Ultraviolet (UV) radiation from sunlight can be divided into UVA, UVB, and UVC according to wavelength, and is a major factor in sunburn, photoaging, and even skin cancer. UVA (320–400 nm) penetrates deeply into the dermis, contributing to long-term pigmentation and photoaging, while UVB (290–320 nm) primarily affects the epidermis, causing redness and sunburn. The following provides a systematic overview of mainstream chemical sunscreen ingredients currently available on the market and their key properties.

UVA Absorbers

1. Avobenzone (Butyl Methoxydibenzoylmethane)

CAS No.: 70356-09-1

Molecular Formula: C20H22O3

Appearance: White to Pale Yellow Solid

Solubility: Chloroform (Slightly), DMSO (Slightly), Methanol (Slightly, Heated, Sonicated)

Key Features:

Avobenzone is a full-spectrum UVA filter with one of the widest absorption ranges among sunscreen agents, covering 320–400 nm with peak efficacy around 360 nm. However, due to its high photosensitivity, it is typically combined with photostabilizers to enhance stability and prolong protection. Regulatory approvals allow its use at concentrations of up to 3% in the United States and 5% in the European Union.

2. Diethylamino hydroxybenzoyl hexyl benzoate (DHHB)

CAS No.: 302776-68-7

Molecular Formula: C24H31NO4

Appearance: White to Yellow Solid

Solubility: Acetonitrile (Slightly), Chloroform (Slightly), DMSO (Slightly)

Key Features:

Diethylamino Hydroxybenzoyl Hexyl Benzoate is a UVA filter with a peak absorption at 354 nm and significantly greater photostability compared to Avobenzone. Currently Diethylamino hydroxybenzoyl hexyl benzoate is not an FDA-approved sunscreen agent in the United States; however, it is an approved UV filter in many other markets, including the European Union, China, Australia, and Japan for use at concentrations of up to 10%, either as a standalone agent or in combination with other UV filters.
Huateng Pharma supplies high-quality Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB), fully ✅ REACH registered, to support your sunscreen and skincare formulation needs.

3. Terephthalylidene dicamphor sulfonic acid

CAS No.: 90457-82-2

Molecular Formula: C28H34O8S2

Key Features:

Terephthalylidene Dicamphor Sulfonic Acid, marketed as Mexoryl SX, is a highly effective water-soluble sunscreen agent that specifically targets UVA-1 rays (320–400 nm). Known for its excellent photostability and compatibility in formulations, it is widely incorporated into both sun care and anti-aging skincare products. It is approved for use as a UV filter in the European Union at concentrations of up to 10%. While FDA-approved as a sunscreen active, its commercial availability in the United States remains limited.

UVB Absorbers

1. Octinoxate (Octyl methoxycinnamate)

CAS No.: 5466-77-3

Molecular Formula: C18H26O3

Appearance: Colourless or pale yellow liquid

Solubility: Chloroform (Slightly), Methanol (Slightly)

Key Features:

Octinoxate is the most widely used UVB filter worldwide, with a peak absorption around 311 nm. It offers strong protective efficacy with low irritation and demonstrates excellent compatibility, often used in combination with UVA filters such as Avobenzone to enhance overall sun protection. With outstanding photostability, it is suitable for various formulations, including lotions, creams, and sprays.

2. Diethylhexyl Butamido Triazone

CAS No.: 154702-15-5

Molecular Formula: C44H59N7O5

Appearance: White to Off-White solid

Solubility: Chloroform (Slightly), DMSO (Slightly)

Key Features:

Diethylhexyl Butamido Triazone (Iscotrizinol) is an oil-soluble organic UV filter that primarily absorbs UVB radiation with a peak protection at 310 nm. Highly efficient, it requires only low concentrations to deliver strong SPF protection. Its oil solubility makes it especially suitable for long-lasting, water-resistant, and water-repellent sunscreen formulations.

3. Ensulizole (2-Phenylbenzimidazole-5-sulfonic acid)

CAS No.: 27503-81-7

Molecular Formula: C13H10N2O3S

Appearance: White Fine Crystalline Powder

Solubility: ethanol and water: soluble (as sodium salt)

Key Features:

Ensulizole is a water-soluble UVB filter with a peak absorption around 302 nm. Unlike most oil-soluble sunscreen agents, it can be incorporated into the water phase of emulsions, enabling a less greasy, more aesthetically pleasing formulation such as a daily use moisturizer containing sunscreen. Its water solubility also makes it suitable for clear gel formulations. In addition, Ensulizole enhances the SPF performance of both organic and inorganic sunscreens. It is approved for use at concentrations of up to 4% in the United States and up to 8% in the European Union.

