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To address the knowledge question, everyone should learn a bit about p-toluidine. (1) Overview of hazards Hazard category: Class 6.1 – Toxic substances Routes of exposure: Inhalation, ingestion, dermal absorption Health hazards: This substance is a strong methemoglobin former; it can irritate the bladder and urethra, leading to hematuria. Acute poisoning is mostly caused by absorption through skin contamination. There is a sensation of burning in the face, severe headache, dizziness, difficulty breathing, and cyanosis. In the future, hematuria, anuria, mental disorders, and muscle spasms may occur. Chronic poisoning can cause bladder irritation symptoms. Environmental hazard: Toxic to aquatic life. Fire and explosion hazard: It is flammable; its powder, when mixed with air, can form an explosive mixture. (II) First aid measures Skin contact: Immediately remove the contaminated clothing and thoroughly wash the skin with soapy water and clean water. Seek medical attention if you feel unwell. Eye contact: Lift the eyelids and rinse with flowing water or saline. Seek medical attention if you feel unwell. Inhalation: Quickly leave the area and go to a place with fresh air. Keep the airway clear. If there is difficulty breathing, administer oxygen. Respiration and heartbeat stopped; CPR was performed immediately. Seek medical attention. Ingestion: Drink plenty of warm water and induce vomiting. Seek medical attention. (III) Fire-fighting measures Hazardous characteristics: Flammable in the presence of open flames or high temperatures. Releases toxic gases upon high-temperature decomposition. Harmful combustion products: carbon monoxide, nitrogen oxides. Fire extinguishing methods: Use fogged water, foam, dry powder, carbon dioxide, and sand to extinguish the fire. Precautions and measures for extinguishing fires: Firefighters must wear air respirators and full-body fire- and poison-resistant suits, and extinguish the fire from the upwind side. Move the container away from the fire as far as possible to an open area. **Keep the containers at the fire site cooled down until the fire is extinguished. If a container in a fire has changed color or sounds are coming from its safety pressure relief device, it must be evacuated immediately. (IV) Emergency response to leaks Emergency actions: Isolate the area contaminated by the leak and restrict access. Eliminate all ignition sources. It is recommended that emergency responders wear dust masks and protective suits. It is strictly prohibited to come into contact with broken containers and leaks before wearing appropriate protective clothing. Seal the source of the leak as much as possible. Cover the spill with plastic sheeting to prevent it from spreading. Do not allow water to enter the packaging container. Use a clean shovel to collect the spill and place it in a clean, dry container with a loosely fitting lid, then move the container away from the spill area. (5) Handling, Disposal, and Storage Handling precautions: Perform operations in a sealed environment and provide adequate local exhaust ventilation. Operators must receive specialized training and strictly adhere to the operating procedures. It is recommended that operators wear hooded electric-powered air-supplied filtering respirators, rubberized gas-proof suits, and rubber gloves. Stay away from sources of fire and heat; smoking is strictly prohibited in the workplace. Use explosion-proof ventilation systems and equipment. Avoid generating dust. Avoid contact with oxidizers and acids. Handle with care during transportation to prevent damage to the packaging and containers. Equipped with appropriate types and quantities of fire-fighting equipment and emergency response devices for leaks. Empty containers may retain harmful substances. Storage precautions: Store in a cool, well-ventilated warehouse. Keep away from flames and heat sources. The packaging must be sealed to prevent contact with air. It should be stored separately from oxidizers, acids, and food chemicals; mixed storage is strictly prohibited. Equip with appropriate types and quantities of fire-fighting equipment. The storage