What are the properties of aniline?

Chemical properties of aniline and safety measures for its handling. Aniline, also known as aminobenzene, is the most commonly handled chemical hazard at Yantai Port, with an annual handling volume of up to 37,000 tons. Familiarizing oneself with its chemical properties and implementing appropriate safety measures can greatly ensure operational safety. I. Properties of aniline: The molecular formula of aniline is C6H5NH2; it is a colorless, oily flammable liquid with a distinctive odor. Its density is 1.0235 g/cm3, the melting point is -6.2°C, the boiling point is 184.4°C, the flash point is 70°C, and the auto-ignition temperature is 770°C. It is soluble in water, ethanol, benzene, and various organic solvents; its aqueous solution is alkaline. It is an organic toxic substance, with a UN regulation number of 84162. Store in a cool, well-ventilated, and dry warehouse, away from sources of fire and heat. It should be kept separate from oxidizing agents. This substance has moderate toxicity; inhaling aniline vapor or absorbing it through the skin can cause poisoning. It acts strongly on the central nervous system, leading to symptoms such as dizziness, fatigue, darkening of the lips and nails, and even vomiting. In case of a fire, water, carbon dioxide, sand, or foam can be used to extinguish it. II. Safety measures for aniline loading and unloading operations 1. A restricted area should be designated at the operation site, and regular inspections should be carried out; unauthorized personnel are strictly prohibited from entering the site. Smoking, carrying open flames, and performing open-flame operations are prohibited in the workplace. 2. The workers should be properly dressed and equipped with activated carbon gas masks, gloves, protective goggles, etc. 3. The work site should be monitored by health and epidemic prevention authorities, who should take immediate rescue measures once any cases of poisoning are detected. 4. The work site should be equipped with several push-type dry powder fire extinguishers, hand-held dry powder fire extinguishers and other fire-fighting equipment, as well as a certain amount of sand, spill recovery devices, etc., and should be supervised by fire trucks on site. 5. All flange connections and access openings in the storage tanks must be fitted with PTFE gaskets to prevent leakage, as well as to avoid leaks caused by the rupture of the gaskets due to excessive local pressure. 6. Operators must strictly adhere to operating procedures and labor discipline; it is strictly prohibited to carry out work under the influence of alcohol. 7. The work site should be equipped with a sufficient quantity of emergency self-supplied oxygen respirators, gloves, water shoes, suction bottles, an appropriate amount of sand and other materials needed to handle emergencies. 8. The loading personnel should stand upwind and pay attention to changes in the liquid level inside the tank to prevent overflow. Two to three people should be involved in the loading process simultaneously, wearing anti-static work clothes, filtered respirators, gloves, glasses, and other protective equipment. 9. During the loading process, pay attention to changes in the nitrogen seal pressure inside the storage tank to prevent the tank from developing a negative pressure and collapsing due to an excessive loading rate. 10. The loading pump room must have adequate ventilation; any leaks should be repaired promptly, and open-flame operations or smoking are prohibited in the loading area.

Physical properties Appearance and characteristics: Colorless or slightly yellow oily liquid with a strong odor. 　　Melting point (°C): -6.2 Relative density (water=1): 1.02 Boiling point (°C): 184.4 Relative vapor density (air=1): 3.22 Molecular formula: C6H7N Molecular weight: 93.12 Saturated vapor pressure (kPa): 2.00 (77°C) Heat of combustion (kJ/mol): 3389.8 Critical temperature (°C): 425.6 Critical pressure (MPa): 5.30 Logarithm of octanol/water partition coefficient: 0.94 Flash point (°C): 70 Upper explosive limit (% V/V): 11.0 Lower explosive limit (% V/V): 1.3 Solubility: Slightly soluble in water; soluble in ethanol, ether, and benzene.