In the realm of chemical manufacturing and research, a thorough understanding of the properties and safe handling of raw materials is fundamental. 4-Nitrophenol, identified by its CAS number 100-02-7, is a significant organic compound with diverse industrial applications, most notably as an intermediate in agrochemical synthesis and as a pH indicator. For procurement specialists, R&D scientists, and EHS managers, a detailed grasp of its characteristics is essential for efficient sourcing and safe operational practices.

Physical and Chemical Properties

4-Nitrophenol typically appears as yellow to brown crystals. Its physical state is solid at room temperature, with a melting point generally reported around 112-114 °C. The compound is moderately soluble in water, with solubility increasing with temperature, and is soluble in common organic solvents like ethanol. Its molecular formula is C6H5NO3, and its molecular weight is approximately 139.11 g/mol.

Chemically, 4-Nitrophenol is a phenolic compound bearing a nitro group. As a weak acid, it exhibits a pKa of approximately 7.15 at 25 °C, which underpins its function as a pH indicator. Its boiling point is around 279 °C at standard atmospheric pressure, though decomposition may occur at elevated temperatures. The flash point is approximately 169 °C, indicating it is combustible but requires significant heat to ignite.

Key Applications

The primary industrial significance of 4-Nitrophenol lies in its role as a precursor for synthesizing advanced agrochemicals. It is a vital intermediate in the production of insecticides such as Triflumuron and Hexaflumuron, which are critical for modern pest management in agriculture. Its ability to change color from colorless to yellow over a pH range of 5.4-7.5 also makes it a useful pH indicator in laboratory and industrial settings for qualitative analysis and process monitoring.

Safety and Handling Guidelines

Like many industrial chemicals, 4-Nitrophenol requires careful handling to ensure safety. It is classified as harmful if swallowed, inhaled, or comes into contact with skin. Prolonged or repeated exposure may cause damage to organs. Consequently, appropriate personal protective equipment (PPE) is essential:

  • Respiratory Protection: Avoid breathing dust. Use in a well-ventilated area or with appropriate respiratory protection.
  • Skin and Eye Protection: Wear chemical-resistant gloves, protective clothing, and eye protection (safety glasses or goggles).
  • Ingestion Prevention: Do not eat, drink, or smoke when handling the substance.

Storage recommendations typically include keeping the compound in a cool, ventilated place, away from incompatible materials. For businesses looking to purchase 4-Nitrophenol, it is imperative to obtain and review the Material Safety Data Sheet (MSDS) provided by the supplier. This document offers comprehensive information on hazards, first-aid measures, fire-fighting procedures, and accidental release measures.

By understanding these properties and adhering to safety protocols, industrial users can confidently and safely incorporate 4-Nitrophenol into their production processes. Sourcing from reputable manufacturers who provide clear documentation and product specifications is a key step in ensuring both operational safety and product quality.