OP-21, full name Octylphenol Ethoxylate (21) (CAS No.: 9036-19-5), is a classic nonionic surfactant produced by Guoli Chemical. Its molecular structure combines a hydrophobic octylphenol group with a hydrophilic polyoxyethylene chain (approximately 21 EO units), endowing the product with excellent surface activity and broad application adaptability.
As a nonionic surfactant, OP-21 does not ionize in solution and exhibits excellent compatibility with anionic, cationic, and amphoteric surfactants. Additionally, it maintains stable surface activity and functionality in acid, alkali, and hard water systems, demonstrating strong chemical tolerance. This enables reliable performance under complex industrial conditions.
OP-21 has high active ingredient content and excellent usage efficiency, helping users reduce formulation addition amounts and lower overall costs. It should be noted that this product is classified as a skin irritant (Category 2) and an eye irritant (Category 2A), and may pose potential hazards to the reproductive system (Category 2). It is also toxic to aquatic life with long-lasting effects. Safety operating procedures must be strictly followed during use.
| Parameter | Value |
|---|---|
| Product Name | OP-21 Octylphenol Ethoxylate |
| Alias | Emulsifier OP-21, Octylphenol Ethoxylate (21), Polyoxyethylene (21) Octylphenyl Ether |
| CAS No. | 9036-19-5 |
| Ionic Type | Nonionic Surfactant |
| Appearance | White to light yellow waxy paste (consistency varies with temperature) |
| pH (1% aqueous solution, 25°C) | 6.0–8.0 |
| Flash Point (Closed Cup) | >150°C |
| Oral LD50 (Rat) | >2000 mg/kg |
| Dermal LD50 (Rabbit) | >2000 mg/kg |
| Fish 96h LC50 | 1–10 mg/L |
| Daphnia 48h EC50 | 1–10 mg/L |
| Algae 72h ErC50 | 1–10 mg/L |
| GHS Classification | Skin Irritation Category 2 / Eye Irritation Category 2A / Reproductive Toxicity Category 2 / Acute and Chronic Aquatic Toxicity Category 2 |
OP-21, with its excellent emulsifying ability and wetting penetration, is widely used in multiple industrial fields:
Safety Protection: Operators must wear protective gloves, protective clothing, goggles, and face shields. In case of skin contact, wash with plenty of water and soap; if it enters the eyes, rinse carefully with water for several minutes, remove contact lenses if present, and continue rinsing. If irritation persists, seek medical attention.
Environmental Disposal: This product is toxic to aquatic life, and the octylphenol group is persistent in the environment and has endocrine-disrupting properties. Do not discharge waste into water bodies; dispose of as hazardous waste according to local/national/international regulations. Spills should be collected promptly.
Storage Requirements: Store in a locked place and keep away from unauthorized personnel. Obtain and read the Safety Data Sheet (SDS) before use to fully understand the product's hazardous characteristics.