area should be equipped with suitable materials to contain leaks. (VI) Exposure control/individual protection Exposure limits: MAC (mg/m3): No standard established. PC-TWA (mg/m3): No standard established. PC-STEL (mg/m3): No standard established. TLV-C (mg/m3): – TLV-TWA (mg/m3): 2 ppm. TLV-STEL (mg/m3): Monitoring methods: No data available. Engineering controls: Ensure strict sealing and provide adequate local exhaust ventilation. Provide safety showers and eye wash stations. Respiratory protection: Wear a filtered dust respirator when there is a possibility of exposure to its dust. An air respirator should be worn during emergency rescue or evacuation. Eye protection: Wear chemical safety goggles. Body protection: Wear a sealed gas mask. Hand protection: Wear rubber gloves. Other protections: Smoking, eating, and drinking are prohibited at the work site. Change work clothes promptly. Do not drink alcohol before or after work, and take baths with warm water. Conduct pre-employment and regular health checks. O60。 (7) Physical and chemical properties: Appearance and characteristics: The pure substance appears as colorless flaky crystals. pH value: Meaningless Melting point (°C): 44.5 Boiling point (°C): 200.4 Relative density (water=1): 1.05 Relative vapor density (air=1): 3.90 Saturated vapor pressure (kPa): 0.0346 (25°C) Heat of combustion (kJ/mol): 4006.1 Critical pressure (MPa): No data Available Octanol/water partition coefficient: No data Available Flash point (°C): 88.89 Ignition temperature (°C): 481.67 Lower explosive limit: 1.1 Upper explosive limit: 6.6 Solubility: Slightly soluble in water; soluble in ethanol, ether, benzene, and hydrochloric acid. Primary uses: Used as an intermediate for dyes and as an intermediate for the pharmaceutical drug pyrimethamine. (8) Stability and Reactivity Stability: Stable Incompatible substances: Strong oxidizing agents, acids, acyl chlorides, anhydrides, chloroform. Condition to avoid contact: light. Polymerization hazard: Does not polymerize. Decomposition products: Nitrogen oxides. (IX) Toxicological data Acute toxicity: LD50: Oral LD50 in rats (mg/kg): 336; Oral LD50 in mice (mg/kg): 330. Oral LD50 in rabbits (mg/kg): 270; Dermal LD50 in rabbits (mg/kg): 890. LC50: Inhalation LC50 in rats (mg/m3): >640 mg/m3/1H. Irritation: Dermal exposure in rabbits: 500 mg/24 hours, severe irritation; Eye exposure in rabbits: 20 mg/24 hours, moderate irritation. Mutagenicity: DNA inhibition: 200 mg/kg orally in mice. DNA damage: 35 mg/kg intraperitoneally in mice. Off-program DNA synthesis: rat liver 100 umol/L. Carcinogenicity: American Conference of Industrial Hygienists (ACGIH): Animal carcinogen. (10) Waste Disposal Nature of waste: Hazardous waste Method of waste disposal: Disposed of through controlled incineration. The nitrogen oxides emitted from the incinerator are removed through a scrubber. Disposal precautions: Refer to ** and local relevant regulations before disposal. (11) Transport information Hazardous goods code: 61750 UN number: 3451 Packaging category: Class II packaging Packaging mark: Toxic substance Packaging method: Steel drum with small opening ； Ordinary wooden box outside threaded-mouth glass bottles, iron-lid pressed-mouth glass bottles, plastic bottles, or metal drums/tanks ； Glass bottles with threaded mouths, plastic bottles, or tin-plated thin steel sheet drums (tanks), enclosed in grid-bottomed boxes, fiberboard boxes, or plywood boxes. Transportation precautions: Before shipping, check whether the packaging containers are intact and properly sealed. During transportation, ensure that the containers do not leak, collapse, fall, or get damaged. Mixing with acids, oxidizers, foods, and food additives is strictly prohibited. During transportation, it should be protected from exposure to sunlight and rain, as well as high temperatures. CAS No.: 106-49-0 1. Properties: Appearance: colorless, shiny flaky crystals Purity: ≥99% Melting point: 43-45°C Boiling point: 200-202°C 2. Uses: dyes and pharmaceutical intermediates. 3. Packaging and storage: packaged in galvanized drums of 200kg or 220kg weight; store in a cool, dry place. Last edited by hw197358 on 2009-3-1 19:21]