EN 1335 or BIFMA: what to ask for, and what neither standard tells you
Both standards appear in almost every office seating tender, and almost every supplier claims both. Two things are rarely said. BIFMA states that it does not test products and that no manufacturer should write “BIFMA Certified” — we wrote it ourselves until 30 October 2026. And EN 1335 says nothing at all about how long your fabric will last.
What each one actually covers
They are not competing standards and one does not replace the other. EN 1335 is the European reference for office work chairs; ANSI/BIFMA X5.1 is the North American one. A chair sold on both continents is normally assessed against both.
| Reference | What it specifies | What it does not |
|---|---|---|
| EN 1335-1 | Dimensions of office work chairs and the methods for determining them | Says nothing about strength or safety |
| EN 1335-2 | Safety, strength and durability requirements | Contains the requirements, not the test procedures |
| EN 1335-3 | Test methods — stability, strength and durability on a fully assembled chair, under normal use and foreseeable misuse | Explicitly excludes ageing, and the durability of upholstery, filling materials and covers |
| ANSI/BIFMA X5.1 | General-Purpose Office Chairs – Tests. Around twenty mechanical tests of safety, durability and structural adequacy | Is a test standard, not a certification scheme |
Editions matter and are routinely omitted. EN 1335-1 was revised in 2020, so a report citing an earlier edition is not wrong — but you should know which one you are being shown.
BIFMA does not certify anything, and says so itself
In a conformance memo dated 25 October 2016, BIFMA sets out how a manufacturer may and may not describe its products. The three sentences below are BIFMA’s, not ours.
BIFMA does not test products
“BIFMA does not test products nor does BIFMA track or monitor test conformance.” Testing is done by a laboratory, not by the association, and the association keeps no register of who passed.
Three phrases that should not be used
“Manufacturers should not state ‘BIFMA Approved’, ‘BIFMA Certified’, or ‘BIFMA Tested’ in conformance claims.” If a supplier’s catalogue uses one of them, it tells you how carefully the file behind it was assembled.
Membership proves nothing about the product
“Membership in the BIFMA organization is an independent issue from product conformance testing.” A supplier who answers a conformance question by naming its memberships has not answered it.
What a correct declaration looks like
The declaration is issued by the manufacturer or the testing body, and names the full reference, the title and the year: “This product meets or exceeds the applicable requirements of ANSI/BIFMA X5.1-2011 General-Purpose Office Chairs – Tests.”
We used the wrong wording, on fifty-nine lines of this site
This page would be worthless as an accusation aimed at other suppliers, so here is where we stood. Until 30 October 2026 this site said “BIFMA certified” in English, French and Portuguese, fifty-nine times across twenty-five files. It now says that our chairs conform to ANSI/BIFMA X5.1-2011, which is the claim we can actually support and the wording BIFMA asks for.
What changed
The claim did not change — the attribution did. Our chairs were tested against the same standard before and after the correction. What was wrong was crediting the certification to an association that does not certify.
Why it is worth a paragraph
Because the same error is on most of our competitors’ sites, and because a buyer who reads this now knows the question to ask all of us. That is a fairer basis for a comparison than a badge.
Neither standard tells you how long the fabric lasts
This is the part that costs money three years in, and it is in the standard in black and white: EN 1335-3 states that its tests are not intended to assess the durability of upholstery — filling materials and covers — and that assessment of ageing and degradation is not included.
What the mechanical standard proves
That the chair does not break, does not tip, and survives the prescribed cycles. That is a safety and structural guarantee, and it is a real one.
What it leaves entirely to you
How the cover wears, how the foam settles, how the colour holds. These are properties of the textile and the foam, tested by their own methods, and they have to be specified separately in the tender.
The practical consequence
Two chairs can hold the same mechanical report and wear out years apart. If the tender names only EN 1335 and ANSI/BIFMA X5.1, it has not specified the part your users will actually touch.
A standard is not a customs formality
Neither standard is something customs asks for. They are commercial and tender requirements. Treating a conformance report as an import document is a common and avoidable confusion.
Three documents, and the questions they answer
A certificate summary on a supplier’s letterhead answers none of these. Ask for the file itself, before the order rather than after.
| Ask for | What you are checking | What a weak answer looks like |
|---|---|---|
| The full test report | The laboratory’s name, and that it is accredited to ISO/IEC 17025 with the relevant standard inside its scope of accreditation — which is what BIFMA itself recommends | A one-page certificate with a logo and no laboratory named |
| The model and configuration tested | That the report covers the chair you are buying, in the configuration you are buying — a report on one model does not cover a range | “Our chairs are certified”, with no model named |
| The edition and the date | The full alphanumeric reference, the title and the year of the standard, as the declaration is supposed to carry | “BIFMA” or “EN 1335” with no part, no edition and no year |
These three questions take one email and settle more than a factory visit does. They are also the questions we expect you to put to us — our reports go out with the quotation, not after the order.
EN 1335 and ANSI/BIFMA X5.1, plainly
Can a chair be “BIFMA certified”?
No. In its conformance memo of 25 October 2016, BIFMA states that it does not test products and does not track or monitor test conformance, and that manufacturers should not state “BIFMA Approved”, “BIFMA Certified” or “BIFMA Tested” in conformance claims. The correct form is a declaration of conformance naming the full reference, title and year of the standard, issued by the manufacturer or the testing body.
What does EN 1335 not cover?
Upholstery. EN 1335-3 states that its tests are not intended to assess the durability of upholstery — filling materials and covers — and that assessment of ageing and degradation is not included. Fabric and foam performance has to be specified separately, by its own test methods.
Which edition should the report cite?
Whichever one it was tested against, stated explicitly. EN 1335-1 was revised in 2020, so an older edition may legitimately appear on an older report — the problem is a report that names no edition at all. ANSI/BIFMA declarations are expected to carry the full reference, title and year, for example ANSI/BIFMA X5.1-2011.
Is EN 1335 compulsory in Europe?
It is the reference European public bodies and large companies write into their tenders, and conformity is demonstrated voluntarily through third-party testing. It is not a customs formality: your broker will not ask for it, your buyer will.
Does BIFMA membership mean a supplier’s chairs are compliant?
No, and BIFMA says so directly: membership in the organisation is an independent issue from product conformance testing. Membership is a trade association subscription; conformance is a laboratory report.
What does KWESK hold?
Our chairs conform to ANSI/BIFMA X5.1-2011 and to EN 1335-1-2-3:2016. We supply the reports with the quotation rather than after the order, so that the three checks on this page can be made before you commit to anything.
Ask us the three questions first
If this page is useful, use it on every supplier you are comparing, including us. We would rather be chosen on a report than on a badge.