Accident details

On February 22, 2025, a poisoning and suffocation accident occurred in the factory area of Henan Yi Biotechnology Co., Ltd., resulting in 2 deaths and 2 injuries.

During the dismantling of the pipeline from the reaction system of the thiocarbazide production unit to the centrifugal system, three staff members were poisoned due to the release of residual hydrogen sulfide from the reaction kettle. The other two staff members failed to take effective protective measures and blindly rescued, resulting in the escalation of the consequences of this accident.

Hydrogen sulfide: a hidden 'lightning killer'

Hydrogen sulfide is a colorless, flammable, and toxic gas with a strong odor of rotten eggs. It is easily soluble in water, has a density greater than air, and is prone to accumulate in low-lying, enclosed spaces. Moreover, hydrogen sulfide is a strong neurotoxin with extremely prominent hazardous characteristics. The harm to the human body is mainly reflected in the following aspects:

Low concentration exposure: • Irritates the eyes and respiratory tract, causing symptoms such as cough, headache, and heartburn.

Moderate concentration exposure: • Causes difficulty breathing, pulmonary edema, and in severe cases, may lead to coma.

High concentration exposure: Long term exposure may cause long-lasting damage to the nervous system.

⚠️ Special Reminder:

Olfactory fatigue: After prolonged exposure to low concentrations of hydrogen sulfide, one may not be able to smell the odor and mistakenly believe it is safe!

High concentration lethal: Inhaling high concentration hydrogen sulfide can lead to "electrocution like" death, without even a chance to call for help!

How to prevent hydrogen sulfide poisoning?

Enterprise safety production measures

1. Install detection alarms: Install gas detectors in areas prone to hydrogen sulfide production.

2. Forced ventilation: Ensure proper ventilation of the space before starting work to prevent gas accumulation.

3. Wear protective equipment: When entering hazardous areas, it is necessary to wear a gas mask or air respirator.

4. Safety training: Employees should master the characteristics of hydrogen sulfide, emergency response, and cardiopulmonary resuscitation skills.

Hydrogen sulfide safety operation plan

Before homework: Energy isolation (such as adding blind plates) and bottom cleaning replacement must be performed, and gas detection must be carried out to confirm safety.

During homework: Personnel must wear suitable portable detectors and positive pressure air respirators, and the use of filter type gas masks is strictly prohibited. Outdoor operations should be equipped with wind indicators, and personnel should be located in the upwind direction.

In case of emergency: Once the alarm goes off, the emergency plan must be activated immediately. The primary principle is: Without professional protection, rescue is strictly prohibited! Rescue personnel must wear air respirators and quickly move the poisoned person to a place with fresh air; If breathing stops, immediate cardiopulmonary resuscitation should be performed (avoiding mouth to mouth resuscitation to prevent poisoning of rescuers), and emergency medical attention should be sought.

Source: Puyang Emergency Management Bureau and Network. Copyright belongs to the original author. If there is any infringement, please contact us