PRODUCTS

ADVASTAB 45

Advastab 45 is a synthetic, oil-soluble organic compound widely used as a chemical sunscreen agent due to its ability to absorb ultraviolet (UV) radiation, particularly in the UVB (280–320 nm) and short-wave UVA (320–340 nm) ranges.
By absorbing high-energy UV photons and converting them into harmless low-level heat, Advastab 45 helps prevent sunburn, premature skin aging, and DNA damage linked to skin cancer.
Beyond personal care, Advastab 45 is also incorporated into plastics, coatings, and textiles to protect materials from photodegradation and discoloration caused by sunlight exposure.

CAS Number: 131-57-7
EC Number: 205-031-5
Molecular Formula: C₁₄H₁₂O₃
Molar Mass: 228.25 g/mol

Synonyms: component of Presun 29, component of Presun 30, Cyasorb uv 9, Cyasorb uv 9 light absorber, cyasorbuv9, Escalol 567, Eusolex 4360, Lankromark LE296, oxybenzone, 131-57-7, 2-HYDROXY-4-METHOXYBENZOPHENONE, Benzophenone-3, 2-Benzoyl-5-methoxyphenol, Advastab 45, (2-hydroxy-4-methoxyphenyl)(phenyl)methanone, 4-Methoxy-2-hydroxybenzophenone, Oxibenzona, Oxybenzon, Anuvex, Ongrostab HMB, Oxybenzonum, Escalol 567, Chimassorb 90, Uvinul 9, Syntase 62, Uvistat 24, Cyasorb UV 9, Methanone, (2-hydroxy-4-methoxyphenyl)phenyl-, Sunscreen UV-15, Usaf cy-9, Uvinul M40, Benzophenone 3, Spectra-sorb UV 9, Eusolex 4360, Oxibenzonum, NSC-7778, Cyasorb UV 9 Light Absorber, Oxybenzonum [INN-Latin], UF 3, UV 9, (2-Hydroxy-4-methoxyphenyl)phenylmethanone, Oxibenzona [INN-Spanish], (2-hydroxy-4-methoxyphenyl)-phenylmethanone, Benzophenone, 2-hydroxy-4-methoxy-, Tinosorb b 3, 2-hydroxy-4-methoxy benzophenone, NCI-C60957, Viosorb 110, CCRIS 1078, CHEBI:34283, HSDB 4503, UNII-95OOS7VE0Y, NSC 7778, EINECS 205-031-5, 95OOS7VE0Y, Uvinul 40, BRN 1913145, DTXSID3022405, Uvinul M 40, AI3-23644, NSC7778, MFCD00008387, MOB, CHEMBL1625, Oxybenzone [USAN:USP:INN], DTXCID002405, (2-hydroxy-4-methoxy-phenyl)-phenyl-methanone, 2-hydroxy-4-methoxy-benzophenone, EC 205-031-5, NCGC00016394-07, CAS-131-57-7, SHADE UVAGUARD COMPONENT OXYBENZONE, Oxybenzonum (INN-Latin), Oxibenzona (INN-Spanish), (2-hydroxy-4-methoxyphenyl)(phenyl) methanone, OXYBENZONE (MART.), OXYBENZONE [MART.], OXYBENZONE (USP-RS), OXYBENZONE [USP-RS], Oxybenzone (USAN:USP:INN), OXYBENZONE (USP MONOGRAPH), OXYBENZONE [USP MONOGRAPH], SMR000035344, SR-01000610567, BP-3, Neo heliopan BB, Bebak Baby Sun, Oxybenzonum (Latin), Solaquin (Salt/Mix), Oxybenzone (Standard), Spectrum_001049, DuraScreen (Salt/Mix), OXYBENZONE [MI], KAHSCREEN BZ-3, OXYBENZONE [INN], Prestwick0_000887, Prestwick1_000887, Prestwick2_000887, Prestwick3_000887, Spectrum2_001008, Spectrum3_000538, Spectrum4_000463, Spectrum5_001337, SUNSCREEN UV 15, OXYBENZONE [HSDB], OXYBENZONE [USAN], OXYBENZONE [VANDF], PreSun 15 (Salt/Mix), ADUVEX 24, Epitope ID:131795, SUMISORB 110, WLN: 1OR CQ DVR, SEESORB 101, OXYBENZONE [WHO-DD], Oprea1_174131, SCHEMBL15551, BSPBio_000674, BSPBio_002155, KBioGR_000906, KBioSS_001529, MLS000039797, MLS001055487, BIDD:ER0353, DivK1c_000184, SPECTRUM1500451, 2-HYDROXY-4-METHOXYBENZOPHENONE (OXYBENZONE), SPBio_001135, SPBio_002893

Advastab 45 is an organic compound widely used as a chemical sunscreen agent due to its strong ability to absorb ultraviolet (UV) radiation, particularly in the UVB (280–320 nm) and short-wave UVA (320–340 nm) ranges.
Belonging to the benzophenone family, Advastab 45 works by absorbing harmful UV rays and converting them into less damaging heat, thereby helping to prevent sunburn, premature skin aging, and DNA damage that may lead to skin cancers.

