Compressed Office Chair Explosion

Compressed office chairs (pneumatic lift type) can indeed explode, mainly due to component defects in inferior pneumatic rods. The causes, cases, and preventive measures are as follows:

Causes of Explosion

1. Insufficient Gas Purity
   Standard pneumatic rods should be filled with inert nitrogen with a purity of ≥99%. However, inferior products often use ordinary compressed air instead. The oxygen in the air reacts with the metal inner wall through oxidation, leading to rusting, heat accumulation, and a continuous increase in internal pressure, ultimately triggering an explosion.

2. Thin Tube Walls
   The wall thickness of qualified pneumatic rods should be ≥2 millimeters, while inferior products often have walls less than 2 millimeters thick, unable to withstand the internal high pressure. When the pressure reaches a critical point, the tube wall suddenly bursts, releasing a large amount of energy.

3. Lack of Explosion-Proof Measures
   Some products are not equipped with explosion-proof steel plates with a thickness of ≥2 millimeters. During an explosion, metal fragments can directly penetrate the chair surface, causing serious injuries. Explosion-proof steel plates are crucial for blocking fragment splatter.

4. Improper Use
   Frequent lifting and lowering can cause a sudden increase in the temperature of the pneumatic rod. Long-term exposure to high-temperature environments (such as heating and direct sunlight) accelerates material aging, increasing the risk of explosion.

Typical Cases

• 2013: Ms. Liu was sitting on an online-purchased lifting swivel chair to blow-dry her hair when the pneumatic rod exploded. A steel rod with a diameter of 3 centimeters pierced through her body, and doctors removed more than ten metal fragments from her abdomen and intestines.
• 2009: A 14-year-old boy in Jiaozhou, Shandong, died after adjusting a pneumatic chair, causing the top rod to pierce his body.
• 2017: An office chair in Anhui exploded, and the impact damaged a computer case.
• 2020: A spot check by the State Administration for Market Regulation revealed that 23.3% of office chairs were unqualified, with 17 batches being swivel chairs. The main issues were the failure of pneumatic rods to meet high- and low-temperature resistance standards and the lack of explosion-proof steel plates.

Preventive Measures

1. Choose Standard Products: Prioritize products priced over 200 yuan that have passed the QB/T2280-2016 standard certification and check if the pneumatic rod has a 5G5 certification.
2. Check for Explosion-Proof Steel Plates: Ensure that an explosion-proof steel plate with a thickness of ≥2 millimeters is installed between the seat cushion and the pneumatic rod.
3. Avoid Frequent Lifting and Lowering: Limit the number of daily lifts and keep the chair away from high-temperature environments.
4. Regular Inspections: If the pneumatic rod experiences sticking, unusual noises, or surface rust during lifting and lowering, stop using it immediately.