4-Nitroaniline, known by its chemical formula C6H6N2O2, belongs to the class of aromatic amines. It forms from aniline through nitration, producing a yellow crystalline solid with a characteristic odor. As someone with years of laboratory experience, the clear, sharp color shift is one of the most recognizable features in handling this substance. The molecular weight stands at 138.13 g/mol, and the compound presents a density of about 1.44 g/cm³. The HS Code for standard trade purposes is 29214200, classing it as an aromatic nitro compound. Handling the raw materials leading to 4-Nitroaniline requires attention to safe storage and transport, not only due to its hazardous properties, but also the tendency for powdered or crystalline forms to produce dust that lingers in the air.
Physical form matters, particularly for chemical processing or synthesis. 4-Nitroaniline typically appears as pale yellow flakes or crystalline powder, though some production lines push for tiny pearls or compressed solid plates for shipping stability. It resists dissolving in water, but organic solvents like ethanol and ether make quick work of it, breaking it down for use in solution-based applications. The melting point clocks in around 146°C, a practical range for both laboratory and bulk manufacturing environments. Its structure shows a benzene ring with para-substituted nitro and amine groups, which creates a strong electron push-pull system—a detail that influences its role in dyes and pigments. Dealing with it in crystal form, I've had to respect the dust and the distinct smell, both signs that ventilation and proper containment are not up for debate.
PNA stands out in the chemical world for its dual nature: the nitro group pushes electrons, the amine group pulls them back, which makes this compound valuable for intermediates in dyes, pigments, and some pharmaceutical products. Laboratories and industrial plants favor PNA for making azo dyes and for use as a chemical raw material. Speaking from the floor, the solid and powder forms are easiest to measure and store, but the pearl and flake forms reduce dust generation. This comes as no small matter, because exposure without protection can impact the blood, liver, or kidneys. Strong safety routines with gloves, masks, and precise ventilation become non-negotiable. Hazards show up not just in the raw material itself, but in its breakdown—nitro compounds release toxic fumes if overheated or involved in an accident during storage or transport.
Standards for 4-Nitroaniline often specify purity above 99%, moisture content below 0.5%, and tightly controlled impurity profiles. Producers regularly trace batches using batch number, lot number, and HS Code. The density sits around 1.44 g/cm³ for the crystalline solid, a detail that feeds directly into weight-based dosing in industrial setups. I've encountered strict audit conditions around labeling, especially because regulators want to see clear “hazardous material” warnings for any volume over a kilogram. Even field technicians know to look for compatibility charts, because storing 4-Nitroaniline next to incompatible chemicals can trigger dangerous side reactions. The focus on transparent, accurate specification directly ties into workplace safety and environmental stewardship.
Safety dominates every conversation about 4-Nitroaniline. It brings health hazards if inhaled or if skin contact lasts too long. Symptoms can include methemoglobinemia, which impacts the blood's ability to carry oxygen. I keep spill kits and activated charcoal on hand when preparing or transferring large volumes. Strong guidelines urge storing PNA in dry, cool, and ventilated facilities—far from any ignition source and in the right kind of chemical-resistant containers. Material safety data sheets recommend goggles and lab coats for any handling outside of a full enclosure system. Accountability for waste disposal goes up, since 4-Nitroaniline and its solutions must never mix with standard drains or municipal sewers. My experience echoes the consensus: keeping this chemical safe means attention to detail and zero shortcuts.
4-Nitroaniline’s importance tracks through manufacturing, textile, and research corridors, where its unique electron-sharing structure opens doors to more vibrant, durable products. Meeting demand means keeping the supply chain secure, prices stable, and manufacturing impacts minimal. Improvements target safer production, less waste, and lower emissions. Some researchers chase alternatives to lower the toxic load. From loading dock to fume hood, every step demands skilled hands and a watchful eye—practical safety culture keeps operations running and communities safe, while innovation looks toward a future where industry benefit and public health walk the same line.