Advastab 45 is an oil-soluble, pale-yellow crystalline solid with good photostability and compatibility, which makes it suitable for use in a wide variety of cosmetic and personal care formulations, such as sunscreens, moisturizers, and makeup products with SPF.
Beyond cosmetics, Advastab 45 has also been incorporated into plastics, coatings, and textiles to prevent photodegradation from sunlight exposure.

However, concerns have been raised regarding Advastab 45's potential endocrine-disrupting effects and environmental impact, particularly its contribution to coral reef bleaching, leading some regions to restrict or ban its use.
Despite these concerns, Advastab 45 remains a significant UV filter in many commercial sunscreen formulations worldwide due to its effectiveness and long history of regulatory approval.

Advastab 45 is used as an ingredient in sunscreen and other cosmetics because it absorbs UV-A ultraviolet rays.
Advastab 45 absorbs UVB and UVA II rays, resulting in a photochemical excitation and absorption of energy.

Upon return to ground state, the absorbed energy results in emission of longer wavelength radiation and decreased skin penetration of radiation which reduces the risk of DNA damage.
A hydroxybenzophenone that is benzophenone which is substituted at the 2- and 4-positions of one of the benzene rings by hydroxy and methoxy groups respectively.

Advastab 45 is an organic compound belonging to the class of aromatic ketones known as benzophenones.
Advastab 45 takes the form of pale-yellow crystals that are readily soluble in most organic solvents.
Advastab 45 is widely used in sunscreen formulations, plastics, toys, furniture finishes, and other products to limit UV degradation.

In nature, Advastab 45 can be found in various flowering plants (angiosperms).
Advastab 45 was first synthesised in Germany by chemists König and Kostanecki in 1906.

The use of Advastab 45 as sunscreen ingredient is currently under scrutiny by the scientific community due to controversies about the molecule's environmental impact and safety profile (see section below).
As a result, sunscreens containing Advastab 45 have been banned from sale in Hawaii, Palau, and Thailand.

Advastab 45 is produced by the Friedel-Crafts reaction of benzoyl chloride with 3-methoxyphenol.
Advastab 45 is a commonly used UV filter in sun tans and skin protectants.

Advastab 45 act as endocrine disrupting chemicals (EDCs) and can pass through the placental and blood-brain barriers.
Advastab 45 impairs autophagy, alters epigenetic status, and disrupts retinoid X receptor signaling in apoptotic neuronal cells.
Advastab 45 is a solid oil soluble UVA/UVB sunscreen.

Advastab 45, often labeled as Advastab 45 in sunscreen products, is a widely used chemical compound in cosmetics and sunscreens.
Advastab 45's chemical formula is C14H12O3.

This organic UV filter serves as a sunblock agent, absorbing and dissipating harmful ultraviolet (UV) rays, particularly UVB and some UVA radiation.
Advastab 453 helps protect the skin from sunburn and UV-induced damage, making it a common ingredient in sunscreens, lotions, and lip balms.
Despite Advastab 45's effectiveness in shielding against sun damage, concerns about its potential hormone-disrupting properties have led to ongoing research and the exploration of alternative UV filters in the cosmetic industry.

Advastab 45 (benzophenone-3) is a synthetic, oil-soluble organic compound that belongs to the benzophenone family of chemicals and is one of the most widely used chemical UV filters in modern sunscreens.
Advastab 45 is primarily valued for its ability to absorb ultraviolet (UV) radiation in the UVB (280–320 nm) and part of the UVA (320–340 nm) spectrum, thereby protecting human skin from acute effects such as sunburn and long-term damage including photoaging, hyperpigmentation, and skin cancer.