4. Ethylhexyl Triazone

CAS No.: 88122-99-0

Molecular Formula: C48H66N6O6

Appearance: White to Light yellow solid

Solubility: DMSO : 30 mg/mL (36.45 mM)

Key Features:

Ethylhexyl Triazone (Octyl Triazone) is a next-generation triazine-based UVB filter and the most powerful oil-soluble UVB absorber currently available. With excellent photostability and a peak absorption around 314 nm, it provides highly effective UVB protection and significantly boosts SPF values. It also demonstrates strong water resistance and high affinity for skin keratin, helping to prevent UVB-induced immunosuppression. Thanks to its outstanding stability, particularly in hot and humid environments, it is often combined with UVA filters to deliver broad-spectrum sun protection.

5. Homosalate

CAS No.: 118-56-9

Molecular Formula: C16H22O3

Appearance: A colourless liquid.

Solubility:  Chloroform (Slightly), DMSO (Slightly)

Key Features:

Homosalate is a UVB filter that absorbs wavelengths in the 295–315 nm range, with peak absorption at 306 nm. Classified by the FDA as a Category I sunscreen ingredient, it is approved for use at concentrations of 4–15% in the United States and up to 10% under the European Union Cosmetic Directive.

6. Ethylhexyl salicylate

CAS No.: 118-60-5

Molecular Formula: C15H22O3

Appearance: A colourless liquid.

Solubility: Chloroform (Slightly), Ethyl Acetate (Slightly)

Key Features:

Ethylhexyl Salicylate is an auxiliary UVB filter with a peak absorption around 305 nm. It is often combined with other sunscreen agents to enhance SPF performance. Approved by the FDA, it absorbs across the entire UVB range and is permitted for use at concentrations of 3–5% in both the United States and the European Union.

UVA & UVB Absorbers

1. Octocrylene

CAS No.: 6197-30-4

Molecular Formula: C24H27NO2

Appearance: Colourless to Light Yellow

Solubility: Chloroform (Slightly), Methanol (Sparingly)

Key Features:

Octocrylene (OCR) is a commonly used oil-soluble UV filter that absorbs across the 250–360 nm range, providing protection against both UVB and part of the UVA spectrum, with a peak absorption around 303 nm. It is highly effective, offering strong absorption capacity, excellent photothermal stability, and the ability to achieve high SPF values. Octocrylene is considered safe, non-toxic, and non-teratogenic, though it is a relatively costly ingredient. It is approved for use at concentrations of 7–10% in both the United States and the European Union.

2. Bisoctrizole

CAS No.: 103597-45-1

Molecular Formula: C41H50N6O2

Appearance: White to Orange to Green Solid

Solubility:  Almost transparency in THF

Key Features:

Bisoctrizole, marketed as Tinosorb M, is a broad-spectrum benzotriazole-based UV filter that covers the full 280–400 nm range. Unique among organic filters, it provides protection by absorbing, reflecting, and scattering both UVA and UVB radiation. While not approved by the FDA, it is permitted for use in the European Union and several other regions at concentrations of up to 10% in sunscreens, daily skincare, and skin-lightening products.

3. Bemotrizinol

CAS No.: 187393-00-6

Molecular Formula: C38H49N3O5

Appearance: Light Yellow to Yellow solid

Solubility: Chloroform (Slightly), Ethyl Acetate (Slightly)

Key Features:

Bemotrizinol is a broad-spectrum UV filter that effectively absorbs both UVB and UVA radiation, with absorption peaks at 310 nm and 340 nm. It is exceptionally photostable, retaining 98.4% of its activity even after exposure to 50 minimal erythemal doses (MEDs). In addition to its strong UV protection, it stabilizes other sunscreen actives such as Avobenzone by preventing photodegradation. Bemotrizinol is approved for use in Europe and Australasia and is marketed under the trade names Tinosorb S and Escalol S. While widely regarded as one of the most effective modern UV filters, it is not yet approved by the FDA and therefore unavailable in the United States.

4. Oxybenzone

CAS No.: 131-57-7

Molecular Formula: C14H12O3

Appearance: White to light yellow crystalline powder

Solubility: 95% ethanol: soluble 50 mg/mL, clear, colorless

Key Features:

Oxybenzone absorbs UVB and UVA II rays, resulting in a photochemical excitation and absorption of energy. is an oil-soluble UV absorber and filter with absorption rates within the UV-A and UV-B peak ranges. It has an approved usage level of up to 6% in the United States and 10% in the European Union.