How to tell if a curtain is fire retardant? 4 reliable checks

A curtain delivered with the mention "fire-retardant" on its label is not necessarily compliant with the M1 or M2 requirements expected in a public-access building (ERP). The difference between the commercial claim and the regulatory proof determines the operator's legal responsibility during a safety commission visit or an incident. This article details the four possible verifications, their limits, and their enforceable value.

For obligations applicable by area, see our M1/M2 ERP regulations guide. To understand the fabric material, read the article on the three families of fire-retardant fabrics. To make a non-compliant curtain compliant, consult the three post-manufacturing fire-retardant methods.

Why verify that a curtain is actually fire-retardant?

Three issues justify rigorous verification, especially for a B2B fleet.

1. ERP Compliance. The safety commission checks the register during each visit (3 years for most ERPs, 5 years for category 5 establishments). In the absence of a traceable report, an unfavorable opinion is possible, regardless of the actual quality of the fabric.
2. Multi-risk insurance. Fire contracts almost always include a forfeiture clause in case of material non-compliance. An incident involving a curtain presented as M1 without documentary proof can lead to a refusal of coverage.
3. Civil and criminal liability. In the event of a fire-related accident, the operator must prove that they exercised due diligence, which includes active verification of installed materials, not just relying on the supplier's label.

Four verifications make it possible to cover these three issues, with very different levels of proof.

Method 1 — The curtain's technical label

The label is the first and most accessible reflex. On a fire-retardant curtain, it must mention at least: the fiber composition (for example, "100% inherently fire-retardant polyester"), the classification obtained (M1, M2, or Euroclass B-s1, d0), and ideally the reference of the weaver or yarn used.

What the label proves: that the manufacturer declares a classification. This is a commercial declaration, not normative proof.

What the label does not prove: the authenticity of the classification, its date of obtainment, its maintenance over time (a chemically treated fire-retardant fabric loses its classification after several washes; the label does not indicate this degradation), nor the traceability to the original test report.

In a safety commission, the label alone is never enforceable. It can at most refer to a report to be requested from the supplier.

Method 2 — The M classification report

The report (PV - procès-verbal) is the only legally enforceable proof of a fabric's classification in France. It is issued by a recognized laboratory after standardized testing according to NF P 92-507 standard. Three laboratories account for the vast majority of reports in France.

• CSTB (Centre Scientifique et Technique du Bâtiment) — historical reference for buildings.
• LNE (Laboratoire National de métrologie et d'Essais) — versatile state laboratory.
• IFTH (Institut Français du Textile et de l'Habillement) — textile specialist.

An exploitable report contains five mandatory pieces of information.

1. The name and signature of the issuing laboratory.
2. The test date and the report issue date.
3. Precise identification of the tested fabric (commercial reference, composition, weight).
4. The normative result (class M0, M1, M2, M3, M4 and, if applicable, Euroclass B/C/D).
5. Test conditions, especially if the fabric was tested after washing (M1 confirmed after X cycles).

A report that does not mention the test date, the issuing laboratory, or the exact fabric reference is not enforceable. Request the complete PDF version, not an extract or an attestation drafted by the supplier.

Method 3 — The at-home wick test

The wick test is a simple physical verification: a thread is taken from an inconspicuous part of the curtain (inner hem, excess seam), placed on a non-flammable surface, approached with a small flame, and its behavior is observed. An M1 fabric does not ignite durably and self-extinguishes as soon as the flame is removed.

What the wick test proves: physical behavior consistent with an M classification. If the wick burns brightly and is self-sustaining, the fabric is not M1, period.

What the wick test does not prove: the exact classification (M1 or M2 cannot be distinguished with the naked eye), regulatory compliance (the test has no value in a safety commission), nor the maintenance of classification after washing.

The test remains useful for detecting gross fraud (curtain presented as M1 but which clearly ignites) before engaging a more formal procedure for requesting a report.

Method 4 — Direct inquiry to the supplier

For a B2B fleet, the most comprehensive method involves asking the supplier in writing. Five questions frame the verification.

1. What is the exact fiber composition of the fabric? Expected answer: percentage by fiber, polymer type (inherently fire-retardant polyester, fire-retardant viscose, cotton or linen with chemical treatment).
2. Is M1 classification inherent or by chemical treatment? Inherent answer = lifetime classification; treatment = limited duration to be specified.
3. Which laboratory issued the classification report, and on what date? Expected answer: name of the laboratory (CSTB, LNE or IFTH) and test date less than 5 years old.
4. Can you send me the report in PDF format? Expected answer: sent within 48 hours. Any hesitation or evasive answer is a red flag.
5. What is the guaranteed duration of industrial washing resistance? Expected answer: number of guaranteed cycles and washing conditions (temperature, compatible products).

Keep the answers in writing (email, technical data sheet). They are part of commercial traceability and can be produced in case of dispute.

Comparison of the four methods

The right approach combines all four. The label provides an initial reading, the wick test helps rule out gross fraud, the request to the supplier reveals the quality of commercial follow-up, and the report is the key document to keep in the safety register.

Special cases to monitor

Curtain inherited from a previous operator

When taking over a business or changing management, curtains may remain in place without documentation. Systematically request the safety register from the previous operator. In its absence, have a retest performed by a laboratory (€300 to €800 depending on complexity) or replace it.

Curtain imported from outside the European Union

Foreign classifications (US NFPA 701, British BS 5867, German DIN 4102) are not equivalent to the French M classification. A foreign declaration of conformity does not exempt from the NF P 92-507 test if the curtain is installed in an ERP in France. The only case where European classification (Euroclasses A to F) is admitted is that provided by the decree of November 21, 2002, with a precise correspondence table.

Report older than 5 years

The NF P 92-507 standard does not set a legal validity period for the report, but control offices (Bureau Veritas, Apave, Socotec) recommend a recent report. A report older than 5 years may be subject to a retest request, especially if the fabric composition has evolved at the weaver's since the initial test.

What to do if the curtain does not pass verification?

Three options are available depending on the severity of the defect.

• The curtain is physically M1 but without a traceable report: order a retest from CSTB, LNE, or IFTH. Indicative cost €300 to €800. Lead time 4 to 8 weeks. The report obtained is valid for the tested fabric, not for another batch.
• The curtain is not fire-retardant but is recent: consider post-manufacturing fire-retardant treatment (workshop saturation or on-site application) with a report issued by a certified workshop. Our dedicated article details the three methods and their actual lifespan.
• The curtain is not fire-retardant and is worn: replace it with a new inherently M1-classified fire-retardant curtain from the outset. This is the most durable and least expensive solution over 10 years for a significant fleet.

Kurtens traceability in B2B

Kurtens provides with each fire-retardant B2B order the nominal M classification report dated from the weaver, in PDF version transmitted with the delivery. The report is included in the commissioning slip, ready to be attached to the operator's safety register. M1 certification is available upon request for all manufactures, with any additional cost integrated into the quote without a separate line.

For a project to replace or upgrade a fleet, see the custom fire-retardant curtains page or request a B2B quote. Response within 24 hours.

Frequently asked questions about checking a fire-retardant curtain

Regulatory note: this article presents practical methods for verifying the classification of a curtain with regard to the French framework NF P 92-507 and the decree of June 25, 1980. It does not replace consultation with an approved control office. The validity of a classification in an ERP depends on complete documentary traceability and the specificities of the building.

For a project where M1 traceability is required upon delivery : request a B2B quote. Response within 24 hours, CSTB or IFTH report attached to delivery, M1 certification on request.