Inhibit respiratory enzymes,causing intracellular asphyxia.Inhalation,oral administration,or transdermal absorption can all cause acute poisoning.Oral administration of 50-100mg can cause sudden death.Non sudden death can be clinically divided into four stages:prodromal stage with mucosal irritation,increased and deepened breathing,fatigue,and headache;Oral administration can cause numbness on the tip of the tongue and mouth.During the difficult breathing period,there may be difficulty breathing,elevated blood pressure,and bright red skin and mucous membranes.During the convulsion period,convulsions,coma,and respiratory failure may occur.During the paralysis period,the muscles of the whole body relax,breathing and heartbeat stop,and death occurs.Long term exposure to small amounts of cyanide can lead to neurasthenia syndrome,eye and upper respiratory tract irritation.May cause rash.

　　Emergency measures

　　Skin contact:Immediately remove contaminated clothing and thoroughly rinse with running water or 5%sodium thiosulfate solution for at least 20 minutes.Seek medical attention.

　　Eye contact:Immediately lift the eyelids and thoroughly rinse with plenty of flowing water or saline solution for at least 15 minutes.Seek medical attention.

　　Inhalation:Quickly leave the scene and move to a place with fresh air.Keep the respiratory tract unobstructed.If breathing is difficult,administer oxygen.When breathing and heartbeat stop,immediately perform artificial respiration(do not use mouth to mouth)and chest compressions.Inhale isoamyl nitrite and seek medical attention.

　　Ingestion:Drink plenty of warm water and induce vomiting.Wash the stomach with a 1:5000 potassium permanganate or 5%sodium thiosulfate solution.Seek medical attention.