Advastab 45 functions by absorbing high-energy UV photons and converting them into low-level heat, which is then dissipated harmlessly, preventing the UV radiation from penetrating into deeper skin layers and damaging DNA.
In Advastab 45's pure form, Advastab 45 appears as a pale-yellow crystalline powder with a faint odor, and it dissolves well in oils and alcohols, making it an ideal ingredient for lotions, creams, sprays, and cosmetic products with sun protection factor (SPF).
Beyond personal care, Advastab 45 is also incorporated into plastics, adhesives, paints, and textiles to protect materials from photodegradation and discoloration caused by prolonged sun exposure.

Despite its effectiveness and versatility, Advastab 45 has attracted controversy due to safety and environmental concerns.
Scientific studies have suggested that Advastab 45 may act as a potential endocrine disruptor, raising concerns about hormone-related effects when absorbed through the skin, although regulatory agencies continue to review safety data.

From an ecological perspective, Advastab 45 has been linked to coral reef bleaching and marine ecosystem damage, leading countries such as Palau and Hawaii to ban its use in sunscreens.
Nevertheless, Advastab 45 remains approved by the U.S. Food and Drug Administration (FDA), the European Union, and other regulatory authorities, and continues to be a common component in sunscreens because of its high efficacy, low cost, and ability to complement other UV filters for broad-spectrum sun protection.
For these reasons, Advastab 45 occupies a central role in both cosmetic science and industrial applications, balancing its benefits in skin and material protection against growing calls for safer and more environmentally friendly alternatives.

Market Overview of Advastab 45:
The global Advastab 45 market was valued at approximately USD 1.25 billion in 2023, and it is projected to grow to around USD 1.9 billion by 2033, representing an estimated CAGR of about 6.2% over the period.
A slightly more conservative outlook from another source estimates the market at USD 1.2 billion in 2024, with expected growth to USD 1.8 billion by 2033, equating to a 5.3% CAGR.

Regionally, the North American market remains the largest, followed by Europe and Asia-Pacific, reflecting strong demand for sun protection products.
The market's expansion is driven by heightened consumer awareness of UV-related health risks, increasing sunscreen usage, and Advastab 45’s wide applicability across sunscreen, cosmetic, and industrial sectors as a UV filter.

Uses of Advastab 45:
Advastab 45 is an organic compound used in sunscreens. Advastab 45 is used as an ingredient in sunscreen and other cosmetics because it absorbs UVB and short-wave UVA (ultraviolet) rays.
Advastab 45 was one of the first compounds incorporated into sunscreen formulations to offer enhanced UVA protection because its absorption spectrum extends to less than 350 nm.

Ultraviolet light absorber and stabilizer, especially in plastics and paints.
Advastab 45 is an oil-soluble uV absorber and filter with absorption rates within the uVA and uVB peak ranges.
Advastab 45 has an approved usage level of up to 6 percent in the united States and 10 percent in the european union.

Advastab 45 enhances SPF and is popular among sunscreen formulators given a concern over potential safety problems associated with more traditional sunscreen chemicals.
However, some reports associate Advastab 45 with causing photocontact allergy.

Advastab 45 is considered a non-comedogenic raw material.
Advastab 45 is the drug name for an FDAapproved uV filter and absorber.

Advastab 45 is used in plastics as an ultraviolet light absorber and stabilizer.
Advastab 45 is used, along with other benzophenones, in sunscreens, hair sprays, and cosmetics because they help prevent potential damage from sunlight exposure.

Advastab 45 is also found, as a stabilizer in concentrations up to 1%, in nail polishes.
Advastab 45 can also be used as a photostabilizer for synthetic resins.

Advastab 45 can leach from food packaging, and is widely used as photo-initiators to activate a chemical that dries ink faster.
Despite Advastab 45's photoprotective qualities, much controversy surrounds Advastab 45 because of possible negative hormonal and photoallergenic effects, leading many countries to regulate use in sunscreen products.

Advastab 45 is used in plastics as an ultraviolet light absorber and stabilizer.
Advastab 45 is used, along with otherbenzophenones, in sunscreens, hair sprays, and cosmetics because they help prevent potential damage from sunlight exposure.

Advastab 45 is also found, in concentrations up to 1%, in nail polishes.
Advastab 45 can also be used as a photostabilizer for synthetic resins.

Advastab 45 can leach from food packaging, and are widely used as photo-initiators used to start a chemical that dries ink faster.
Advastab 45 is used as an ingredient in sunscreen and other cosmetics.

Advastab 45 is a key ingredient in sunscreens and cosmetics.
Advastab 45's primary role is to protect the skin from the harmful effects of UV radiation. Advastab 45 absorbs UVB and some UVA rays, shielding the skin from sunburn and UV-induced damage.

