Phosgene poisoning

Introduction to phosgene poisoning Phosgene, also known as phosgene (COCL2), is colorless, has a moldy firewood odor, is rarely soluble in water, and forms hydrochloric acid after hydrolysis. It is prepared from activated carbon from a mixture of carbon monoxide and chlorine. It is more than 3 times heavier than air, and it is non-irritating to the mucous membrane, so that the human body inhaling high-concentration phosgene has no feeling. The main industrial use of phosgene is to produce aniline dyes. Other industries with more exposure opportunities are firefighters and welding workers. basic knowledge The proportion of sickness: 0.00001% Susceptible people: no specific population Mode of infection: non-infectious Complications: pulmonary edema

Cause of phosgene poisoning

Contact raw materials (80%):

Industries with more exposure opportunities are phosgene manufacturing; organic synthesis such as pharmaceuticals, synthetic rubber, foams, dyes, pesticides, etc.; carbon tetrachloride, chloroform or chloropicrin and other aliphatic chlorocarbons can be produced when burned Phosgene, used as a military poison.

Pathogenesis

The phosgene toxicity is 10 times greater than that of chlorine. The carbonyl group in the phosgene molecule combines with the protein and enzyme of the lung tissue to form an acylation reaction, which interferes with the normal metabolism of the cell, damages the cell membrane, damages the alveolar epithelial cells and capillaries, and permeability. Increased, resulting in chemical pneumonia and pulmonary edema.

Phosgene poisoning prevention

Personal protective measures:

1. Skin protection Use insulated gloves and protective clothing.

2. Use a mask for eye protection.

3. Inhalation protection should be applied to closed systems and ventilation, local exhaust or respiratory protection.

Phosgene poisoning is completely avoidable. Because it has moldy hay and rotten fruit flavor, it can serve as an early warning for contacts and help people to prevent it from early detection. But the most fundamental thing to prevent phosgene poisoning is to reform the process, install an automatic control system, automatically adjust the ratio of raw material gas, and reduce the chance of workers coming into contact with phosgene. In the work, the operator should timely deal with the tail gas generated during the production process of phosgene chemical products, avoiding the direct discharge of tail gas and causing poisoning accidents. In normal times, the phosgene production equipment should be regularly repaired to prevent leakage, and the pipeline should be washed with hot steam. In order to evaporate and destroy the liquid phosgene, it can be repaired when there is no phosgene.

Regularly measure the phosgene concentration of the production site. If the phosgene concentration is exceeded, positive measures should be taken to eliminate the phosgene concentration in the production site. In the event of a large amount of phosgene leakage in the production site, it can be eliminated by ammonia spray neutralization. In the event of a phosgene poisoning accident, the ambulance personnel should first wear an oxygen breathing apparatus and other viable gas masks at the ambulance site where the phosgene concentration is high. If the above personal protective measures are not taken, they should not enter the scene to avoid the situation. Further expansion. In the ambulance process, ambulance personnel should also pay attention to cut off the source of poison. After being rescued, the poisoned person should quickly move to the fresh air, remove the contaminated clothes, wash the contaminated skin, keep warm and send it to the hospital for treatment.

For people with mental illness, heart disease, active tuberculosis, bronchial asthma, recurrent chronic bronchitis and emphysema, it is not suitable for phosgene operations. All units that are exposed to phosgene must strengthen their leadership, do a good job in publicity and education on safe production, and hand over anti-drug knowledge to the masses of workers and establish the necessary systems.

Phosgene poisoning complications Complications pulmonary edema

Often with pulmonary edema, if not treated in time, it can develop into respiratory distress syndrome.

Symptoms of phosgene poisoning Common symptoms Breathing nausea, chest tightness, dizziness, shortness of breath, two lungs, full of miliary shadows

There is an incubation period from inhalation of phosgene to pulmonary alveolar edema, usually 6 to 15 hours, and as short as 2 hours or less. The symptoms of respiratory tract irritation are not obvious after phosgene inhalation, and the presence of incubation period is given to early detection and diagnosis. It is difficult to get nausea, dizziness, cough, sternal discomfort, wheezing and shortness of breath, suffocation and blood stasis. The symptoms of children are often not obvious, mainly based on objective performance, such as cough, nausea, vomiting, etc. Mainly subjective discomfort such as chest tightness, shortness of breath, dizziness, fatigue.

Phosphorus poisoning check

X-ray examination: chest X-ray symptoms appear earlier than signs, chest radiographs should be taken immediately after poisoning, 8h, 24h, and compared. If the chest radiograph remains unchanged after 8 hours of poisoning, there is little chance of pulmonary edema. Early changes in pulmonary edema are interstitial pulmonary edema, often in the incubation period without obvious symptoms. Therefore, early interstitial pulmonary edema can be found through chest X-ray, which is extremely important for treatment and prognosis.

Laboratory examination: arterial oxygen partial pressure is lower than the expected value of 1.33 ~ 2.66KPa.

Other auxiliary examinations: X-ray films are necessary for the diagnosis of acute phosgene pulmonary edema.

Phosphorus poisoning diagnosis and identification

X-ray chest radiograph is a necessary method for diagnosing acute phosgene pulmonary edema. The change is earlier than the symptoms and signs. The chest radiograph should be taken immediately after poisoning, 8h, 24h, and the chest radiograph remains unchanged after 8h of poisoning. Pulmonary edema is unlikely, pulmonary edema changes to interstitial pulmonary edema, often in the latent period without obvious symptoms, so early interstitial pulmonary edema can be found through chest radiograph, which is extremely important for treatment and prognosis. significance.

Should be differentiated from cardiogenic pulmonary edema, heart failure.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.