IM stands for upholstered (imbottito). In a Class 1 IM test, the sample entering the laboratory is the assembled piece: frame, padding and covering tested in the same combination in which they will end up in the room. From this detail, which at first glance looks like a laboratory formality, follows almost everything a hotelier needs to know on the subject, starting with the fact that reupholstering successfully on the aesthetic side can wipe out a perfectly valid approval.
It is worth rebuilding the reasoning from the start, because the chain of consequences is long and touches decisions made at the specification stage, well before any inspection.
Contents
Why Class 1 IM is tested on the complete upholstered piece and not on the fabric alone
When a small flame reaches an armchair, a dropped cigarette or a match, it does not immediately find the mass that burns. It finds the covering, which is a thin layer. Underneath lies the real energy reserve: a polyurethane foam, or a fibre, which are porous materials, full of air and with an enormous surface area relative to their weight. The decisive moment in an upholstered fire is the flame passing from the outer layer to the core.
Testing the fabric and the foam separately would say little about that transition. Two materials that behave acceptably on their own can worsen each other’s behaviour once paired: a covering that melts and drips onto a foam ignites it more readily than a covering that chars. The opposite also holds, and it is not unusual to see combinations where a mediocre fabric on a suitable foam holds up better than expected. IM classification exists to measure exactly this, which is why the test sample is the paired assembly.
Reupholstering an approved piece: why it voids Class 1 IM
The approval covers a configuration, not a generic model. Replacing the fabric of an approved armchair means stepping outside that configuration, unless the new fabric-padding combination is itself covered by a test.
This is the point where most properties trip up, and almost always in good faith. A hotelier reupholsters the twelve lobby armchairs with a contract fabric chosen by the interior designer, perhaps an excellent fabric rated at 60,000 Martindale cycles. On the wear front, they have improved things. On the paperwork front, they have just turned twelve approved armchairs into twelve armchairs with no valid certification, and they will find out two years later, when someone asks for the paperwork.
The only question to ask the manufacturer before reupholstering is this: is that fabric already included in a test paired with that padding? The answer is yes or no, and it changes everything that follows.
Which hotel furnishings must be Class 1 IM
Within the scope of upholstered items fall room armchairs and small armchairs, sofas, pouffes, benches and upholstered seating, chairs with an upholstered seat or backrest even when the padding is minimal, mattresses, and upholstered divan bases and bed bases. Sofa beds for hotels count twice, because on top of the upholstered structure they have an internal mattress that is itself an upholstered item. Decorative cushions and headboard covers need assessing case by case with the technician handling the paperwork.
Rigid furnishings stay outside the scope: wardrobes, bedside tables, desks, minibar cabinets, mirror units. For these, the question of fire reaction shifts to the surface finish when the furniture forms large continuous surfaces against a wall, but IM approval does not apply to them.
The most underestimated element is upholstered hotel headboards. They are often commissioned from a local upholsterer outside the main supply, arrive with no paperwork and nobody mentally links them to the armchairs. Yet they cover two metres of wall behind every bed and are the first thing noticed on entering the room.
Mattresses regularly fall outside the reasoning too. Renewing the mattresses across forty rooms is an upholstered-goods supply in every respect, with the documentation that follows from it.
Fireproof, fire-treated and approved: the differences that matter
In commercial language, the three words get used as synonyms. They describe different things, and the difference is exactly what a fire brigade inspection assesses.
An intrinsically fireproof material has the property built into the fibre or the polymer: modified polyesters, aramid fibres, foams with additives already in the formulation. The characteristic does not wash out and does not wear away with use.
A fire-treated material is an ordinary material to which a flame retardant has been applied, either by dipping during production or by spraying after installation. It works for as long as the product remains on the fibre, so it has a declared duration and needs renewing. Whoever carries out the treatment issues a declaration with the application date and expiry. In a hotel, where fabrics go through the laundry regularly, the real expiry arrives before the nominal one.
Approved, on the other hand, is a documentary status: that piece, in that configuration, has passed tests at an authorised laboratory and has an approval number. Of the three conditions, it is the only one that can be produced as evidence. An inspector has no way of checking on site that a foam is fireproof throughout its mass; they read a document.
Sprayed fire-retardant treatment on upholstery: limits and alternatives
Spray treatment applied to finished pieces is the shortcut that always turns up when the problem is noticed too late. On an upholstered piece it has one physical limit and one documentary limit.