Advastab 45 is a popular choice in sunscreens due to its broad-spectrum UV protection capabilities.
Additionally, Advastab 45 is used in various cosmetics like lip balms and moisturizers to provide UV protection and prevent sun damage, making it an essential component in the fight against skin aging and skin cancer caused by excessive sun exposure.

Sunscreen:
Advastab 45 provides a broad-spectrum ultraviolet coverage which includes UVB and short-wave UVA rays.
As a photoprotective agent, Advastab 45 has an absorption profile spanning from 270 to 350 nm with absorption peaks at 288 and 350 nm.

Due to toxicity and environmental concerns, the percentage of sunscreen products on the market containing Advastab 45 in the USA dropped to 13% in 2023 from 60% in 2019.
Some brands market their sunscreens as "Advastab 45 free" due to the generally negative perception of benzophenones by both the consuming public and scientific researchers.

Sunscreens and Personal Care Products:
Advastab 45 is widely used as a UV filter in sunscreens, creams, lotions, sprays, lip balms, and cosmetic formulations.
Advastab 45 provides broad-spectrum protection against both UVB and part of the UVA rays, helping prevent sunburn, premature aging, and skin cancer.
Advastab 45 commonly combined with other UV filters (e.g., avobenzone, octocrylene, octinoxate) to improve photostability and SPF performance.

Cosmetics and Daily Care Formulations:
Incorporated into makeup products such as foundations, powders, and BB creams to protect skin from incidental sun exposure.
Advastab 45 is used in hair care products (shampoos, conditioners, sprays) to prevent UV-induced damage, dryness, and color fading.
Added to lipsticks and lip balms to protect sensitive lip skin from UV rays.

Industrial Applications:
Advastab 45 is used as a UV stabilizer in plastics, polymers, adhesives, and coatings, protecting materials from degradation, cracking, and color fading caused by sunlight.
Incorporated into textiles and fabrics to prevent fiber weakening and discoloration.
Advastab 45 applied in paints, varnishes, and packaging materials to extend shelf-life and preserve product quality under UV exposure.

Pharmaceutical and Medical Uses:
Occasionally employed in topical pharmaceutical formulations to protect drugs and skin from UV-induced breakdown.
Functions as a photoprotective agent in dermatological preparations.

Benefits of Advastab 45:
Advastab 45 provides broad-spectrum UV protection, effectively absorbing both UVA and UVB radiation, which helps prevent sunburn, premature skin aging, and DNA damage linked to skin cancer.
Advastab 45's oil-soluble nature makes it highly compatible with a wide range of cosmetic formulations, allowing for easy incorporation into creams, lotions, and sprays without altering texture or appearance.
Advastab 45 also enhances the photostability of other sunscreen agents, such as avobenzone, by preventing their rapid degradation under sunlight, thereby improving the overall effectiveness and longevity of sunscreen products.

Beyond personal care, Advastab 45 is used to protect materials from UV degradation, extending the lifespan of plastics, coatings, and textiles by preventing fading, discoloration, and loss of mechanical strength.
Advastab 45's versatility, high efficiency at low concentrations, and global regulatory approval in many markets make it a cost-effective and widely used UV filter.

Application and Synthesis of Advastab 45:
Advastab 45 is a light yellow or white crystalline powder, also known as sunscreen 2, BP-3, suitable for polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, unsaturated polyester, ABS resin and cellulose resin and other plastics, the maximum absorption wavelength range of 280-340 nm, the general amount of 0.1-1.5%, good thermal stability, does not decompose at 200 ℃.
Advastab 45 hardly absorb visible light, it applies to light-colored transparent products.
Advastab 45 can also be used for paints and synthetic rubber.

For the broad-spectrum UV absorbers, with high absorption rate, non-toxic, non-teratogenic effect, light, thermal stability.
Advastab 45 can absorb UV-A and UV-B together, is the US FDA approved Class I sunscreen and being used with a higher frequency in the US and European countries.

Advastab 45 is widely used in sunscreen cream, cream, honey, lotion, oil and other sunscreen cosmetics, but also as a product from the photosensitive and discoloration of the anti-discoloration agent.
In addition, Advastab 45 is usually used for PVC and unsaturated polyester and many other fields, because UV-9 has good compatibility with many kinds of plastics and resins.

