E231 · Orthophenylphenol
- WHO
- Safe
- FDA
- Safe
- EFSA
- Safe
- FSANZ
- Safe
- Japan
- Safe
- UK FSA
- Safe
- Health Canada
- Safe
What is E231?
Orthophenylphenol (OPP), also called 2-phenylphenol, is a fungicide applied to the surface of citrus fruits to prevent mold during storage and transport. It is approved for this post-harvest use in the US and EU within set residue limits, though it is not added to the edible flesh of food. It is also used more broadly as a surface disinfectant outside the food industry. Because residues concentrate in the peel, washing or peeling treated citrus reduces exposure; it is classified by some agencies as a possible human carcinogen at very high, long-term exposure levels seen in animal studies, though typical dietary exposure is well below levels of concern.
Also appears on labels as: Orthophenylphenol, o-Phenylphenol, 2-Phenylphenol, Food grade orthophenylphenol, Additivo alimentare orthophenylphenol, Additif alimentaire orthophenylphenol, Lebensmittelzusatzstoff orthophenylphenol, Orthophenylphenol powder, Orthophenylphenol solution, OPP, 2-Phenyl-1-phenol, E231.
What the evidence says
- Peel residues can be relatively high; washing or peeling citrus before use (e.g., zesting) reduces exposure.
- Classified by IARC as possibly carcinogenic to humans (Group 2B) based on high-dose animal studies; real-world food exposure is regulated to stay well below levels linked to effects.
- Can cause skin or respiratory irritation with direct, concentrated, non-food exposure (e.g., industrial handling).
Frequently asked questions
Is E231 safe?
Our overall verdict for E231 (Orthophenylphenol) is “Safe”, based on the most cautious of the major regulators’ positions — FDA: safe; WHO: safe; EFSA: safe; FSANZ: safe; Japan: safe; UK FSA: safe; Health Canada: safe.
Is E231 vegan, halal or gluten-free?
According to our ingredient data for Orthophenylphenol — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.
What is E231 and why is it used?
Orthophenylphenol (OPP), also called 2-phenylphenol, is a fungicide applied to the surface of citrus fruits to prevent mold during storage and transport. It is approved for this post-harvest use in the US and EU within set residue limits, though it is not added to the edible flesh of food. It is also used more broadly as a surface disinfectant outside the food industry. Because residues concentrate in the peel, washing or peeling treated citrus reduces exposure; it is classified by some agencies as a possible human carcinogen at very high, long-term exposure levels seen in animal studies, though typical dietary exposure is well below levels of concern.
Does E231 contain allergens?
No known allergens are recorded for Orthophenylphenol.
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This page summarises publicly available regulatory assessments and research. It is general information, not medical advice. Sources: EFSA, FDA, WHO and the studies linked above.