Flammability and combustibility are not synonyms. Flammability is a graded property describing how a material ignites and burns under a defined ignition source, reported as a rate, a time, an index or a class. Combustibility is a binary verdict from a furnace at 750 degrees Celsius. This guide sets out what each word claims, which standard proves which, how the A1 and A2 limits are built from furnace and calorimeter results, why a non-combustible core can still carry a combustible facing, where fire retardant fits as a third and separate term, and how to write a specification that a supplier can actually be held to.

A composite building material is tested three separate ways and no single certificate covers all three. Its components are tested for non-combustibility and calorific value, the product is classified for reaction to fire as a non-homogeneous item, and the assembly it forms is tested for fire resistance or facade propagation. This guide sets out the component route under ISO 1182 und ISO 1716, the product route through EN 13823 und EN ISO 11925-2, the heat release and smoke data that composites need, the assembly tests in EN 1364-1 und EN 1365-1, and the large-scale tests in ISO 9705-1 and NFPA 285. It closes with a test matrix by product type, five failure modes unique to composites, and a checklist to settle before booking a laboratory.

Fire resistance testing for concrete is less about combustibility than about whether an element keeps its load, its integrity and its insulation for the required period. Slabs and roofs go to EN 1365-2, columns to EN 1365-4, loadbearing walls to EN 1365-1, all read with EN 1363-1 on the ISO 834-1 curve. This guide covers the element routes, the deflection and insulation criteria that actually decide a classification, why explosive spalling removes cover in minutes, how polypropylene fibres and moisture control change the outcome, and why the 2023 edition of EN 1992-1-2 replaced the 2004 text that most project documents still cite.

An A1 fire classification means the product has been shown by test to make no measurable contribution to a fire: no sustained flaming in a 750 °C furnace and a gross calorific value at or below 2.0 MJ/kg. Both routes are required, which is why A2 exists for products that pass one but not the other. This guide sets out the exact A1 and A2 limits, explains the SBI step that decides A2, shows how A1 sits inside a full designation such as A1-s1,d0, compares the EN, GB 8624 and North American routes, and lists the five checks that catch a weak supplier certificate.

Cable insulation fire testing runs at two levels that are routinely confused. At compound level, a material is screened on oxygen index to ISO 4589-2, on halogen acid gas to IEC 60754-1 Und, for low-halogen claims, nach IEC 60754-3. At cable level, the finished construction is judged on flame propagation to IEC 60332-1-2 or on a bunched ladder to IEC 60332-3, and in Europe on heat release, smoke and acidity through the EN 13501-6:2018+A1:2022 class system. This guide separates the two levels, shows where PVC, XLPE, EPR and LSZH compounds realistically land, explains the a1 and a2 acidity sub-classes, and sets out what a compound supplier should actually declare.

To select a flammability tester for plastics, work backwards from the certificate rather than forwards from the catalogue. This guide maps each obligation — a UL yellow card, an IEC CB report, an appliance glow wire requirement, a formulation study — to the governing method and the apparatus it needs: Die 50 W horizontal and vertical cabinet for HB, V-0, V-1 und V-2; Die 500 W arrangement for 5VA and 5VB; glow wire for GWFI and GWIT; needle flame for small parts; oxygen index and cone calorimeter for development. It explains why specimen form and thickness decide the quotation, sets out the six items to settle before asking for a price, and gives an eight-point acceptance checklist for a new machine.

The difference between a fire retardant coating and a fire resistant coating is the question each one answers. A retardant coating limits how fast fire spreads over a surface and earns a reaction-to-fire class under EN 13501-1 or a flame spread index under ASTM E84. A resistant coating protects a structural element for a stated period and earns a fire resistance rating under EN 13501-2, ASTM E119 or UL 1709. This guide sets the two test regimes side by side, explains why an intumescent coating has no rating of its own and is specified through section factor, dry film thickness and period, covers EN 13381-8 versus EN 13381-4, and lists the five specification errors that produce disputes.