According to the official WeChat account of "Guangdong Emergency Management" on May 4, at 4: 00 p.m. on May 1, 2021, Xinli Semiconductor Co., Ltd., located in Shanwei City, had a suffocation accident in a limited space during the cleaning of the O water tank, resulting in the suffocation and death of four operators of the outsourcing unit working in the water tank.

On the morning of May 1, four operators of Shanwei Jingxin Technology Co., Ltd. left the water room after completing the replacement of PVC water pipe joints and maintenance of the water tank. At about 2: 15 p.m., four other operators entered the water room one after another to clean the water tank. At 4:20, the person in charge of the equipment department of the factory found that four operators were lying on the water at the bottom of the water tank (about 50 cm deep) and died after rescue.

The following are the causes of the accident investigated:

Before entering the water tank for operation, the four operators failed to meet the requirement of "ventilation first, testing later, and then operation" in the safety management of limited space operation, and ventured into the water tank with insufficient oxygen content (the oxygen content detected during rescue was 7.5) to suffocate and die.

A confined space job is also referred to as a confined space job and a confined space job. Regarding restricted space, the national standard has a clear definition, which refers to the limited space that is relatively isolated from the outside world, restricted in import and export, poor natural ventilation, and only enough for one person to enter the limited space that is engaged in unconventional and continuous operations, such as furnaces, towers, Wells, tanks, etc.

There are many dangerous and harmful factors in limited space or confined space, such as: there may be toxic and harmful media and combustible gases, which may belong to anoxic environment.

Among them, the hypoxia environment is extremely harmful to the human body. Low oxygen concentration can cause human hypoxia, common symptoms are dizziness, drowsiness, listlessness, anger, irritability and so on. Long-term hypoxia can lead to low blood oxygen levels, and the cerebral cortex is first directly damaged by zui. If the brain gets sick first, the damage to the human body will be obvious, and a series of serious consequences such as cardiac arrest, myocardial failure, and blood circulation failure will occur.

And in a closed space, the amount of carbon dioxide produced as humans breathe will gradually increase. Although carbon dioxide itself is non-toxic, when its concentration in the surrounding air is large, the proportion of oxygen is relatively reduced, and the human body does not have enough oxygen proportion to enter the body when breathing, resulting in hypoxia and death.

Therefore, in the limited space operation, it is necessary to monitor the oxygen concentration in the environment, the concentration in the normal range can start the operation, and the operation project should maintain good ventilation. The element commonly used to detect oxygen concentration is an oxygen sensor,Fluorometric oxygen sensors can LuminOx-LOX-02 be used for oxygen concentration detection.

Fluorescence oxygen sensor LuminOx-LOX-02 advantages:

Replaceable electrochemical sensor, small size, low power consumption, meeting RoHS standards, long life (greater than 5 years) and fully built-in environmental compensation;
Suitable for medical treatment, baby incubator, inerting and other fields;
Range 0-25%(O2%) or 0-300mbar(ppO2);
High accuracy: 2% FS;
Response time: Working voltage: 4.75-5.25V (recommend 5v) Average current: Output signal: RS232 TTL level.