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AMMONIUM IODIDE

CAS 12027-06-4
45

Safety score · 0–100

Moderate

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

About

An inorganic iodide salt (NH₄I) used as an antimicrobial agent in cosmetics. While iodine is essential for skin health, ammonium iodide can be irritating to skin and eyes, and its oxidation can release free iodine which may cause allergic reactions.

Ammonium iodide (NH₄I, CAS 12027-06-4) is a white crystalline salt that dissociates in water to ammonium (NH₄⁺) and iodide (I⁻) ions. The iodide ion can be oxidized to elemental iodine (I₂) by air oxidation, especially in presence of acidic conditions or oxidizing agents. Elemental iodine is a broad-spectrum antimicrobial but is also a well-known skin sensitizer and irritant. Ammonium iodide's antimicrobial efficacy is attributed to this slow release of iodine. Skin irritation results from both the salt's hygroscopic nature (drawing water from skin) and the oxidizing iodine. It is used less frequently in modern cosmetics due to these drawbacks and the availability of milder alternatives.

Function

ANTIMICROBIAL

Skin benefits

  • Broad-spectrum antimicrobial activity
  • Iodine supports thyroid function when absorbed (not relevant topically)
  • Antifungal properties useful in scalp care

Known concerns

  • Skin and eye irritant — releases iodine on oxidation
  • Known skin sensitizer/allergen in many individuals
  • Hygroscopic salt may disrupt skin barrier function
  • Air oxidation creates variable potency and potential brown discoloration
  • Iodine allergy individuals must avoid

References

EU

EU CosIng database

European Commission cosmetic ingredient registry — regulatory status, restrictions, authorised functions.

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This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve — always read the physical product label and consult a healthcare professional for personal concerns.