What is E1502?
Complete guide to understanding butane-1,3-diol in your food
The Quick Answer
E1502 is butane-1,3-diol (also called 1,3-butylene glycol), a synthetic alcohol used as a solvent for food flavorings and humectant.
It’s used to dissolve and carry flavor compounds, particularly in foods with grape, fruit, and other natural flavorings.
It’s a colorless, water-soluble liquid with a slightly sweet taste that appears in foods and cosmetics.
📌 Quick Facts
- Category: Flavor solvent, humectant, carrier
- Found in: Flavoring agents, tobacco products, cosmetics, pharmaceuticals, food additives
- Safety Status: GRAS (Generally Recognized As Safe) by FDA
- Approval Status: Unapproved as E-number in EU (not officially authorized)
- Chemical Formula: CH₃CH(OH)CH₂CH₂OH
- Natural Occurrence: Found in small amounts in bell peppers and other vegetables
- Alternative Names: 1,3-Butylene glycol, 1,3-butanediol
What Exactly Is It?
E1502 is a synthetic alcohol made from chemical synthesis, though it can also be produced through fermentation.
The name comes from its chemical structure: a 4-carbon chain (butane) with two hydroxyl groups (alcohol functional groups) in positions 1 and 3.
In technical terms, it’s a diol—meaning it has two alcohol groups attached to its carbon backbone.
E1502 appears as a clear, colorless liquid with a slightly sweet, bittersweet taste, and is completely miscible (mixes) with water.
Important distinction: E1502 (butane-1,3-diol) should not be confused with 1,4-butanediol (a different isomer used in industrial applications, which is toxic in food).
Where You’ll Find It
E1502 appears primarily in:
• Flavor extracts and flavoring solvents
• Tobacco products and smokeless tobacco
• Cosmetics and personal care products
• Pharmaceutical formulations
• Selected beverages and flavored products
• Resins and industrial applications
E1502 is used mainly as a flavoring solvent—not a direct additive in the finished food itself.
Most commonly, it appears in the supply chain before reaching consumers: in concentrated flavor extracts used by food manufacturers, not typically in the final product.
Why Do Food Companies Use It?
E1502 serves one primary function: dissolve and stabilize flavor compounds.
In flavor extraction: Natural flavor compounds (particularly from grape, fruit, and botanical sources) are often lipophilic (fat-soluble or organic-soluble). E1502 dissolves these compounds effectively, allowing them to be mixed into water-based or emulsified food systems.
As a humectant: E1502 attracts and binds moisture, helping flavored products maintain consistency and preventing them from drying out.
In tobacco: Its primary documented use is in tobacco products, where it serves as a humectant and flavor carrier.
Why use it instead of alternatives: E1502 is water-soluble (unlike simple oils), stable across temperature ranges, and has minimal taste when used in appropriate amounts.
Without E1502, many concentrated flavor extracts would be difficult to formulate and distribute to food manufacturers.
Is It Safe?
E1502 is recognized as safe by the FDA but has a complex regulatory status.
The FDA has granted E1502 GRAS (Generally Recognized As Safe) status for use as a flavor solvent, and WHO/JECFA has evaluated it as acceptable.
Important regulatory note: E1502 is not officially approved as an E-number in the European Union—making it technically an “unapproved E-number.” This does not mean it’s unsafe, but rather that formal EU authorization is pending or has not been completed.
Safety profile:
• Long-term studies in rats and dogs at 1-10% dietary levels for 2 years showed no adverse effects.
• It is rapidly metabolized into hydroxybutyrate and acetoacetate (natural metabolic compounds).
• It does not accumulate in body tissues.
• It occurs naturally in small quantities in bell peppers and other vegetables.
Natural vs Synthetic Version
E1502 is primarily synthetic—chemically manufactured in laboratories.
However, it can be produced through fermentation of sugars and molasses using specific bacteria strains, making bio-based production possible.
Most commercial E1502 is synthetically produced for cost and consistency reasons.
The synthetic and fermented versions are chemically identical—your body cannot distinguish between them.
Naturally occurring E1502 is found in very small amounts in vegetables like bell peppers.
Natural Alternatives
Want to avoid E1502?
In flavor formulations, companies sometimes use:
• Propylene glycol (E1520): Similar properties, more commonly approved in EU
• Glycerin: Natural humectant, but less effective for some flavor solvency
• Water-based extracts: Less concentrated, require higher volumes
• Ethanol: Traditional solvent, but more volatile
• Gum arabic or acacia gum: Natural carrier but different properties
Many alternatives have limitations: lower solvency for certain flavors, higher cost, or regulatory restrictions.
So E1502 remains popular in industries where it’s permitted, particularly in tobacco and cosmetics.
The Bottom Line
E1502 is a synthetic alcohol used primarily as a solvent for flavor extracts and humectant.
It’s not commonly found in finished consumer foods—mainly in the flavor industry supply chain and in cosmetic/pharmaceutical products.
The FDA recognizes it as GRAS (safe), though the EU has not formally authorized it as an E-number.
Long-term safety studies in animals show no adverse effects, and it’s rapidly metabolized without accumulation in the body.
However, it should not be confused with the toxic industrial chemical 1,4-butanediol.
If you have concerns about E1502 exposure, check cosmetic and food additive labels, though your actual dietary exposure is likely minimal since it’s primarily used as a processing solvent rather than a direct food additive.