Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide

Description

Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide · CAS 75980-60-8 · C22H21O2P. UNII B9EIM2D97X. Vapor Pressure: 3.045 x 10-6 Pa at 25 degrees C; pH: 4 to 5.

Identification

Computed Descriptors

Physical & Chemical Properties

Physical description & handling notes

• Large Crystals; Liquid; Liquid; CBI; Dry Powder
• Solid (yellow powder)
• Greater than 300 degrees C
• 93 degrees C (OECD Guideline 102)
• Water solubility: 3.3 mg/L at 20 °C (OECD Guideline 105, Flask method) and 11.9 mg/L at 20 °C (OECD Guideline 105, Column elution). Readily soluble in dichloromethane, acetone, n-butylacetate; soluble in styrene and in other monomers.
• 1.218 g/cm³ at 20 degrees C (OECD 109)

Regulatory Status

GHS Hazard Classification

Documented Uses

• CIR ingredient: Trimethylbenzoyl Diphenylphosphine Oxide
• Not Known or Reasonably Ascertainable
• Tanning agents not otherwise specified
• A 2021 review describes use as a photoinitiator in dental resin composites.
• The European Commission prohibited the use of TPO in cosmetic products beginning on September 1, 2025 (via the adoption of Commission Regulation (EU) 2025/877). This was the result of TPO being classified as a CMR category 1B reproductive toxicant by Commission Delegated Regulation (EU) 2024/197 under the CLP Regulation (Regulation (EC) No 1272/2008), and this classification triggered the mandatory inclusion of TPO in Annex II (prohibited substances) of the Cosmetics Regulation via Regulation (EU) 2025/877.
• Cosmetics product ingredient: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (Trimethylbenzoyl diphenylphosphine oxide)

Synonyms

75980-60-8; Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide; Phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)-; DTXSID4052502; EINECS 278-355-8; B9EIM2D97X; 2,4,6-trimethylbenzoyl diphenylphosphine oxide; trimethylbenzoyl diphenylphosphine oxide; CHIVACURE TPO; DOUBLECURE TPO; ADDITOL TPO; GENOCURE TPO; Methanone, (diphenylphosphinyl)(2,4,6-trimethylphenyl)-; DTXCID8031075; EC 278-355-8; (2,4,6-trimethylbenzoyl)diphenylphosphine oxide

Frequently Asked Questions

What are the CAS number and molecular formula of Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide?

CAS 75980-60-8; molecular formula C22H21O2P; molecular weight — g/mol.

What other names is Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide known by?

75980-60-8, Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, Phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)-, DTXSID4052502, EINECS 278-355-8, B9EIM2D97X.

What is the regulatory status of Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide?

Documented regulatory listings: CIR / INCI: Cosmetic ingredients (Trimethylbenzoyl Diphenylphosphine Oxide) -> CIR (Cosmetic Ingredient Review).

Is Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide classified as hazardous?

0.4% of GHS notifications report no hazard classification (13 of 3088).

What are the key physical properties of Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide?

Vapor Pressure: 3.045 x 10-6 Pa at 25 degrees C; pH: 4 to 5.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.