What is E310?
Complete guide to understanding E310 (Propyl Gallate) — a synthetic antioxidant with tightening regulations and data gap concerns
The Quick Answer
E310 (Propyl Gallate) is a synthetic antioxidant used to prevent fats and oils in processed foods from becoming rancid, extending shelf life.
It’s been used since 1948 and is approved globally, but it’s one of the more “actively monitored” antioxidants due to gaps in the scientific database. EFSA lowered the safety limit (ADI) in 2014, and the EU tightened manufacturing restrictions and impurity limits in 2024 — reflecting precautionary regulatory approaches to address data gaps.
It’s considered safe at current use levels, but it’s a good candidate for reduction or replacement if you prefer to avoid synthetic additives with incomplete toxicological datasets.
📌 Quick Facts
- Chemical Name: Propyl Gallate (propyl 3,4,5-trihydroxybenzoate)
- Type: Synthetic antioxidant; gallate ester; prevents fat/oil rancidity
- Found in: Oils, fats, processed meats, snacks, baked goods, soups, cereals, spices
- Safety Status: Approved; deemed safe at current food use levels (EFSA 2014)
- Approved by: EFSA, FDA, JECFA, Australia, New Zealand, Canada, Japan, most countries
- ADI (EFSA): 0.5 mg/kg body weight/day (lowered from 1.4 mg/kg in 2014)
- ADI (JECFA): 0-1.4 mg/kg body weight/day (unchanged since 1996)
- Regulatory trend: Tightening; impurity limits reduced (2024); manufacturing restricted
- Main concern: Incomplete carcinogenicity and reproductive toxicity data; impurities
What Exactly Is It?
E310 is propyl gallate, a white crystalline powder — 100% synthetic, created by combining gallic acid with propanol.
Chemical formula: C₁₀H₁₀O₅ — an ester compound that doesn’t occur in nature.
Key properties:
– Highly effective antioxidant in lipid (fat) systems
– Does NOT occur naturally; 100% synthetic
– Odorless powder with slightly bitter taste
– Darkens in presence of iron salts
– Can cause skin irritation (occupational hazard)
– Often used in combination with other antioxidants
– Cannot be combined with nitrites/nitrates (chemical incompatibility)
– Approved since 1948; relatively old antioxidant by modern standards
Where You’ll Find It
E310 is found in many processed foods containing fats and oils:
| Category | Specific Examples | Function |
|---|---|---|
| Fats & Oils | Vegetable oils, animal fats, cooking oils | Prevents oxidation and rancidity |
| Processed Meats | Sausages, bacon, processed meat products | Prevents fat oxidation; extends shelf life |
| Snacks | Chips, crackers, pastries, oily snacks | Maintains flavor and freshness |
| Baked Goods | Cakes, pastries, instant mixes | Prevents fat oxidation in dry products |
| Soups & Broths | Instant soups, powdered broths, dehydrated potatoes | Preserves fat components |
| Sauces | Various sauces with oil/fat content | Antioxidant preservation |
| Cereals | Breakfast cereals with oil | Prevents rancidity |
| Spices | Dried spice preparations | Protects oil content |
| Dairy | Powdered milk for vending machines | Fat preservation |
Permitted levels vary by product: Typically 0.01-0.02% in most foods; up to 0.02% in margarine; up to 0.006% in processed meats (combined with other antioxidants).
Why Is E310 Used?
E310’s primary function: prevent fats and oils from becoming rancid.
Why food companies choose it:
– Highly effective in lipids: Works very well in fat-containing systems
– Long history: Used since 1948; well-established in industry
– Cost-effective: Relatively inexpensive compared to alternatives
– Minimal flavor impact: Doesn’t noticeably change taste
– Synergistic combinations: Works well with BHA, BHT, TBHQ
– Multiple applications: Suitable for many food categories
– Proven function: Decades of industrial use demonstrates effectiveness
Why not use natural alternatives?