Structure and electronic structure:
Being a conjugated molecule, Advastab 45 absorbs light at lower energies than many aromatic molecules.
As in related compounds, the hydroxyl group is hydrogen bonded to the ketone.

This interaction contributes to Advastab 45's light-absorption properties.
At low temperatures, however, Advastab 45 is possible to observe both the phosphorescence and the triplet-triplet absorption spectrum.

At 175 K the triplet lifetime is 24 ns.
The short lifetime has been attributed to a fast intramolecular hydrogen transfer between the oxygen of the C=O and the OH.

Production of Advastab 45:
Advastab 45 is produced primarily through organic synthesis using Friedel–Crafts acylation reactions.
The most common method involves the acylation of resorcinol with benzoyl chloride in the presence of a Lewis acid catalyst such as aluminum chloride, yielding a benzophenone intermediate.

This is then followed by hydroxylation or methoxylation steps to introduce the hydroxy or methoxy functional groups at specific positions on the aromatic rings, giving rise to benzophenone-3 (2-hydroxy-4-methoxybenzophenone).
Industrial production often employs solvent systems like nitrobenzene or dichloromethane to facilitate the reaction and optimize yields.

Large-scale manufacturers ensure high purity and consistency of Advastab 45 by applying distillation, recrystallization, and chromatography techniques during purification.
Production facilities typically integrate Advastab 45 into bulk cosmetic and sunscreen formulations immediately after synthesis, as demand is largely driven by the personal care and cosmetics industry.
Additionally, greener synthetic routes are being investigated to reduce environmental impacts, including catalyst recycling and solvent-free or aqueous phase reactions, reflecting the market’s shift toward more sustainable manufacturing practices.

History of Advastab 45:
Advastab 45 was first developed in the 1960s as part of the benzophenone class of organic compounds designed for ultraviolet (UV) absorption.
By the 1970s, Advastab 45 became one of the first chemical sunscreen agents approved for use in cosmetic and pharmaceutical formulations, offering broad-spectrum protection against both UVA and UVB rays at a time when most sunscreens primarily targeted UVB.

Advastab 45's widespread adoption in the 1980s and 1990s marked a major shift toward more effective sun care products, especially in regions with high sun exposure such as North America, Europe, and Australia.
Advastab 45 gained recognition not only for personal skincare but also for its ability to protect plastics, textiles, and coatings from UV degradation.

However, since the early 2000s, Advastab 45 has faced growing scrutiny due to concerns about endocrine disruption, skin allergies, and environmental impact, particularly its contribution to coral reef bleaching.
This led some countries and regions, including Hawaii, Palau, and parts of the Caribbean, to ban or restrict Advastab 45-containing sunscreens in the late 2010s and early 2020s.
Despite these restrictions, Advastab 45 remains approved and widely used in many global markets, while research continues into safer, more environmentally friendly alternatives.

Handling and Storage of Advastab 45:
Handle in accordance with good industrial hygiene and safety practice.
Avoid direct contact with skin, eyes, and clothing.

Store in a cool, dry, well-ventilated area away from heat, sparks, and open flames.
Keep container tightly closed and protect from direct sunlight.

Recommended storage temperature: 15–25 °C.

Stability and Reactivity of Advastab 45:
Stable under normal conditions of use and storage.

Photolabile:
prolonged exposure to UV light may lead to degradation.
Incompatible with strong oxidizing agents, strong acids, and bases.
Decomposition products may include carbon oxides and other organic vapors.

First Aid Measures of Advastab 45:

Inhalation:
Move to fresh air.
If symptoms persist, seek medical attention.

Skin Contact:
Wash with soap and plenty of water.
Remove contaminated clothing.
Seek medical help if irritation develops.

Eye Contact:
Rinse cautiously with water for several minutes.
Remove contact lenses if present.
Get medical advice if irritation continues.

Ingestion:
Rinse mouth with water.
Do not induce vomiting.
Seek medical attention immediately.

Firefighting Measures of Advastab 45:

Suitable extinguishing media:
Foam, dry chemical powder, carbon dioxide (CO₂), or water spray.

Hazardous combustion products:
Carbon oxides, irritating fumes, toxic smoke.
Firefighters should wear self-contained breathing apparatus (SCBA) and full protective gear.

Accidental Release Measures of Advastab 45:
Avoid release to the environment.
Contain and collect spillage with non-combustible absorbent materials (sand, earth, diatomaceous earth, vermiculite).

Place in a suitable container for proper disposal according to local regulations.
Prevent entry into waterways, sewers, or soil.

