4-aminobenzenesulfonic acid

4-aminobenzenesulfonic acid is an aromatic organic compound with the molecular formula C6H7NO3S and CAS number 121-57-3. This chemical features both an amino group (-NH2) and a sulfonic acid group (-SO3H) attached to a benzene ring, making it an aminosulfonic acid derivative. With a molecular weight of 173.19 g/mol, it serves as an important intermediate in chemical synthesis and industrial applications.

4-aminobenzenesulfonic acid typically appears as a white to off-white crystalline solid at room temperature. The compound is highly soluble in water due to its sulfonic acid group, which makes it polar and ionic in nature. It has good thermal stability under normal conditions and exhibits typical aromatic compound characteristics. The presence of both amino and sulfonic acid functional groups gives it amphoteric properties.

4-aminobenzenesulfonic acid serves primarily as an intermediate in the synthesis of dyes, pigments, and pharmaceutical compounds. It is commonly used in the production of azo dyes and as a building block for various organic syntheses. The compound finds applications in the textile industry, chemical manufacturing, and research laboratories. Its dual functional groups make it valuable for creating complex molecular structures in fine chemical production.

4-aminobenzenesulfonic acid requires careful handling as it can cause skin and eye irritation and may cause skin sensitization. Always wear appropriate personal protective equipment including safety goggles, chemical-resistant gloves, and protective clothing. Work in well-ventilated areas or use local exhaust ventilation to minimize exposure. Avoid direct contact with skin and eyes, and prevent inhalation of dust or vapors during handling operations.

4-aminobenzenesulfonic acid should be stored in a cool, dry, well-ventilated area away from direct sunlight and heat sources. Keep containers tightly closed when not in use to prevent moisture absorption and contamination. Store away from strong oxidizing agents and incompatible materials. Ensure proper labeling and maintain storage temperatures within recommended ranges to preserve product quality and prevent degradation.

Immediate action is required upon contact with 4-aminobenzenesulfonic acid. For skin contact, remove contaminated clothing and rinse affected area thoroughly with plenty of water for at least 15 minutes. For eye contact, flush immediately with clean water for 15-20 minutes while holding eyelids open. If irritation persists or if inhaled, seek medical attention promptly. Remove person to fresh air if respiratory irritation occurs.

4-aminobenzenesulfonic acid disposal must comply with local, national, and EU waste regulations. The compound should be treated as hazardous chemical waste and disposed of through licensed waste management companies. Do not discharge into drains, water courses, or onto the ground. Small quantities may be neutralized under controlled conditions before disposal, but always consult local environmental authorities for specific disposal requirements and approved methods.

4-aminobenzenesulfonic acid is not classified under ADR dangerous goods regulations for transport, simplifying its shipping requirements. However, proper packaging is still essential to prevent spillage and contamination during transit. Use appropriate containers with secure closures and clear labeling indicating the chemical name and hazard warnings. Follow general chemical transportation guidelines and ensure compliance with carrier-specific requirements for chemical shipments.

4-aminobenzenesulfonic acid is subject to standard EU chemical regulations including REACH and CLP classification requirements. It is classified as Skin Irritant Category 2, Eye Irritant Category 2, and Skin Sensitizer Category 1, requiring appropriate hazard labeling with GHS07 pictogram and 'Warning' signal word. The substance is not listed as SVHC under REACH, but standard registration and safety data sheet requirements apply for commercial use.

4-aminobenzenesulfonic acid is available through OYSI, a trusted European distributor of specialty chemicals and industrial raw materials. OYSI provides high-quality chemical products with proper documentation, safety data sheets, and regulatory compliance support throughout Europe. Contact OYSI directly to inquire about availability, packaging options, and delivery to your location. Professional technical support is available to assist with product specifications and applications.