The physical limit is that it acts on the outer surface, while the behaviour the IM test measures depends on the internal padding. A film on the covering does not change the whole, and the penetration achieved by hand on an already-assembled armchair cannot be controlled: in the factory the fabric is treated in a bath with measured quantities, in the room it depends on the operator and the bottle.
The documentary limit is that the treatment produces a declaration of treatment carried out, with limited validity, which is not a Class 1 IM approval and does not replace it.
On curtains, textile wall coverings and non-replaceable decorative elements, on the other hand, after-the-fact treatment remains a viable and commonly accepted route, provided it is documented and renewed on expiry. The difference is that there the material is entirely on the surface.
Class 1 and Class 1 IM: differences and fire-reaction classes
Class 1 without a suffix applies to materials: a fabric, a carpet, a panel, a technical wallpaper. The tested sample is the material. Class 1 IM applies to upholstered pieces, with the test sample representing the whole assembly. Asking for the Class 1 rating of a fabric and assuming the armchair it covers is thereby certified is by far the most common misunderstanding.
The Italian system classifies materials on a scale where the lower number indicates better behaviour.
| Class | Behaviour |
|---|---|
| 0 | Non-combustible: metal, glass, stone, brick |
| 1 | Combustible with very low fire reaction |
| 2 | Contained fire reaction |
| 3 | Intermediate fire reaction |
| 4 and 5 | High fire reaction, excluded from escape routes |
Alongside this scale runs the European classification, with Euroclasses from A1 to F and two additional indices: s for smoke production, d for dripping. A curtain might therefore arrive with a code such as B-s1,d0. In Italian hotel practice, the two languages coexist, and when the supplier delivers a European document while the designer was expecting an Italian one, the conversion needs clarifying in writing between the two technicians before the material is installed.
When the hotel has to prove the approval: SCIA, inspections and claims
Two situations are predictable. The first is submitting the fire-safety SCIA notice after a refurbishment or a change of use, when the professional collects the furniture declarations to attach to it: if they are missing, the paperwork stalls, and with it often the opening. The second is a periodic or spot-check inspection, which verifies whether what is declared matches what is actually there: model, quantity, covering.
Armchairs reupholstered in a fabric different from the one stated in the document are a discrepancy visible to the naked eye. The fire-reaction class required for furnishings follows from fire-safety regulations and from the bed-capacity threshold, which determines the procedure the property is subject to.
The third moment is the one nobody budgets for: a claim. An insurer can dispute cover if it emerges that the installed furnishings did not meet the requirements for that type of business. The extra cost avoided by choosing hotel armchairs without approval, indicatively a few percentage points on an upholstery supply for twenty rooms, bears no proportion at all to that exposure.
There is, finally, a mistake that has nothing to do with the products but with memory: buying compliant furniture and being unable to prove it two years later, because the documents stayed in the inbox of a manager who has since left. Every piece needs to come with its fire-resistance certificate, with a test report, declaration of conformity and approval that must match the delivered furniture item by item.
Frequently Asked Questions
What exactly does the IM designation mean?
IM stands for upholstered (imbottito) and identifies the fire-reaction classification reserved for upholstered furniture. The test is carried out on a sample representing the whole assembly made up of frame, padding and covering. It differs from plain Class 1, which applies to materials such as fabrics, carpets or wall coverings tested individually.
If I change the fabric of an approved sofa, does it stay compliant?
Not automatically. IM approval covers the specific combination of frame, padding and covering brought to the laboratory, so replacing the fabric takes it outside that configuration. You need to ask the manufacturer whether the new covering is already covered by a test paired with that padding; if not, a new test or a new piece is needed.
Can I have my existing armchairs spray-treated?
On an upholstered piece, surface treatment does not produce a Class 1 IM approval, because it does not change the behaviour of the internal padding, which is the determining factor. For curtains and textile wall coverings, treatment carried out by a specialist company is instead a documentable route, with limited validity over time and needing renewal on expiry.
Do mattresses fall under IM classification?
Yes, a mattress is an upholstered item. Renewing the mattresses across a whole floor is an upholstered-goods supply, and whoever delivers them must issue the corresponding documentation referring to the batch actually delivered, not a generic catalogue document. The same applies to the internal mattresses of sofa beds.
