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Moumoujus

OXYQUINOLINE SULFATE.

Avoid CAS 134-31-6 / ANTIMICROBIAL, CHELATING

Oxyquinoline Sulfate is a synthetic chelating agent recognized for its broad-spectrum antimicrobial properties, inhibiting the growth of bacteria and fungi. Primarily employed as a stabilizer and preservative, its utility in skincare is overshadowed by significant safety concerns regarding leave-on applications.

Summary

antimicrobial chelator emulsion stabilising bacteriostatic fungistatic preservative

Science

Mechanism of Action

This compound acts as a chelator by binding trace metals within a formulation, a mechanism crucial for stabilizing hydrogen peroxide in hair care products. Furthermore, its antimicrobial activity stems from chelating essential metals required for microorganism metabolism, thereby functioning as a bacteriostatic and fungistatic agent.

Research

Clinical Evidence

Low confidence
Effective range N/A
Optimal

N/A

Key findings

  1. 01 Epidermal patch tests utilizing an aqueous solution of Oxyquinoline Sulfate at concentrations exceeding 0.01% resulted in positive skin reactions, manifesting as inflammation and clear signs of infiltration.
  2. 02 Oxyquinoline (the non-sulfate form), when tested at 1% in petrolatum, demonstrated no irritant or sensitizing properties. However, this finding is specific to the non-sulfate form and a different base.

Transparency

Dusting Analysis

Not commonly dusted

Oxyquinoline Sulfate serves primarily as a chelator, stabilizer, and antimicrobial preservative. It is not typically employed as a precision active ingredient in a manner where 'dusting' or high-concentration topical application for direct skin benefits would be relevant or recommended.

The Formula

Formulation

Solubility
Water
Optimal pH N/A
0 7 14

Stability

This ingredient exhibits sensitivity to light and necessitates storage in light-resistant containers to maintain its stability and efficacy.

Conflicts

  • metals
  • oxidizing agents
  • alkalis
  • amines

Safety

Safety Profile

CIR Status
Safe with restrictions
Max tested
0.3%
Sensitization risk High

The CIR Expert Panel concluded that Oxyquinoline and Oxyquinoline Sulfate are safe when used as stabilizers for hydrogen peroxide in rinse-off hair care products, with a maximum concentration of 0.3%. Critically, insufficient data exist to determine its safety in leave-on cosmetic and personal care products, prompting requests for additional information on UV absorption, phototoxicity, and potential impurities. The EU permits Oxyquinoline Sulfate at 0.3% in rinse-off hair products and 0.03% in leave-on hair products (as base). It is important to note that Oxyquinoline (the base compound) is classified by the EU as a presumed human reproductive toxicant (CMR Category 1B), although Oxyquinoline Sulfate is not similarly classified. The FDA lists Oxyquinoline Sulfate in certain OTC astringent drug products, with 575 formulations reported as of 2024 RLD data; however, this does not mitigate the CIR's significant concerns regarding its safety in leave-on skincare applications.

Your Skin

Skin Compatibility

No Normal
No Dry
No Oily
No Sensitive
Irritancy High
Comedogenicity Unknown

Our Assessment

Verdict

Avoid

Based on documented positive skin reactions at low concentrations and the critical lack of comprehensive safety data from the CIR for leave-on skincare products, Oxyquinoline Sulfate presents an unacceptable risk profile for precision skincare formulations.

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