Office Chair Explosion

Office chair explosion mainly refers to the sudden explosive phenomenon of pneumatic lifting swivel chairs caused by component defects, which mostly occurs in low-quality pneumatic rod products.

Explosion Principle

Pneumatic rods are essentially miniature high-pressure vessels. Legitimate products are filled with inert nitrogen gas, which can withstand thousands of kilograms of pressure. However, if unscrupulous manufacturers replace it with compressed air, the oxygen in the air will erode the inner metal walls, making the steel brittle. The heat generated by daily lifting and lowering friction will increase the internal pressure. When exposed to summer sun, sudden sitting, or internal tiny cracks, an explosion may occur.

Typical Cases

Several similar tragedies have occurred in China. In 2013, Ms. Liu in Fujian Province was sitting on a swivel chair blow-drying her hair when the chair exploded without warning. A steel tube about two centimeters in diameter shot out, piercing her lower body. Fragments of various shapes were removed from her abdomen, with several pieces of metal debris remaining in her intestines alone. In 2009, a 14-year-old boy in Jiaozhou, Shandong, died after a top rod from a pneumatic chair pierced his body while adjusting it.

Inspection Findings

According to a spot check by the State Administration for Market Regulation, the failure rate of office chairs reached 23.3% in 2020, with 17 batches being swivel chairs. The main issues were the substandard high- and low-temperature resistance of the pneumatic rods and the lack of explosion-proof steel plates.

Causes of Explosion

Thin walls of the pneumatic rod, insufficient purity of the inert gas or its replacement with compressed air, and frequent lifting and lowering leading to a sudden increase in temperature are all significant factors contributing to explosions.

Preventive Measures

• Choose legitimate products: It is recommended to select products from legitimate manufacturers priced above 200 yuan and avoid purchasing low-quality, low-priced products.
• Inspect the pneumatic rod: Ensure that the pneumatic rod lifts and lowers smoothly without any stuttering or abnormal noises.
• Verify the explosion-proof steel plate: Check whether a explosion-proof steel plate with a thickness of at least 2 millimeters is installed between the seat cushion and the pneumatic rod. This is a crucial component to prevent metal fragments from flying during an explosion.