cream liqueurs, up to 1,000mg per litre from all sources
- Maximum levels
- 1,000mg per kg in the final food as a carrier for additives and in drinks, and 3,000mg per kg from all sources as a carrier for enzymes, flavourings and nutrients.
- History
- Propylene glycol has been an approved additive in the EU and UK for decades. European reviewers completed a full review in 2020 and saw no reason to change the daily limit of 25mg per kg. They recommended tighter purity rules on lead, propylene oxide and glycol impurities, and asked for intake from non-food sources to be counted too. No bans or new restrictions have followed.
Who should be careful
It is not one of the allergens UK law makes labels declare. People on certain medicines, particularly metronidazole or disulfiram, may clear propylene glycol more slowly, which is a concern with medicines rather than with the amounts in food. Babies clear it more slowly than adults, which is why some baby foods restrict it. Look for propylene glycol, propane-1,2-diol or E1520 if you want to avoid it. It is a carrier that nobody eats for its own sake, and the products it turns up in are mostly ultra-processed. Our UPF checker names those markers on a scanned pack.
The honest read
Propylene glycol is one of the most reviewed solvents in the additive rules. The 2020 European review looked at DNA damage, effects on fertility and development, and intake at every age, and saw no reason to change the daily limit. The open questions are technical: tightening the limits on impurities from manufacturing, and counting non-food sources in total intake. The body breaks it down along a route it uses for everyday sugars, and even children, who take in the most, stay under the daily limit at normal food intakes.
Common questions about propylene glycol
Is E1520 banned in the UK?
No. E1520 is an approved additive in the UK and is on the Food Standards Agency's list. The 2020 European review found no reason to remove or restrict it.
Is propylene glycol the same as antifreeze?
Propylene glycol is used in some antifreeze sold as less toxic than the ethylene glycol kind. Food-grade propylene glycol is the same chemical but must meet strict purity rules. The two are not interchangeable, and in food it is used in much smaller amounts to dissolve flavourings or hold moisture, not to stop anything freezing.
What foods contain E1520?
Mostly as a carrier for flavourings, colours and antioxidants in flavoured drinks and cordials, cakes, salad dressings, sweet coatings and flavoured snacks. Labels call it propylene glycol, propane-1,2-diol or E1520.
Is E1520 vegan?
Yes. It is made in a factory from petroleum-based chemicals and contains nothing from animals.
Sources
- EFSA ANS Panel: Re-evaluation of propane-1,2-diol (E 1520) as a food additive (PMC full text)
- UK FSA regulated products: E-1520 Propane-1,2-diol (propylene glycol)
- Approved additives and E numbers | Food Standards Agency
- Tiered intake assessment for propylene glycol in beverages, Food Additives and Contaminants Part A, 2025
Last reviewed: 20 June 2026
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