“Is polystyrene fireproof?” It is one of the questions we are asked most often by architects, event managers and technical departments before they approve a set or an installation. The honest answer is: it depends on the type of EPS and on the treatment. In this guide we explain what fireproof EPS foamreally means, how reaction-to-fire classes work and which documents to ask for before an event open to the public.

Polystyrene foam and fire: let’s start with the facts

Expanded polystyrene (EPS) is an organic material and, like wood or fabrics, it can burn under standard conditions. That is why so-called self-extinguishingEPS has existed for decades: a version with added flame retardants that stops burning once the ignition source is removed. It is the material normally used in construction and in applications in contact with the public.

Reaction-to-fire classes in plain words

In Europe, the reaction to fire of materials is classified according to the EN 13501-1 standard, using the so-called Euroclasses: from A1 (non-combustible, like glass or steel) to F (no performance determined). For each class, smoke production (s1–s3) and flaming droplets (d0–d2) are also assessed. In Italy, for installations in places open to the public, fire prevention rules require materials with a certified and documented class — which one depends on the type of venue and its use.

• Standard EPS: no fire requirements; fine for private work, prototypes and controlled photo sets.
• Self-extinguishing EPS: with added retardants, it is the standard for construction and for many public applications.
• Treated or coated EPS: intumescent paints, resin coatings and certified finishes improve the performance of the exposed surface.

Fireproof foam for scenic fabrication and displays: treatments and coatings

In scenic fabrication, reaction to fire is decided mainly by the surface. An EPS sculpture coated in resin and painted with certified fire-retardant systems behaves very differently from the bare material: the resin coating creates a rigid, compact shell, and intumescent products add protection that activates with heat. That is why every project must be assessed as a whole: material, treatment, size, position and escape route.

What to ask your supplier before a public event

• The technical data sheet of the material used (type of EPS, density, any additives).
• The reaction-to-fire certificates for the treatments and coatings applied.
• A declaration of correct installation, when assembly affects safety.
• Who handles the paperwork with the safety inspection committee or the event’s safety manager.

If a supplier cannot answer these questions, that is a warning sign: certification cannot be improvised once the installation is finished.

How we handle certifications and documentation

We have been working with EPS foam since 2004 for trade fairs, retail, museums and public events in over 20 countries: managing certifications and paperwork is part of the service, in Italy and abroad, as we explain on the page Your production partner in Italy and worldwide. At quotation stage we analyse where the piece will be installed and propose the right cycle of materials and treatments, together with the documentation to hand over to the organiser.

Are you planning a set design or an installation for a space open to the public? Tell us about your project: we will reply within 24/48 hours with the right solution, safety included.