Science
Mechanism of Action
This ingredient acts as a biocide by disrupting the cellular membrane and interfering with essential metabolic processes of various microorganisms. This action leads to the inactivation or death of bacteria, fungi, and other microbes.
Research
Clinical Evidence
High confidence0.15% (leave-on products)
Key findings
- 01 SCCS Opinion (2015, 2024)
Transparency
Dusting Analysis
As a cosmetic preservative, O-Phenylphenol's inclusion is governed by strict regulatory limits established by authorities like the SCCS. Its usage is driven by functional necessity within these defined maximum concentrations, making 'dusting' below an effective threshold unlikely. Exceeding the specified percentages would be an issue of safety rather than mere ineffectiveness.
The Formula
Formulation
Stability
O-Phenylphenol is chemically stable under standard ambient conditions. It exhibits poor solubility in water (approximately 0.560 g/L) but is readily soluble in various organic solvents, consistent with its lipophilic nature (log Pow 3.12-3.18). Its sodium salt is water-soluble with a highly alkaline pH (12.0-13.5).
Conflicts
- Strong oxidizing agents
- Strong bases
- Strong reducing agents
- Concentrated sulfuric acid
- Nitrating agents
Safety
Safety Profile
The Scientific Committee on Consumer Safety (SCCS) deems O-Phenylphenol safe for use as a preservative up to 0.15% in leave-on products and 0.2% in rinse-off products; however, its salts are prohibited. Although it absorbs rapidly through human skin (approx. 43%), efficient excretion minimizes systemic accumulation. Undiluted forms can cause significant skin and eye irritation or even be corrosive. It has been identified as a suspected endocrine disruptor, prompting revised concentration limits. Chronic toxicity studies in rodents indicated tumorigenic effects at very high doses in the urinary bladder and kidneys, attributed to a non-genotoxic, sex/species-specific mechanism. Skin discoloration is a potential side effect.
Your Skin
Skin Compatibility
Our Assessment
Verdict
While O-Phenylphenol is an effective preservative approved within specific regulatory limits, its classification as a suspected endocrine disruptor and high irritancy potential in concentrated forms warrant careful consideration for precision skincare formulations.
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References
Sources