Office Chair Explosion

The term 'office chair explosion' typically refers to the sudden burst of a pneumatic lift-type swivel chair caused by component defects, often due to low-quality gas cylinders, and requires serious attention for prevention.

Causes of Explosion

1. Structural Defects in Gas Cylinders:

   • Thin walls of the gas cylinder rod are a core hazard. To reduce costs, inferior products use low-strength steel, resulting in insufficient wall thickness that cannot withstand repeated impacts from high-pressure gas (usually nitrogen) inside. Over time, this can lead to rupture.
   • Insufficient purity of inert gas or substitution with compressed air. A proper gas cylinder should be filled with high-purity nitrogen (chemically stable), but inferior products may mix in air or use compressed air directly. Oxygen in the air accelerates metal oxidation at high temperatures, reducing wall strength, while compressed air is more affected by temperature changes, leading to sudden pressure variations.
   • Frequent lifting and lowering causing rapid temperature increases. Gas cylinders achieve height adjustment through gas compression. During rapid adjustments, internal gas friction generates heat. If the wall material is not heat-resistant, it may rupture due to thermal expansion and contraction.

2. Lack of Safety Devices:
   The explosion-proof steel plate is a crucial protective component that should be installed between the seat cushion and the gas cylinder rod, with a thickness of at least 2 millimeters. Its role is to block fragments flying out during a gas cylinder explosion, but inferior products often omit this device, causing fragments to directly pierce the human body or damage surrounding objects after an explosion.

Typical Cases

• 2007, Zhoushan, Zhejiang: An office chair exploded, injuring the user.
• 2009, Jiaozhou, Shandong: A 14-year-old boy was killed when the lifting rod of a pneumatic chair pierced his body during adjustment.
• 2013, Xiamen, Fujian: Ms. Liu was pierced in the lower body by explosion fragments.
• 2017, Anhui: An office chair explosion damaged a computer case.
• 2020, A spot check by the State Administration for Market Regulation revealed a 23.3% failure rate in office chairs, with 17 batches being swivel chairs. The main issues were substandard high/low-temperature resistance of gas cylinders and lack of explosion-proof steel plates.

Preventive Measures

1. Choose reputable products: Prioritize well-known brands and consider prices above 200 yuan (lower-priced products are more likely to use inferior components).
2. Check gas cylinder quality:
   • Observe whether lifting and lowering are smooth, without stuttering or abnormal noises.
   • Confirm that the bottom of the gas cylinder has manufacturer and specification labels to avoid using 'three-no' products (no brand, no standard, no label).
3. Verify explosion-proof steel plate: Press the edge of the seat cushion with your hand. If you feel a hard metal plate (thickness ≥ 2 mm) underneath, it indicates the presence of an explosion-proof device.
4. Avoid frequent lifting and lowering: Reduce rapid adjustments to minimize temperature changes inside the gas cylinder.