Office Chair Testing Criteria

The office chair testing criteria are primarily based on the EN 1335 standard system, covering three core modules: dimensions, safety, and testing methods, to ensure product safety, stability, and ergonomic compatibility.

I. EN 1335-1: Dimension Measurement

This section defines the size ranges for key components of office chairs to accommodate European adult users from the 5th percentile female to the 95th percentile male (approximately 1.55 meters to 1.9 meters in height). Core parameters include:

• Seat: Height and adjustment range, depth and width, tilt angle (if adjustable);
• Backrest: Height and width, height and depth of lumbar support points (to ensure effective lumbar support);
• Armrests: Height and spacing.
  Through precise measurements, the chair is ensured to meet the basic usage needs of users with different body types, preventing fatigue or injury caused by improper dimensions.

II. EN 1335-2: Safety Requirements

This section verifies the mechanical strength and stability of office chairs through multiple tests, including:

1. Stability Tests:
   • Chair legs must not lift off the ground during forward, backward, and lateral loading (e.g., armchairs must withstand a force of 600N);
   • The tilt angle must not exceed the design critical value, with the test platform tilting at a rate of 5 degrees per second, recording changes in contact points between the chair wheels and the ground;
   • Casters must be tested for locking function under horizontal thrust, failing if more than two casters lift off the ground when tilted 15 degrees.
2. Strength and Durability Tests:
   • Seat and Backrest Cycling Tests: The seat undergoes 100,000 vertical pulse loads (at a frequency of 30 cycles per minute), and the backrest completes 50,000 recline cycles (with a load of 350N), with a settlement of no more than 15mm;
   • Armrest Strength Test: A lateral force of 300N is applied for 1 minute, with deformation not exceeding 10% of the palm width;
   • Five-Star Base/Pedestal Strength Test: The safety factor must be 1.5 or higher;
   • Caster/Leg Durability Test: Repeated walking over several kilometers.
3. Impact Tests:
   • Seat Impact: A 50kg rigid hemisphere is dropped from a height of 20cm 10,000 times to check for structural cracks or deformation;
   • Backrest Impact: Tests resistance to sudden backward leaning forces.
4. Flame Retardancy Test: Upholstery and filling materials must comply with the EN 1021 standard, resisting ignition from cigarettes and matches.

III. EN 1335-3: Safety Testing Methods

Provides unified, repeatable operational specifications for the testing projects in EN 1335-2, including test equipment setup, force magnitude/direction/speed, and cycle counts, ensuring comparability of results across different laboratories. For example, in static load tests, the seat must withstand a vertical pressure of 120kg for 60 seconds, and the backrest must withstand a backward pull at a 45-degree angle to verify weld strength and leg bending resistance.

Additionally, EN 1335 includes special tests for swivel or reclining functions: the swivel mechanism must withstand 20,000 cycles of rotation at a torque of 35Nm; the reclining function must ensure that the relative displacement between the seat cushion and backrest is less than 8mm when the backrest is tilted, preventing clothing from getting caught.