© 2026 Sinochem Nanjing Corporation,
All Right Reserved
Chemical Name: 4-Methylquinoline
Synonyms: Quinaldine
CAS Number: 91-63-4
Molecular Formula: C10H9N
Appearance: Pale yellow to brown oily liquid with a pungent, unpleasant odor
Common Uses: Starting point for making dyes and pharmaceuticals, sometimes found in pesticides and industrial chemicals.
Physical Hazards: Flammable, has a low flash point and vapor can catch fire if near open flames or hot surfaces.
Health Hazards: Irritates the eyes, skin, and airway. Exposure might leave you with headaches, dizziness, or nausea. Swallowing or breathing high concentrations brings on more serious symptoms. Long-term effects or carcinogenic risks remain up for discussion due to limited human data, though rodents have shown some chronic effects.
Environmental Hazards: Not the friendliest compound for aquatic life; spills or run-off pollute waterways and linger in the soil.
4-Methylquinoline: Pure undiluted compound, about 99% content in most laboratory containers. Impurities usually fall below 1%, but any trace contaminants can matter in sensitive research or manufacturing settings.
Inhalation: Get to fresh air quickly if you've inhaled fumes. Mild symptoms usually clear up, but if breathing gets tough or you feel dizzy, medical attention is necessary.
Skin Contact: Flush with plenty of water for at least 15 minutes. Wash thoroughly with soap and water, remove contaminated clothing.
Eye Contact: Rinse gently and thoroughly with clean water for several minutes, holding eyelids apart. Persistent irritation means you need to get checked.
Ingestion: Rinsing the mouth helps, but seeking medical help trumps everything, especially if larger quantities get swallowed. Do not induce vomiting unless medical personnel tell you.
Suitable Extinguishers: Use dry chemical powder, foam, or carbon dioxide. Water might not be effective, though it can cool fire-exposed containers.
Special Hazards: Burning releases toxic fumes such as nitrogen oxides and carbon monoxide. Vapors travel and flash back, so keep ignition sources far away.
Protective Equipment: Firefighters need full protective gear and a self-contained breathing apparatus. Even trained workers shouldn’t take chances without gear, as toxic gases expand quickly during fire.
Personal Precautions: Make sure you’re wearing gloves, goggles, and a respirator if dealing with a large spill. Ventilate the area well, since vapors build up easily.
Environmental Precautions: Keep chemical from running into surface water or drains. Large spills in the field or in labs should get professional attention immediately.
Containment and Cleanup: Small spills soak up best with absorbent, non-combustible material; use sand or industrial absorbent. Gather waste into a suitable container for later disposal.
Handling: Keep a close lid on storage containers—vapors seep out and build up quickly. Don’t eat, drink, or smoke while handling. Avoid breathing mist or vapor, always wash hands after use.
Storage: Use tightly closed containers. Cool, dry, and well-ventilated storage makes a big difference for stability. Flammable chemical cabinets with good labeling keep accidents from spiraling.
Engineering Controls: Use chemical fume hoods where possible. Proper ventilation keeps airborne concentrations down.
Personal Protection: Wear splash goggles or a face shield. Gloves made of nitrile or neoprene offer good resistance. Long sleeves and lab coats protect exposed skin. Respirators come into play when exposure goes over safe limits or during cleanup of spills.
Exposure Limits: Regulatory data is thin, and exposure limits may not exist for every region. Reasonable practice means treating this as a hazardous substance.
Appearance: Pale yellow oily liquid
Odor: Sharp, pungent, and sometimes downright unpleasant
Boiling Point: 244°C
Melting Point: -15°C
Flash Point: 94°C (closed cup)
Solubility: Limited in water; soluble in most organic solvents
Vapor Pressure: Low at room temperature, but builds up in warm and closed spaces
Density: About 1.03 g/cm³
Chemical Stability: Stays stable at normal room temperature and recommended storage conditions.
Reactivity: Will not react suddenly under standard use, but mixes badly with strong oxidizers or acids—fire and toxic fumes can result.
Hazardous Decomposition: Heating or burning breaks it down into nitrogen oxides, carbon monoxide, and sometimes ammonia.
Routes of Exposure: Breathing in vapors, skin contact, eye contact, ingestion
Acute Effects: Skin burns, headaches, nausea. Prolonged contact worsens irritation.
Chronic Effects: Not much firm data for humans, but animal studies hint at possible liver and kidney impact after repeated exposure. Effects on reproduction or cancer risk have been seen in closely-related chemicals but have not been established for certain here.
Aquatic Toxicity: Toxic to fish and aquatic invertebrates. Even small releases can disrupt aquatic systems.
Persistence and Degradability: Doesn’t break down quickly. Tends to hang in sediments and soils if not actively cleaned.
Bioaccumulation: The molecule can build up in aquatic organisms over time, creating knock-on effects for the wider food chain.
Disposal Methods: Treat as chemical waste—never pour down the drain. Professional hazardous waste disposal companies can process the compound according to local or national regulations.
Container Handling: Empty containers hold residue; rinse them thoroughly, then send for managed disposal.
Proper Shipping Name: 4-Methylquinoline, regulated as a hazardous chemical
Hazard Class: Flammable liquid
Transport Precautions: Keep containers upright and tightly sealed. Vehicles should carry emergency cleanup gear just in case of a highway accident or leakage during shipment.
Lab and Industrial Use: Many countries restrict use under workplace chemical safety standards like OSHA, REACH, or similar.
Environmental Restrictions: Discharge is regulated—pollution or improper waste management brings steep penalties.
Labeling: Warning labels required for storage and transport. Users handle the chemical as a hazardous substance in all regulatory contexts where there's a risk for fire or environmental damage.
