Octyl 4-methoxycinnamate
[CAS# 5466-77-3]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Carboxylic acid and ester perfume >> Aromatic carboxylic acid ester
• Name: Octyl 4-methoxycinnamate
• Synonyms: (5-Methylheptyl) 3-(4-methoxyphenyl)-2-propenoate; 2-Ethylhexyl 4-methoxycinnamate
• Molecular Formula: C₁₈H₂₆O₃
• Molecular Weight: 290.40
• CAS Registry Number: 5466-77-3
• EC Number: 226-775-7
• SMILES: CCCCC(CC)COC(=O)/C=C/C1=CC=C(C=C1)OC

Properties

• Density: 1.009
• Boiling point: 198-200 °C
• Refractive index: 1.543-1.547
• Flash point: 193 °C
• Water solubility: <0.1 g/100 mL at 27 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H312-H315-H319-H335
• Safety Statements: P261-P280-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H312

Discovery and Applications

Octyl 4-methoxycinnamate, commonly known as octyl methoxycinnamate or OMC, is an organic compound widely recognized for its role as a UV filter in sunscreens and other cosmetic products. The discovery of this compound dates back to the late 20th century when researchers sought to develop effective ingredients for protecting the skin from harmful ultraviolet (UV) radiation. Its chemical structure comprises an octyl group attached to a 4-methoxycinnamic acid derivative, which contributes to its solubility in oil-based formulations, enhancing its efficacy as a sunscreen agent.

The primary application of octyl 4-methoxycinnamate is in the formulation of sunscreens and sun care products. It functions as a UVB absorber, effectively filtering out harmful UVB rays that are responsible for sunburn and skin damage. Its ability to absorb UV radiation in the 290-320 nm range allows it to provide broad-spectrum protection, making it a vital ingredient in many commercial sun protection products. The inclusion of octyl methoxycinnamate in formulations enhances the overall photostability and effectiveness of sunscreens, allowing for longer-lasting protection.

Beyond its use in sunscreens, octyl 4-methoxycinnamate has applications in a variety of cosmetic and personal care products. It is commonly found in moisturizers, lotions, and foundations that require sun protection properties. Its compatibility with other cosmetic ingredients and its ability to improve the sensory feel of formulations make it a popular choice among cosmetic chemists. Additionally, the compound is employed in hair care products to protect hair from UV damage, which can lead to color fading and structural deterioration.

Research into the safety and efficacy of octyl 4-methoxycinnamate has led to its approval for use in many countries, including the European Union and the United States. Regulatory bodies, including the FDA and the European Commission, have established guidelines on its concentration limits in cosmetic products to ensure consumer safety. Studies have indicated that octyl methoxycinnamate is generally well-tolerated by the skin, although some individuals may experience sensitivity or allergic reactions.

However, there has been growing concern regarding the environmental impact of octyl 4-methoxycinnamate, particularly its potential effects on marine ecosystems. Research has shown that the compound can be absorbed by aquatic organisms, leading to questions about its long-term ecological effects. As a result, some regions have started to regulate or ban the use of certain chemical sunscreens, prompting the cosmetic industry to explore alternative UV filters that are both effective and environmentally friendly.

In response to these concerns, the industry is investigating biodegradable and reef-safe alternatives to octyl 4-methoxycinnamate, which maintain effective sun protection while minimizing environmental impact. Innovative formulations incorporating natural ingredients and physical UV blockers like zinc oxide and titanium dioxide are gaining popularity as consumers become more aware of their choices and their effects on the environment.

In summary, octyl 4-methoxycinnamate is a widely used UV filter that plays a crucial role in sun protection products. Its discovery marked a significant advancement in cosmetic chemistry, providing effective protection against UV radiation. Despite its numerous applications and regulatory approvals, the potential environmental impact of octyl methoxycinnamate has sparked discussions about the need for safer alternatives in the cosmetic industry. As research continues to evolve, the future of sun protection may see a shift toward more sustainable practices without compromising efficacy.

References

2024. Thyroid, neurodevelopmental, and kidney toxicities of common organic UV filters in embryo-larval zebrafish (Danio rerio), and their potential links. Environment International.
DOI: 10.1016/j.envint.2024.109030

2024. Human exposure risk of organic UV filters: A comprehensive analysis based on primary exposure pathways. Ecotoxicology and Environmental Safety.
DOI: 10.1016/j.ecoenv.2024.116800

1991. Determination of sun-screen agents in cosmetic products by micellar liquid chromatography. Journal of Chromatography A.
DOI: 10.1016/0021-9673(91)85177-h