ISO 1182 tests whether a building product, exposed in a furnace at 750 °C, contributes appreciable heat or flame to a fire. It applies to the homogeneous products and substantial components that aim at the top of the classification systems - Euroclass A1 in EN 13501-1 and the equivalent grades in national systems such as GB 8624.
The criteria
Three quantities are judged: the temperature rise of the furnace and specimen (A1 uses a limit of 30 °C on furnace temperature rise in the EN 13501-1 criteria), the duration of sustained flaming (none beyond brief flaming for the top classes), and the mass loss of the specimen (a limit of 50% in the A1 criteria). The exact limits depend on the classification document applying the test, which is why the report records all three quantities plus the full temperature traces.
Why the furnace design matters
At 750 °C, furnace uniformity decides results. The furnace temperature distribution is checked with a dedicated calibration device - on the Motis NCF, a thermocouple calibration gauge and a 360-degree rotating scanner for wall temperature - and control is by PID with staged heating. Read the method alongside its A1 partner test, ISO 1716 on the bomb calorimeter: the furnace shows the product releases almost no heat in a fire; the bomb shows it stores almost no chemical energy. The NCF product page gives the furnace's documented specification.