Maleic anhydride is classified as a Class 8 corrosive substance among hazardous chemicals and is highly toxic. Operators must undergo specialized training and strictly adhere to operating procedures. Maleic anhydride poses significant harm to the human body, irritating the skin and mucous membranes. When exposed to its high-temperature liquid, the irritation becomes more severe, causing skin burns, redness and swelling of the conjunctiva and cornea, and in severe cases, leading to vision impairment or even blindness. Its dust and vapor are highly irritating, and accidental inhalation can cause burns, pharyngitis, laryngitis, bronchitis, or even pulmonary edema.

Maleic anhydride is highly corrosive. If it comes into contact with the skin, immediately remove contaminated clothing and rinse thoroughly with plenty of running water for at least 15 minutes. Seek medical attention promptly.
If it comes into contact with the eyes, immediately lift the eyelids and rinse thoroughly with plenty of running water or saline solution for at least 15 minutes. Seek medical attention promptly. If accidentally inhaled, quickly move to an area with fresh air. Keep the respiratory tract clear. If breathing difficulties occur, administer oxygen immediately. If breathing stops, perform artificial respiration and seek medical attention immediately. If accidentally ingested, rinse the mouth with water immediately, drink plenty of milk or egg whites, and seek medical attention promptly.