Oxybenzone
[CAS# 131-57-7]

Identification

• Classification: Chemical reagent >> Organic reagent >> Aromatic ketone
• Name: Oxybenzone
• Synonyms: 2-Hydroxy-4-methoxybenzophenone; 2-Benzoyl-5-methoxyphenol; 4-Methoxy-2-hydroxybenzophenone; HMB
• Molecular Formula: C₁₄H₁₂O₃
• Molecular Weight: 228.25
• CAS Registry Number: 131-57-7
• EC Number: 205-031-5
• SMILES: COC1=CC(=C(C=C1)C(=O)C2=CC=CC=C2)O

Properties

• Solubility: <0.1 g/100 mL (watert 20 °C, 49 mg/ml (DMSO)
• Density: 1.3 g/mL
• Melting point: 62.5 °C
• Boiling point: 150-160 °C (5 mmHg)
• Flash point: 216 °C

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H315-H319-H335-H400-H411
• Safety Statements: P261-P264-P264+P265-P271-P273-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Specific target organ toxicity - repeated exposure	STOT RE	2	H373

Discovery and Applications

Oxybenzone, also known as benzophenone-3, is a widely used organic compound known for its role as a UV filter in a variety of consumer products. This compound is particularly effective in absorbing ultraviolet (UV) radiation, making it an essential ingredient in sunscreens and other personal care products designed to protect the skin from harmful UV exposure.

The discovery of oxybenzone dates back to the early 20th century when researchers were exploring various organic compounds for their potential in UV absorption. Oxybenzone was identified for its ability to absorb UV light, which led to its development as a commercial product. The compound is synthesized through a chemical reaction that involves the condensation of benzoyl chloride with phenol, followed by additional processing to achieve the final product.

In its primary application, oxybenzone is incorporated into sunscreens and other skincare products to provide protection against UV radiation. When applied to the skin, oxybenzone absorbs UV rays and transforms them into less harmful forms of energy, thereby preventing skin damage and reducing the risk of sunburn. This protective function is crucial in preventing skin aging and lowering the risk of skin cancer associated with excessive sun exposure.

Beyond personal care products, oxybenzone is also utilized in a variety of other applications. In the field of plastics and coatings, it is employed as a UV stabilizer to protect materials from degradation caused by UV exposure. By incorporating oxybenzone into plastic formulations and coatings, manufacturers can enhance the durability and longevity of products exposed to sunlight.

Oxybenzone's application extends to the field of pharmaceuticals and other industries where UV protection is needed. In certain medical treatments, oxybenzone is used to shield sensitive compounds or formulations from UV degradation. Its effectiveness in absorbing UV radiation makes it a valuable component in these specialized applications.

Despite its benefits, there has been growing concern about the environmental and health impacts of oxybenzone. Studies have shown that the compound can be absorbed into the skin and has potential endocrine-disrupting effects. Additionally, oxybenzone has been linked to environmental issues, particularly in marine ecosystems, where it has been found to contribute to coral bleaching. As a result, there is an increasing emphasis on developing alternative UV filters and improving the safety profiles of personal care products containing oxybenzone.

Overall, oxybenzone plays a significant role in protecting human skin from UV damage and enhancing the stability of various materials exposed to sunlight. Its use in sunscreens, plastics, and other applications underscores its importance in modern consumer products and industrial processes.

References

2001. Sequential injection spectrophotometric determination of oxybenzone in lipsticks. The Analyst, 126(8).
DOI: 10.1039/b103497a

2017. Benzophenone-3 Impairs Autophagy, Alters Epigenetic Status, and Disrupts Retinoid X Receptor Signaling in Apoptotic Neuronal Cells. Molecular Neurobiology, 55(6).
DOI: 10.1007/s12035-017-0704-2

2022. Oxybenzone contamination from sunscreen pollution and its ecological threat to Hanauma Bay, Oahu, Hawaii, U.S.A. Chemosphere, 291.
DOI: 10.1016/j.chemosphere.2021.132880