Explosion of Office Chairs Due to Height Adjustment

The explosion of office chairs due to height adjustment mainly refers to the sudden explosion phenomenon of pneumatic height-adjustable swivel chairs caused by component defects, which mostly occurs in low-quality pneumatic rod products.

Causes of Explosion

• Thin Wall of the Pneumatic Rod: To reduce costs, low-quality pneumatic rods have insufficient wall thickness and cannot withstand the internal gas pressure, making them prone to rupture during frequent use or temperature changes.
• Insufficient Purity or Substitution of Inert Gas: Regular pneumatic rods are filled with nitrogen (an inert gas), which can withstand high pressure and is stable and safe. However, some merchants, for profit, substitute compressed air for nitrogen or mix in impurities such as oxygen. When the gas purity is insufficient, high temperatures or friction may trigger chemical reactions, leading to explosions.
• Sudden Temperature Increase Due to Frequent Height Adjustment: Pneumatic rods achieve height adjustment through pressure differences. Frequent operation causes internal gas friction and heat generation. If the gas purity is insufficient or the wall of the rod is too thin, the accumulated heat may trigger an explosion.

Typical Cases

• In 2007, a chair explosion occurred in Zhoushan, Zhejiang Province;
• In 2009, a 14-year-old boy in Jiaozhou, Shandong Province, died after a top rod of a pneumatic chair pierced his body while adjusting it;
• In 2013, Ms. Liu in Fujian Province was sitting on a swivel chair blow-drying her hair when the chair exploded. A steel tube about two centimeters in diameter shot out, piercing her lower body. Various fragments were removed from her abdominal cavity;
• In 2017, an office chair explosion in Anhui Province damaged a computer case;
• In 2020, a spot check found that some staff chairs produced by certain enterprises posed an explosion risk.

Preventive Measures

• Purchase Regular Products: Prioritize products priced above 200 yuan with regular certifications (such as SGS, BIFMA, etc.) and avoid purchasing "three-no" pneumatic rods.
• Check for Explosion-Proof Design: Ensure that a explosion-proof steel plate with a thickness of ≥2 millimeters is installed between the seat cushion and the pneumatic rod to effectively block explosion fragments.
• Standardize Usage Operations: Avoid violent height adjustments (such as pressing hard or rotating quickly) and do not disassemble the pneumatic rod without authorization to prevent damage to the internal structure.
• Regular Inspections and Maintenance: If the pneumatic rod experiences stuttering during height adjustment, makes a hissing sound, or shows surface rust, stop using it immediately and replace it.