What is E240?

Complete guide to understanding E240 (Formaldehyde) — a definitively carcinogenic preservative that has been banned from food use globally

The Quick Answer

E240 (Formaldehyde) was a chemical preservative used to prevent bacteria, mold, and yeast growth in foods.

However, formaldehyde has been banned from food use because it is definitively classified as a Group 1 Carcinogen — meaning there is sufficient evidence that it causes cancer in humans. It is also classified as a Mutagen and Reproductive Toxicant. The additive has been delisted from all major food regulatory systems globally.

Unlike some banned additives (E311, E312) that were removed due to insufficient data, E240 was removed because the hazard data is overwhelming and definitive: formaldehyde causes cancer.

What Exactly Is It?

E240 is formaldehyde, the simplest aldehyde compound — a colorless, pungent gas commonly dissolved in water (formalin solution: 34-38% formaldehyde).

Chemical formula: H₂CO or CH₂O — one of the smallest organic molecules.

Origin:

– Natural: Produced when protein-rich foods are smoked or heated; occurs naturally in small amounts in many foods
– Synthetic: Industrially produced by oxidation of methanol on large scales

Key properties:

– Highly effective antimicrobial agent; prevents bacteria, mold, yeast
– Pungent odor; colorless volatile gas
– Soluble in water and many organic solvents
– Highly irritating at high concentrations
– Causes skin, eye, respiratory irritation
– Can cause allergic sensitization
– CRITICAL: Group 1 Carcinogen; causes cancer in humans

Health Hazards: Why E240 Was Banned

Carcinogenicity: DEFINITIVE (Group 1)

IARC Classification (2015): Group 1 Carcinogen — “Sufficient evidence of carcinogenicity in humans”

What this means: There is sufficient evidence from epidemiological studies in humans that formaldehyde causes cancer. This is the highest hazard classification — stronger than “probable carcinogen” or “possible carcinogen.”

Primary cancer type:

– Nasopharyngeal cancer: Strong association; increased risk well-documented
– Sinonasal cancer: Strong association
– Myeloid leukemia: Sufficient evidence in animals; concern in humans

Evidence source: Occupational health studies of industrial workers with long-term formaldehyde exposure

Key research populations:

– Embalmers (occupational exposure)
– Pathologists and laboratory technicians
– Textile workers (using formaldehyde-treated fabrics)
– Plywood and particleboard manufacturing workers

Mutagenicity: DEFINITIVE (Category 1B)

Classification: Category 1B Mutagen — Presumed to cause genetic damage

What this means: Formaldehyde is presumed to cause mutations in DNA — permanent changes to genetic material that can be inherited.

Mechanism: Direct DNA binding; formation of DNA cross-links; chromosome aberrations in animal studies

Implication: Potential for inherited genetic damage; possible multi-generational health effects

Reproductive Toxicity: DEFINITIVE (Category 1B)

Classification: Category 1B Reproductive Toxicant — Presumed to impair fertility or harm fetus

What this means: Formaldehyde is presumed to damage reproduction or harm fetal development

Evidence: Animal studies showing developmental effects; concern for fetal exposure during pregnancy

Acute Toxicity: MODERATE-HIGH

– Irritant: Causes skin, eye, respiratory irritation at concentrations >0.1 ppm
– Sensitizer: Can cause allergic contact dermatitis
– GHS Classification: Acute toxicity Category 3-4 (harmful if swallowed)
– Occupational exposure symptoms: Coughing, wheezing, eye watering, nasal discomfort

Why No Safe Exposure Level Exists

Critical regulatory principle: Genotoxic carcinogens (substances that damage DNA) have no established “safe threshold.”

Cancer risk increases with exposure — there is no exposure level below which cancer risk is zero. Regulatory approach:

– ALARA principle: “As Low As Reasonably Achievable”
– Complete prohibition in food additives
– Minimize occupational exposure through engineering controls
– Cannot approve a genotoxic carcinogen as food additive under any circumstances

Historical Use (Before Ban)

E240 was used as a food preservative for:

– Fruit juices
– Wine
– Jams and pickles
– Baked goods
– Processed meats
– Fish and shellfish

How it worked: Antimicrobial preservation; prevented bacterial spoilage and mold/yeast growth

Typical use levels: 50-200 mg/kg depending on food type

Why approved historically: Approved before comprehensive health hazard data existed (pre-1970s); excellent antimicrobial effectiveness; long industrial history

When hazards became clear: 1970s-1980s occupational health research identified carcinogenic risk; 1995 IARC classified as probable carcinogen; 2015 upgraded to definitive Group 1 carcinogen

Current Regulatory Status

European Union

Status: DELISTED — not approved for food use

Direct addition: Prohibited for human food

Indirect residues: Trace formaldehyde may remain in some food additives manufactured using formaldehyde (alginates, carrageenan, hexamine) but at much lower levels than direct E240 addition

Regulatory basis: Group 1 Carcinogen classification; automatic disqualification from food additive approval

United States

Status: NOT approved as food additive

FDA position: Formaldehyde never approved for human food preservation

Limited uses: Only approved for animal feed and drinking water (with restrictions)

Regulatory authority: EPA and OSHA regulate formaldehyde as hazardous chemical substance

International (Codex Alimentarius)

Status: DELISTED before 2017 from international food additives list

Global pattern: All major regulatory systems (EU, US, Canada, Australia, New Zealand) prohibit direct use

Illegal Use

China: Well-documented illegal use in food (contaminated aquatic products, milk products)

Other developing countries: Occasional illegal use due to cost savings and weak enforcement

Health consequences: Occupational and consumer exposure to definitive carcinogen through contaminated food

Natural Formaldehyde in Foods

Important distinction: Formaldehyde naturally occurs in small amounts in food due to cooking and metabolism — this is different from deliberate E240 addition.

Natural sources:

– Protein-rich foods when heated/smoked: Meat, fish
– Fruits and vegetables: Small amounts naturally
– Body metabolism: Endogenous production ~50 mg/day in humans

Regulatory tolerance:

– Small amounts of formaldehyde are unavoidable in food
– Regulatory focus: Minimize ADDED formaldehyde
– Direct addition as E240: Completely unacceptable
– Trace amounts from other sources: Tolerated as unavoidable

Formaldehyde in Other Food Additives (Indirect Use)

Formaldehyde is still used in manufacturing some approved food additives:

Key point: Regulatory justification for allowing these additives despite formaldehyde connection: residual levels are significantly lower than direct E240 addition would have been, and they serve important food safety functions.

The Bottom Line

E240 (Formaldehyde) is a banned chemical preservative that was removed from food use because it definitively causes cancer in humans.

What you should know:

• It’s banned globally: Not approved in EU, US, or internationally for human food
• It causes cancer: Group 1 Carcinogen with sufficient evidence from human epidemiological studies
• It’s a mutagen: Can cause permanent genetic damage (Category 1B Mutagen)
• It’s a reproductive toxicant: Can impair fertility and harm fetal development
• No safe level exists: As a genotoxic carcinogen, no safe exposure threshold can be established
• Regulatory basis is definitive: Unlike some banned additives (E311, E312) removed for insufficient data, E240 was removed because hazard data overwhelmingly prove danger
• It’s still illegally used: Some manufacturers in developing countries illegally add formaldehyde to reduce costs and extend shelf life
• Indirect exposure minimal: Some approved additives (alginates, carrageenan) are manufactured using formaldehyde, but residual levels are much lower than direct E240 use