Chair Stability Tests Based on EN 1022 - A Simple Guide

The scope of EN 1022 standard is specific test methods and requirements to determine the stability of all types of seating for adults weighing up to 110 kg, disregard of use, materials, design, construction or manufacturing process.

The test methods described in the standard can be used for seating for children and heavier adults by modifying test loads and loading points, but this standard does not apply to children’s highchairs, table mounted chairs and bath seats which are covered by other European Standards.

This article will explain you how the laboratory will conduct tests according to the standard, so you can perform the tests in your facility by using simpler equipment. At least by doing it before the official tests, you can anticipate the failure and modify the product to guarantee a pass result.

Image: Folding chair under testing

There are 3 parts of tests: Forward Stability, Sideways Stability, and Rearward Stability.

Forward Stability

There are several steps to perform forward stability or overbalancing tests:
(1) Make sure there is stopper(s) on the floor for the front leg. The position of loading point is to be determined at anywhere that most likely to result in overturning, 60 mm behind the front edge of seat.
Not necessary at the center of the seat.

(2) Apply a vertical downward load of 600 Newtons on that point.

See an illustration drawing below:

(3) Apply horizontal force of 20 Newtons (by pulling force is recommended) and hold for 5 seconds.
If the chair is overbalancing forward, or the rear leg is lifted before 5 seconds, it means the chair is failed and you need to modify the construction and/or structure of the chair.

Sideways Stability

Sideways stability test has similar method with Forward Stability test. The main difference is the position of loading point. Sideways stability loading point is located 60 mm from the edge of side seat.
The horizontal force remain the same, and stopper(s) to be placed along the side leg.

(1) Place stopper(s) at the side legs
(2) Vertical downward load of 600 N
(3) Horizontal force of 20 N

For a chair with armrests, the vertical load is only 250 Newtons, and the loading point is 100 mm from the center of the seat. And for wide armrests, the loading point is 40 mm from the outer armrest.

Additional vertical load of 350 N is applied at the middle of armrest, but not less than 100 mm from the front edge of armrest. The horizontal force remain the same 20 N, with duration of 5 seconds.

Rearward Stability

Rearward stability test applied to the backrest that have a direct contact or the highest point.
Vertikal load of 600 N toe be applied on the seat, not at the center of the seat but at the center balance of front leg and back leg that touch the floor.

The horizontal load is calculated using this formula:

F = 0.2857 x (1000 - H) Newton

F = Force
H = Seat height from floor

H = 400 mm
F = 0.2857 x (1000 - 400) = 171,42 Newtons

The chair shall not overturned when applied horizontal force does not reach 171,42 N (or depends on the calculation with chair's seat height).

(1) Place the leg stopper behind the rear leg
(2) Define the vertical loading point on the seat
(3) Apply the vertical loading weight of 600 N
(4) Apply horizontal force to the backrest

Backward Fall Test

The process of this testing method is basic dan simple, and actually it is not included in the EN 1022 standard. This test is part of BS EN 12520 standard, a test method for indoor seating furniture. And it does not applied to outdoor seating furniture.

The testing is done to one seat chair by applying a force not more than 30 Newtons to the backrest, backward direction.
The force is repeated for 5 times.

Testing methods and steps:
1. Place the chair on a flat concrete floor without any stopper.
2. Define the point of force on the backrest, 50 mm from the top of the backrest.
3. Apply the force of 30 N to that point until the front leg lifted.
4. Continue apply the force until the front leg lifted and the chair stands on its 2 back leg. Measure the amount of force applied when the chair starts overturned. The maximum force applied is the maximum level of chair's stability.

If the maximum force is >30 Newton or higher, the chair has a good stability. Or if the chair is overturned easily without much force, most probably the chair will be FAILED at the laboratory test and it means the chair is not safe for the end users.

This test guidance is based on our experiences and knowledge, and it does not guarantee your product will pass the official test in the lab when you follow our guidelines.
It is recommended to perform all the tests at authorized and competent laboratory who has the expertise and correct equipment to perform these tests based on EN 1022 standard.


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