Office chair standards: EN 1335 vs BIFMA X5.1 for task chairs made in Turkey

A task chair from Turkey is bought against one of two families of standards: EN 1335 in Europe, the UK and most tenders that follow European practice, or ANSI/BIFMA X5.1 in the US. They answer different questions. EN 1335 says what size and shape the chair must be and how strong; BIFMA X5.1 says how hard it is tested, and both leave the fire test to a separate standard.

EN 1335 vs BIFMA X5.1

Sources: CEN catalogue (EN 1335-1, EN 1335-2, EN 16139), BIFMA standards descriptions and BIFMA Compliant.

The parts of EN 1335

Part 1, dimensions. Four chair types. Type Ax has the largest range of adjustment; Type A a large range; Type B a range; Type C limited adjustment (EN 1335-1, clauses 3.2–3.5). Seat height, seat depth, backrest height and armrest height are measured in a set order. Since January 2026, CEN/TS 18231 explains how to take those measurements with the ISO 24496 chair measurement device, to make them more precise and less open to reading.

Part 2, safety. Requirements for safety, strength and durability, based on 8 hours a day by people up to 110 kg, with the loads and cycles for the functional tests in Annex A.

Part 3 is gone. EN 1335-2:2018 replaced EN 1335-3:2009, the old test-methods part. A specification that still asks for “EN 1335-1, -2 and -3” is copied from an old template; the current pair is Part 1 and Part 2:2018.

EN 1728 is a method, not a pass mark. It describes how seating of every kind is loaded and cycled, and contains no requirements. A report that cites EN 1728 alone shows a chair was tested, not that it passed a level for office use.

Chairs EN 1335 does not cover

A meeting room, reception or breakout area has chairs that are not work chairs. In Europe they are tested to EN 16139:2025, written for non-domestic seating used by adults up to 110 kg. It names office visitor chairs inside its scope and office work chairs outside it. In the US the same chairs fall under X5.1 (side and guest chairs) or, for lounge and waiting seating, ANSI/BIFMA X5.4-2020(R2025).

Fire is a separate line

What to write on a BOQ line

A task chair line that a Turkish partner factory can price without a round of questions names the type, the standard and edition, the fire test and the report. Two examples:

EU / UK: Task chair, EN 1335-1:2020+A1:2022 Type A, synchronised mechanism, 2D arms, adjustable lumbar. Tested to EN 1335-2:2018, report attached. Fabric to BS 7176 medium hazard (UK) / EN 1021-1 and -2 (EU). Qty 100.

US: Task chair, tested to ANSI/BIFMA X5.1-2017(R2022), report attached; X5.11 for the large-occupant positions (qty 6). Upholstery to 16 CFR 1640 / TB 117-2013 with the label. Qty 100.

For counters and high benches, EN 1335-1 defines a tall office work chair, with a seat higher than the normal maximum and a foot support; name it on its own line.

How Rovers prices task chairs

We price task and operational seating with Turkish partner factories and brands that already build to EN 1335 or BIFMA X5.1, and the test report from the maker goes with the line it covers. The chair line sits in the same schedule as the desks, storage and joinery of the office fit-out, delivered floor by floor; outside the US we install, in the US we deliver.

What to send us

Send the furniture schedule or the BOQ, the market the floor is in, and the standard your specifier wrote on the chair lines. If no standard is named yet, tell us the market and we will put the matching one on each line of the priced schedule.