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Moumoujus

ISOPROPYLPHENYL-PROPIONALDEHYDE.

Avoid CAS 34291-99-1 / PERFUMING

ISOPROPYLPHENYL-PROPIONALDEHYDE, also known as Butylphenyl Methylpropional or Lilial, is a synthetic fragrance compound that imparts a floral, lily-like aroma. Due to significant safety concerns, including its classification as a reproductive toxicant and contact allergen, it is widely restricted or banned in many cosmetic markets.

Summary

fragrance masking

Science

Mechanism of Action

This ingredient primarily functions by delivering a floral-fresh scent to products and can also mask undesirable odors in formulations. However, its interaction with the skin can lead to sensitization, triggering allergic reactions and contact dermatitis in susceptible individuals. Animal studies have indicated its potential for reproductive toxicity, though a 2023 in vitro study found no negative effects on various cellular activities and receptor pathways at concentrations up to 100 µM.

Research

Clinical Evidence

High confidence
Effective range 2.97–18.7%
Optimal

N/A

Transparency

Dusting Analysis

Not commonly dusted

The Formula

Formulation

Solubility
Oil
Optimal pH N/A
0 7 14

Stability

ISOPROPYLPHENYL-PROPIONALDEHYDE is prone to auto-oxidation, with approximately 30% oxidation observed over 168 hours in aqueous solutions at pH 7 and 25°C, forming lysmerylic acid. To enhance stability, alpha-tocopherol (Vitamin E) is typically added at 200 ppm immediately post-production. Optimal storage involves tightly closed containers in a cool, dry, well-ventilated area, away from heat, ignition sources, and direct sunlight.

Conflicts

  • strong oxidizing agents

Safety

Safety Profile

CIR Status
Not reviewed
Pregnancy
Caution
Sensitization risk High

The Scientific Committee on Consumer Safety (SCCS) initially deemed it unsafe due to skin sensitization risk. Although a 2019 SCCS opinion suggested safety in individual products with 200 ppm alpha-tocopherol, aggregate exposure from multiple products rendered it unsafe. Critically, due to findings of reproductive toxicity in laboratory studies, the European Union officially banned its use in cosmetics and personal care products as of March 1, 2022, classifying it as a reproductive toxicant (Repr. 1B – CMR 1B). In the United States, its use is permitted under restrictions set by IFRA guidelines, without an outright FDA ban.

Your Skin

Skin Compatibility

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

Our Assessment

Verdict

Avoid

Given its classification as a reproductive toxicant, high sensitization risk, and the subsequent ban in the EU, ISOPROPYLPHENYL-PROPIONALDEHYDE is considered unsafe for use in precision skincare formulations.

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