Benzophenone-3 vs. Benzophenone-4

Attribute	Benzophenone-3	Benzophenone-4
Synonyms	BP-3, Oxybenzone	BP-4, Sulisobenzone
Chemical Formula	C14H12O3	C14H12O4S
Molecular Weight	228.25 g/mol	284.31 g/mol
Appearance	Colorless crystals or white powder	White to pale yellow crystalline powder
Solubility	Soluble in organic solvents	Soluble in organic solvents
Usage	UV filter in sunscreens, cosmetics, and personal care products	UV filter in sunscreens, cosmetics, and personal care products
UV Absorption Range	280-350 nm	280-350 nm
Health Concerns	Potential endocrine disruptor, skin irritation	Potential endocrine disruptor, skin irritation

Introduction

Benzophenone-3 and Benzophenone-4 are two commonly used chemical compounds in the production of sunscreens and other personal care products. They belong to the family of benzophenone derivatives, which are known for their ability to absorb and filter ultraviolet (UV) radiation. In this article, we will explore the similarities and differences between these two compounds, focusing on their chemical structures, UV absorption properties, safety profiles, and applications.

Chemical Structures

Benzophenone-3, also known as Oxybenzone, has the chemical formula C14H12O3. It consists of a benzene ring with two hydroxyl groups (-OH) attached to it, as well as a ketone group (C=O) in the para position. On the other hand, Benzophenone-4, also known as Sulisobenzone, has the chemical formula C14H12O4S. It is structurally similar to Benzophenone-3, but with an additional sulfur atom (S) attached to the benzene ring. This slight difference in structure leads to variations in their properties and applications.

UV Absorption Properties

Both Benzophenone-3 and Benzophenone-4 are effective UV absorbers, capable of absorbing and filtering UV radiation. Benzophenone-3 primarily absorbs UVB rays (290-320 nm), which are responsible for sunburns and contribute to skin cancer development. It also offers some protection against UVA rays (320-400 nm), which penetrate deeper into the skin and are associated with premature aging. On the other hand, Benzophenone-4 has a broader absorption spectrum, providing protection against both UVA and UVB rays. It absorbs UVA rays more efficiently than Benzophenone-3, making it a popular choice for broad-spectrum sunscreens.

Safety Profile

When it comes to safety, both Benzophenone-3 and Benzophenone-4 have been extensively studied. However, concerns have been raised regarding the potential health risks associated with their use. Benzophenone-3 has been found to have weak estrogenic activity, meaning it can mimic the effects of the hormone estrogen in the body. This has raised concerns about its potential endocrine-disrupting effects. Additionally, some studies have suggested a possible link between Benzophenone-3 and skin allergies or irritation in certain individuals. On the other hand, Benzophenone-4 has shown a lower risk of estrogenic activity compared to Benzophenone-3. It is generally considered to be less irritating to the skin, making it a preferred choice for individuals with sensitive skin.

Applications

Both Benzophenone-3 and Benzophenone-4 find widespread use in the formulation of sunscreens, moisturizers, lip balms, and other personal care products. Benzophenone-3 is commonly used in products with SPF (Sun Protection Factor) ratings, as it provides effective UVB protection. It is also used in combination with other UV filters to enhance the overall sun protection offered by a product. On the other hand, Benzophenone-4 is often included in broad-spectrum sunscreens, as it offers protection against both UVA and UVB rays. Its broader absorption spectrum makes it a valuable ingredient in products aiming to provide comprehensive sun protection.

Conclusion

In conclusion, Benzophenone-3 and Benzophenone-4 are two benzophenone derivatives commonly used in sunscreens and personal care products. While both compounds are effective UV absorbers, they differ in their chemical structures, UV absorption properties, safety profiles, and applications. Benzophenone-3 primarily absorbs UVB rays and has been associated with potential endocrine-disrupting effects, while Benzophenone-4 offers broader protection against both UVA and UVB rays and is considered less irritating to the skin. The choice between these compounds depends on the desired level of sun protection, skin sensitivity, and specific formulation requirements. It is important for consumers to be aware of these differences and make informed decisions when selecting products containing these ingredients.