Octocrilene
[CAS# 6197-30-4]

Identification

• Classification: Catalysts and additives >> UV absorber
• Name: Octocrilene
• Synonyms: 2-Ethylhexyl 2-cyano-3,3-diphenylpropenoate; 2-Cyano-3,3-diphenyl-2-propanoic acid 2-ethylhexyl ester
• Molecular Formula: C₂₄H₂₇NO₂
• Molecular Weight: 361.48
• CAS Registry Number: 6197-30-4
• EC Number: 228-250-8
• SMILES: CCCCC(CC)COC(=O)C(=C(C1=CC=CC=C1)C2=CC=CC=C2)C#N

Properties

• Density: 1.051
• Melting point: -10 °C
• Boiling point: 218 °C (1.5 mmHg)
• Refractive index: 1.567
• Flash point: >110 °C

Safety Data

• Hazard Symbols: GHS09 Warning
• Risk Statements: H410-H413
• Safety Statements: P273-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412

Discovery and Applications

Octocrilene is an organic compound widely recognized for its role as an active ingredient in sunscreens and cosmetic formulations due to its ability to absorb ultraviolet (UV) radiation. It is an ester formed from 2-ethylhexanol and 2-cyano-3,3-diphenylacrylic acid. Its chemical structure features conjugated double bonds that enable it to absorb UVB and short UVA radiation, making it an essential component in protecting skin from harmful sun exposure.

The discovery and development of octocrilene are tied to the increasing demand for UV protection in the mid-20th century when the harmful effects of prolonged sun exposure became better understood. UV radiation, particularly UVB (280–320 nm), is known to cause sunburn and contribute to skin cancer, while UVA (320–400 nm) penetrates deeper into the skin, causing long-term damage like aging and DNA mutations. Octocrilene was introduced as a photostable UV filter capable of absorbing these radiation wavelengths and providing long-lasting protection.

In sunscreen formulations, octocrilene is often combined with other UV filters, such as avobenzone or oxybenzone, to provide broad-spectrum protection. One of its key properties is its photostability, meaning it does not degrade quickly upon exposure to sunlight, which helps to stabilize other more sensitive UV absorbers. This property makes octocrilene a vital ingredient in formulations that aim for prolonged sun protection efficiency. It is often included in both water-resistant sunscreens and daily moisturizers with SPF.

Aside from its use in sunscreens, octocrilene also functions as an emollient in cosmetic products, providing hydration and improving the texture of formulations. Its ability to resist water makes it a valuable component in water-resistant cosmetics and skincare products. Additionally, octocrilene has been incorporated into hair care products to protect hair from the drying and damaging effects of UV exposure.

In the context of safety, octocrilene is generally considered safe for use in cosmetics and sunscreens when formulated at concentrations up to 10%. However, in recent years, concerns have emerged regarding potential environmental impacts, particularly on marine ecosystems. Studies suggest that octocrilene, like other chemical sunscreens, may contribute to coral bleaching and the degradation of aquatic environments. This has led to regulatory bodies in certain regions, such as Hawaii, to limit the use of specific chemical filters in sunscreens, including octocrilene, to protect marine life.

The application of octocrilene continues to expand as the need for effective UV protection grows, driven by increasing awareness of skin cancer risks and the rising popularity of outdoor activities. Its role in stabilizing other sunscreen ingredients, combined with its water-resistant properties, ensures that it remains a key component in the global sunscreen market.

References

2024. Thyroid, neurodevelopmental, and kidney toxicities of common organic UV filters in embryo-larval zebrafish (Danio rerio), and their potential links. Environment International, 190.
DOI: 10.1016/j.envint.2024.109030

2024. Are UV filters better together? A comparison of the toxicity of individual ultraviolet filters and off-the-shelf sunscreens to Daphnia magna. Environmental Pollution, 358.
DOI: 10.1016/j.envpol.2024.124953

1997. Sunscreens: The Molecules and Their Photochemistry. Sunscreen Photobiology: Molecular, Cellular and Physiological Aspects.
DOI: 10.1007/978-3-662-10135-3_2