Office Chair Spring Incident

Explosion incidents related to office chairs mainly involve pneumatic rods, not springs. Currently, there are no reports of an 'office chair spring incident'. The following provides an explanation from four aspects: explosion principles, typical accident cases, explosion causes, and preventive measures.

1. Explosion Principle of Pneumatic Rods
Pneumatic rods are the core components of adjustable-height chairs, essentially miniature pressure vessels that achieve height adjustment by regulating internal air pressure. Legitimate products are filled with inert nitrogen (chemically stable and highly safe), but inferior products may use compressed air or low-purity nitrogen. These gases can easily cause oxidation of metal components and accumulate internal heat. When the pressure exceeds the tolerance limit of the tube wall, an explosion may occur.

2. Typical Accident Cases

• In 2013, Ms. Liu was sitting on a rotating chair purchased online while blow-drying her hair when the pneumatic rod exploded. A steel column with a diameter of 3 centimeters pierced her lower body, entered her uterus, and a large amount of metal fragments were cleared from her abdominal cavity.
• In 2009, a 14-year-old boy named Xiaogang in Jiaozhou, Shandong, was adjusting a pneumatic chair when the rod pierced his body, resulting in death from excessive blood loss.
• In 2010, Xiaoxue in Xiamen was sitting on an adjustable-height chair while blow-drying her hair when the chair exploded, shooting screws and gaskets into her body and causing rectal tears.

3. Explosion Causes

• Material Defects: The tube wall of the pneumatic rod is too thin (standard requirement ≥ 2.0 millimeters), making it prone to rupture when the pressure exceeds the tolerance limit.
• Gas Issues: Leakage of the sealing ring, insufficient purity of nitrogen, or replacement with compressed air can lead to oxidation reactions and heat accumulation.
• Improper Use: Sitting down forcefully, frequently adjusting the height, or sliding the chair can accelerate wear and uneven force distribution on the pneumatic rod, increasing the risk of explosion.

4. Preventive Measures

• Purchase Legitimate Products: Prioritize brands certified by SGS or BIFMA (such as Sihoo) and avoid buying 'three-no' products (products with no brand, no factory name, and no production license).
• Inspect Key Components: Ensure the pneumatic rod adjusts smoothly and that a blast-resistant steel plate with a thickness of ≥ 2 millimeters is installed between the seat cushion and the pneumatic rod to cushion the impact of an explosion.
• Standardize Usage Habits: Avoid frequently adjusting the height or sitting down forcefully to reduce the risk of uneven force distribution on the pneumatic rod; regularly inspect the appearance of the pneumatic rod and immediately stop using and replace it if leakage, deformation, or abnormal noises are found.

Currently, office chair springs have not been reported to pose an explosion risk, but the safety issues of pneumatic rods require attention. By standardizing purchase and use, the probability of accidents can be effectively reduced.