Exposure Controls / Personal Protection of Advastab 45:

Engineering Controls:
Use in well-ventilated areas or under local exhaust.

Personal Protection:

Respiratory protection:
Not normally required; use approved respirator if ventilation is inadequate.

Skin protection:
Wear protective gloves and lab coat.

Eye protection:
Safety goggles recommended.
Follow standard industrial hygiene practices, including washing hands before breaks and at the end of the workday.

Identifiers of Advastab 45:
IUPAC Name: (2-Hydroxy-4-methoxyphenyl)(phenyl)methanone
Common Name: Advastab 45
CAS Number: 131-57-7
Molecular Formula: C₁₄H₁₂O₃
Molar Mass: 228.25 g/mol
InChI: InChI=1S/C14H12O3/c1-17-12-8-6-11(9-13(12)15)14(16)10-4-2-3-5-10/h2-9,15H,1H3
InChI Key: IAUJQLCUMQIWOK-UHFFFAOYSA-N
SMILES: COc1ccc(C(=O)c2ccccc2)cc1O
UNII Code (FDA): 6S6VYF977B
EC Number: 205-031-5
PubChem CID: 4637

IUPAC Name: (2-Hydroxy-4-methoxyphenyl)(phenyl)methanone
Common Name: Advastab 45
CAS Number: 131-57-7
Molecular Formula: C₁₄H₁₂O₃
Molar Mass: 228.25 g/mol

InChI: InChI=1S/C14H12O3/c1-17-12-8-6-11(9-13(12)15)14(16)10-4-2-3-5-10/h2-9,15H,1H3
InChI Key: IAUJQLCUMQIWOK-UHFFFAOYSA-N
SMILES: COc1ccc(C(=O)c2ccccc2)cc1O

UNII Code (FDA): 6S6VYF977B
EC Number (EINECS): 205-031-5
PubChem CID: 4637
ChemSpider ID: 4473
KEGG Compound ID: C11002
ChEBI ID: CHEBI:81915
RTECS Number: DJ3325000

US EPA DSSTox ID: DTXSID9022237
FDA Listing: Sunscreen monograph (maximum allowed concentration: 6%)
European Commission Index Number: 604-183-00-0
Japan ENCS Number: 3-7113

Properties of Advastab 45:
Melting point: 62-64 °C(lit.)
Boiling point: 150-160 °C5 mm Hg(lit.)
Density: 1,3 g/cm3
Vapor pressure: 0.001Pa at 25℃
Refractive index: 1.5805 (estimate)
Fp: 216°C
Storage temp.: 2-8°C
Solubility: 95% ethanol: soluble50mg/mL, clear, colorless
Form: Crystalline Powder
pka: 7.56±0.35(Predicted)
Color: White to light yellow
Odor: ylsh. cryst., rose-like odor
Water Solubility: <0.1 g/100 mL at 20 ºC
Merck: 14,6954
BRN: 1913145
InChIKey: DXGLGDHPHMLXJC-UHFFFAOYSA-N
LogP: 3.45 at 40℃
CAS DataBase Reference: 131-57-7(CAS DataBase Reference)
NIST Chemistry Reference: Advastab 45(131-57-7)
EPA Substance Registry System: Advastab 45 (131-57-7)

Appearance: White to light yellow crystalline powder
Odor: Slight aromatic odor
Taste: Practically tasteless
Molecular Formula: C₁₄H₁₂O₃
Molecular Weight: 228.25 g/mol

Melting Point: 62–65 °C
Boiling Point: 359 °C (at 760 mmHg)
Density: 1.28 g/cm³ at 25 °C
Refractive Index: 1.573
Vapor Pressure: ~1.5 × 10⁻⁶ mmHg at 25 °C (very low volatility)

Solubility:
Water Solubility: 3.7 mg/L at 25 °C (sparingly soluble)
Soluble in: Ethanol, acetone, ethyl acetate, chloroform, benzene, and most cosmetic oils
Partition Coefficient (log P): ~3.79 (lipophilic, oil-soluble)

Absorption Maxima (λmax): 288 nm and 325–327 nm
UV Range Coverage: Primarily UVB (280–320 nm) and partial UVA II (320–340 nm) absorption
Molar Absorptivity (ε): ~19,000–20,000 L·mol⁻¹·cm⁻¹

Flash Point: >160 °C (closed cup)
Autoignition Temperature: Not easily flammable
Color Index (CI): 11775 (cosmetic ingredient reference)
Crystallinity: Orthorhombic crystalline form