– Natural antioxidants (vitamin E, rosemary extract) less effective in lipids
– Significantly more expensive
– Less stable; shorter shelf life
– Less compatible with various food systems
Is It Safe? The Complicated Answer
The Official Position (Safe at Current Levels)
E310 is approved and deemed safe at current food use levels by major regulators.
| Authority | Position | ADI | Status |
|---|---|---|---|
| EFSA (2014) | Approved; “not of safety concern” at current use | 0.5 mg/kg bw/day | Approved; monitored |
| JECFA (1996) | Approved | 0-1.4 mg/kg bw/day | Unchanged since 1996 |
| FDA (US) | Approved | Not numerically specified | Limited uses (oils, meats) |
| EU (2024) | Approved with tighter restrictions | 0.5 mg/kg (same as EFSA) | Impurity limits reduced; manufacturing restricted |
Critical Finding: Data Gaps
What EFSA found:
– Insufficient carcinogenicity data: Limited long-term animal studies; 1993 study found “little or no effect” but database overall remains limited
– Reproductive toxicity gaps: Limited data on developmental effects; uncertainties remain
– Basis for current ADI: Derived from 90-day rat study (NOAEL 135 mg/kg bw/day) with conservative 300x safety factor
– Concern about exposure: Some exposure scenarios (high consumers) exceeded ADI, but EFSA deemed this acceptable given conservative exposure assumptions
Safety Assessment
| Safety Criterion | Finding | Assessment |
|---|---|---|
| Acute Toxicity | Very low at food use levels | Safe |
| Chronic Toxicity | No adverse effects at 135 mg/kg bw/day (90-day rat study) | Safe at current food levels |
| Carcinogenicity | 1993 study: “little or no effect”; database limited | Not definitively established as carcinogenic; more data needed |
| Reproductive/Developmental | Limited data; uncertainties | Not established as concern; but insufficient data |
| Genotoxicity | Negative in available tests | Not genotoxic |
| Estrogen Effects | 2009 study: acts as estrogen antagonist; mechanism unclear | Noted but significance unclear; not deemed safety concern |
| Overall Assessment | EFSA: “not of safety concern” at current uses and levels | Approved but actively monitored; precautionary measures increasing |
Why Regulators Tightened Controls (2024)
EU actions in 2024 demonstrate growing precautionary approach:
– Manufacturing restrictions: Limited use of certain catalysts (precautionary)
– Impurity limits reduced: Arsenic & mercury to 0.1 mg/kg (from higher); lead to 0.3 mg/kg
– Reasoning: Data gaps on potential toxins; precautionary reduction of exposure
– Pattern: Not due to new safety data, but to address uncertainty through restriction
ADI Comparison
EFSA lowered the ADI in 2014 due to different interpretation of safety data:
– SCF/EC (1976): 0-0.2 mg/kg (very restrictive)
– JECFA (1996): 0-1.4 mg/kg (more permissive)
– EFSA (2014): 0.5 mg/kg (middle ground; based on NOAEL 135 mg/kg with 300x safety factor)
For 70 kg adult: EFSA’s ADI of 0.5 mg/kg = ~35 mg/day maximum allowed; typical food use levels result in much lower actual exposure.
Health Concerns (Potential but Not Established)
Concerns that have been raised but not definitively linked to food use:
– Carcinogenicity: 1993 study found “little or no effect”; limited long-term data remains
– Estrogen antagonism: 2009 study found hormonal effects; health implications unclear
– Enzyme inhibition: Observed in studies; relevance to food levels unclear
– Allergic reactions: Possible in sensitive individuals (not documented as widespread)
– Heavy metal content: Impurities concern (EU addressed in 2024)
– Reproductive toxicity: Limited data; not established as concern but uncertainties remain
The Bottom Line
E310 (Propyl Gallate) is an approved synthetic antioxidant deemed safe at current food use levels, but with notable data gaps and tightening regulations.
What you should know:
- It’s approved but monitored: EFSA deemed it safe but acknowledged significant data gaps
- It’s purely synthetic: 100% chemically engineered; doesn’t occur in nature
- Regulations are tightening: ADI lowered (2014); manufacturing restricted (2024); impurity limits reduced (2024)
- Data gaps exist: Carcinogenicity and reproductive toxicity databases incomplete
- It’s been used since 1948: Long industrial history; but not extensively modern-tested
- No proven health crisis: Despite decades of use, no documented public health emergency
- Precautionary approach: EU regulations reflect “reduce exposure where uncertain” philosophy
- Better alternatives available: Vitamin E (E307) is far less controversial if available