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IS 11525:1986 is the Indian Standard (BIS) for wooden chairs for office purposes. This standard specifies the material, dimensional, constructional, and performance requirements for various types of wooden chairs intended for office use. It covers three types: typist's, junior executive's, and senior executive's chairs, and outlines tests for stability, strength, and durability.
ANSI/BIFMA X5.1-2017 (R2022)BIFMA (Business and Institutional Furniture Manufacturer's Association), USA
LowCurrent
General-Purpose Office Chairs — Tests
Covers safety, durability, and structural performance of office chairs, but is performance-based and material-agnostic, unlike the prescriptive IS code.
EN 1335-1:2020 & EN 1335-2:2018CEN (European Committee for Standardization), Europe
MediumCurrent
Office furniture - Office work chair - Part 1: Dimensions - Determination of dimensions / Part 2: Safety requirements
Specifies dimensions, safety, and stability for office chairs, but focuses on performance and ergonomics rather than prescribing materials like wood.
BS 5459-2:2000+A2:2008BSI (British Standards Institution), UK
LowWithdrawn
Specification for performance requirements and tests for office furniture - Part 2: Office seating for use by persons weighing up to 150 kg and for use up to 24 hours a day
A performance-based standard for heavy-duty/24-hour office seating, far more rigorous than the basic requirements of IS 11525.
AS/NZS 4438:1997Standards Australia/Standards New Zealand
LowCurrent
Height adjustable swivel chairs
Focuses on performance testing (stability, strength, durability) for swivel chairs, not specific to wooden construction.
Key Differences
≠IS 11525 is a prescriptive standard, specifying exact materials (e.g., Teak, Rosewood), moisture content, and construction methods (e.g., mortise and tenon joints). International standards are performance-based, allowing any material or construction that passes the required tests.
≠Modern international standards like BIFMA X5.1 and EN 1335 include rigorous cyclic (durability) and dynamic (impact/drop) testing to simulate long-term use, which are completely absent in IS 11525.
≠IS 11525 specifies fixed dimensions for different chair types. In contrast, EN 1335-1 emphasizes ergonomic design through specified ranges of adjustability (e.g., seat height, depth) to accommodate a wider range of users.
≠The load requirements for static tests in international standards are generally higher and more comprehensive, testing multiple load points and combinations not considered in the simpler IS 11525 tests.
Key Similarities
≈Both IS 11525 and its international counterparts have the fundamental objective of ensuring the chair is structurally sound and safe for use in an office environment.
≈Both standard types include requirements for stability to prevent the chair from tipping over forwards, sideways, or rearwards, although the test methods and forces differ.
≈All standards specify static load tests on the seat and backrest to ensure they can withstand the weight and force of a user. This is a core principle of chair safety assessment across all standards.
≈The scope of application is similar, as all are intended for chairs designated for office or institutional purposes, distinct from domestic seating.
Parameter Comparison
Parameter
IS Value
International
Source
Seat Static Load Test
110 kgf (approx. 1079 N) applied for 10 minutes.
1112 N (250 lbf) proof load applied 10 times.
ANSI/BIFMA X5.1-2017
Backrest Static Load Test
45 kgf (approx. 441 N) applied to the top of the backrest.
667 N (150 lbf) proof load applied to the backrest.
ANSI/BIFMA X5.1-2017
Rearward Stability Test
Chair with 65 kg on seat must not tip when a 20 kgf (196 N) horizontal force is applied at the top of the backrest.
Chair with 61 kg on seat must not tip when a 173 N horizontal force is applied at the point that most likely causes tipping.
ANSI/BIFMA X5.1-2017
Seat Durability (Cyclic Impact)
Not specified.
100,000 cycles of a 75 kg (165 lb) mass dropping from 25 mm (1 in).
EN 1335-3:2009 (Test method for EN 1335-2)
Backrest Durability (Cyclic)
Not specified.
120,000 cycles with a 334 N (75 lbf) force.
ANSI/BIFMA X5.1-2017
Seat Height (Type A chair)
Fixed at 450 mm.
Adjustable range of 420 mm to 500 mm.
EN 1335-1:2020
Timber Moisture Content
8% to 12% for all timber components.
Not specified; material properties are the manufacturer's responsibility to ensure performance.
ANSI/BIFMA X5.1-2017
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Maximum moisture content of wood12 %
Seat height (Typist's chair)430 to 580 mm
Backwards overturning minimum force200 N
Seat static load test1300 N for 10 cycles
Back static load test560 N for 10 cycles
Arm rest downward static load test900 N
Tables & Referenced Sections
Key Tables
Table 1 - Dimensional Requirements for Office Chairs
Table 2 - Performance Requirements for Office Chairs