Chlorine ion itself is non-toxic, but some chlorine compounds, such as chlorine gas and organochlorine, are toxic to the human body. Chloride ion is an important anion in the body’s extracellular fluid, which can regulate the acid-base balance and osmotic pressure in the body. Chloride ion itself is not toxic, common table salt is a compound of sodium and chloride ions, but chlorine gas, organochlorine and some other chlorine compounds, the human body has a certain degree of toxicity. First of all, chlorine gas is a gas monomer, yellow-green at room temperature and pressure, with a strong irritating odor, is a highly toxic gas. If chlorine gas enters the human body through the respiratory tract, it will react with the water contained in the mucous membrane to produce hypochlorous acid and hydrochloric acid, thus causing damage to the mucous membrane of the upper respiratory tract; Secondly, for organic chlorine, there are chlorine elements in some organic compounds, which can enter the human body from the digestive tract, respiratory tract or skin and cause poisoning, with chlorophenethylene and so on being the most common. Acute poisoning mainly violates the nervous system, can also lead to liver and kidney damage, will cause weakness, headache, dizziness, nausea, vomiting, abdominal pain, muscle tremor, convulsions, cyanosis and other manifestations; severe poisoning will appear epileptic seizures, coma and other symptoms; a large number of inhalation can occur in pulmonary edema, and even death due to respiratory failure or ventricular fibrillation. The symptoms of poisoning should be timely medical treatment, according to the doctor’s advice, to avoid delaying the condition.