Food & Drink / Compounds / 3-MCPD (3-Monochloropropane-1,2-diol)

3-MCPD (3-Monochloropropane-1,2-diol) in food: ingestion safety

High risk

(People-specific data is limited; this page draws from human adult context.) 3-MCPD is a food processing contaminant with established renal and reproductive toxicity. EFSA TDI is 2 microg/kg bw/day.

What is 3-mcpd (3-monochloropropane-1,2-diol)?

3-MCPD (3-Monochloropropane-1,2-diol) is a food processing contaminant, chlorinated diol, process contaminant.

The IUPAC name is 3-chloropropane-1,2-diol.

Also known as: 3-MCPD, 3-Monochloropropane-1,2-diol, alpha-Chlorohydrin, 3-Chloro-1,2-propanediol.

IUPAC name
3-chloropropane-1,2-diol
CAS number
96-24-2
Molecular formula
C3H7ClO2
Molecular weight
110.54 g/mol
SMILES
OCC(O)CCl
PubChem CID
7290

Risk for people

High risk

3-MCPD is a food processing contaminant with established renal and reproductive toxicity. EFSA TDI is 2 microg/kg bw/day.

3-MCPD forms during hydrolysis of vegetable proteins (soy sauce, HVP production) and during refining of edible oils. IARC classifies it as Group 2B (possibly carcinogenic to humans). EFSA established a tolerable daily intake (TDI) of 2 microg/kg bw/day in 2018, based on nephrotoxicity in rats. Chronic exposure in animal studies causes kidney tubular hyperplasia and testicular toxicity. Dietary exposure is the primary route for adults.

Symptoms of exposure

  • Generally asymptomatic at dietary exposure levels
  • Renal effects at high doses (per animal studies)
  • Reproductive/testicular effects at high doses (per animal studies)
What to do: Minimize consumption of foods with known high 3-MCPD levels (refined oils, soy sauce, HVP). Choose cold-pressed or minimally refined oils where possible.

Regulatory consensus

4 regulatory and scientific bodies have classified 3-MCPD (3-Monochloropropane-1,2-diol). The classifications differ — that's the data.

AgencyYearClassificationNotes
IARC2012Group 2B (possibly carcinogenic to humans)Monograph 101. Based on sufficient evidence in animals, inadequate in humans.
EFSA2018TDI of 2 microg/kg bw/day establishedEFSA CONTAM Panel opinion on 3-MCPD and its fatty acid esters. Based on nephrotoxicity.
EU Commission2020Maximum levels in vegetable oils establishedRegulation (EU) 2020/1322 setting maximum levels for 3-MCPD and glycidyl fatty acid esters in vegetable oils and foods containing vegetable oils.
JECFA2016PMTDI of 4 microg/kg bw/day (2016, under review)Joint FAO/WHO Expert Committee on Food Additives evaluated 3-MCPD. PMTDI based on renal effects in rats.

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter 3-mcpd (3-monochloropropane-1,2-diol)

  • Food
    Major source; formed during acid hydrolysis of vegetable proteins. Levels can exceed 1 mg/kg.
  • Food
    Forms during oil refining (deodorization step). Regulated in EU.
  • Food
    Process contaminant from acid hydrolysis of plant proteins.
  • Food
    Low levels formed during baking/toasting processes.
  • Food
    Trace amounts from smoking process.
  • Food
    Trace levels from refined vegetable oil ingredients. EFSA flagged as concern for formula-fed infants.

Safer alternatives

Lower-risk approaches that achieve a similar outcome to 3-MCPD (3-Monochloropropane-1,2-diol):

  • Naturally brewed soy sauce (lower 3-MCPD than acid-hydrolyzed)
  • Cold-pressed or virgin oils (not subjected to refining/deodorization)

Frequently asked questions

Why do regulators disagree about 3-mcpd (3-monochloropropane-1,2-diol)?

3-MCPD (3-Monochloropropane-1,2-diol) has been classified by 4 agencies including IARC, EFSA, EU Commission, JECFA, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See 3-MCPD (3-Monochloropropane-1,2-diol) in the food app

Look up products containing 3-mcpd (3-monochloropropane-1,2-diol), compare to alternatives, and explore the full data record.

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Sources (4)
  1. — regulatory_body
  2. — regulatory_body
  3. — expert_curation
  4. — expert_curation

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →