Nitrogen poisoning, where is the gas mask?

A mechanical and electrical equipment engineering company did not wear a gas mask and did not follow the rules when performing maintenance work in the metering tank area of ​​the workshop, resulting in a nitrogen suffocation accident, resulting in one death and two injuries.
First, the accident process

As early as before the accident, the petrochemical plant began to stop and overhaul. In the morning, the construction of the replacement project of propylene oxide metering tank coils was completed. Subsequently, the petrochemical plant fills the nitrogen in the propylene oxide metering tank and conducts the hydrostatic pressure test according to the process requirements. During the hydrostatic pressure test, the short section has leak points. At the maintenance meeting held around 16:30 pm, the workshop decided to replace the short section and Zhou and Hao were responsible for arranging the implementation. Around 17:30, Zhou and Hao informed Liu that the replacement of a short section of flange in the metering tank was required. Master Liu instructed the employee to open the manhole cover of the propylene oxide metering tank when he had not gone through the “Entry of Constrained Space Operations Permit”. At that time, the worker did not take corresponding safety measures and entered the tank through the manhole to cause asphyxia. Another 2 During the rescue process, people were poisoned and suffocated. One of the masters died after being rescued.

Second, the cause of the accident

Master Liu did not take appropriate safety measures. He died of suffocation through the manhole and was the direct cause of the accident.

There is a lack of unified coordination and management of the safety production work of maintenance contractors; safety assessment companies do not analyze the hazardous and hazardous factors of nitrogen in the production and maintenance processes and propose safety precautions in the company’s safety assessment report, and are also the main cause of accidents. .

Nitrogen is a colorless, odorless and tasteless gas at normal temperature and pressure, and it can be liquid after being pressurized. When the nitrogen content in the air increases, people feel uncomfortable to breathe and feel suffocated. High concentrations of nitrogen can cause simple asphyxia, manifested as headache, nausea, vomiting, chest tightness, chest pain, numbness of the extremities, increased muscle tone, paroxysmal spasm, purpura, miosis, weakened light response, and other crisis symptoms Serious people quickly become unconscious and even die.

Third, preventive measures

The relevant safety production departments should strengthen management, improve various systems, and strictly handle violations of rules and regulations, and never be weak.

Strengthen education and training for the safety of employees, and related work must wear protective equipment such as gas masks.

For operating factories, on-site management must be strengthened to ensure the safety of workers' lives.