Invasion route: inhalation, ingestion and percutaneous absorption.

Health hazards: irritation to mucous membrane and skin. Poisoning is mainly caused by inhaling its dust or steam, and methemoglobinemia occurs after absorption. Acute poisoning patients have symptoms such as headache, dizziness, fatigue, cyanosis of skin and mucosa, numbness of fingers, etc. In severe cases, chest tightness, dyspnea, palpitation and even arrhythmia, coma, convulsion and respiratory paralysis may occur. Sometimes it can lead to hemolytic anemia and liver damage.

Chronic poisoning has symptoms of neurasthenia syndrome such as headache, fatigue, insomnia and memory loss; When there is chronic hemolysis, jaundice and anemia may occur; It can also cause toxic hepatitis.

Environmental hazard: toxic to aquatic organisms.

Explosion hazard: flammable, and its powder can form explosive mixture when mixed with air.