Alcohol torch combustion performance testing service

Alcohol Torch Combustion Performance Testing Service – Accredited ISO/IEC 17025 Fire Resistance and Flammability Assessment for the Croatian Market

Alcohol torch combustion performance testing is a critical fire safety evaluation method used to assess the flammability, flame spread, self‑extinguishing behavior, and heat release characteristics of materials exposed to a controlled alcohol flame. This test is essential for ensuring the fire resistance and safety of products used in automotive, aerospace, construction, railway, marine, and consumer goods industries, where materials must meet strict fire safety regulations to protect lives and property. In the Croatian market, where the Hrvatski zavod za norme (HZN), the Ministarstvo gospodarstva i održivog razvoja, the Državni inspektorat, the Ministarstvo graditeljstva i prostornoga uređenja, and the Carinska uprava enforce stringent fire safety standards aligned with EU directives and HRN EN (Croatian standards based on European norms), the accurate evaluation of alcohol torch combustion performance is essential for product certification, supplier qualification, type testing, quality control in manufacturing, and import‑export processes. Our laboratory offers a comprehensive alcohol torch combustion performance testing service, applying standardized methods such as ASTM D635, ISO 9772, UL 94, IEC 60695-11-3, ASTM D5048, and HRN EN ISO 9772 to measure burning rate, after‑flame time, after‑glow time, and resistance to ignition under controlled alcohol flame conditions. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Croatian authorities and notified bodies, making them indispensable for regulatory compliance, product validation, and market access in Croatia and the European Union.

Materials and Products We Regularly Test

Our laboratory receives a wide variety of materials and products for alcohol torch combustion performance testing. Typical samples include:

• Plastics and polymers – thermoplastics, thermosets, and elastomers used in automotive interiors, electrical enclosures, and consumer goods.
• Textiles and upholstery – fabrics, carpets, and seat coverings for transportation and furniture applications.
• Electrical and electronic components – wire insulation, connectors, and printed circuit boards (PCBs).
• Composite materials – fiber‑reinforced plastics and laminates for aerospace, construction, and marine applications.
• Automotive and transportation components – interior panels, dashboards, headliners, and door trims.
• Building materials and finishes – wall panels, ceiling tiles, insulation materials, and flooring.
• Protective coatings and paints – fire‑retardant coatings and intumescent paints.
• Prototype and new material formulations – submitted by manufacturers for validation of combustion performance before series production.
• Field‑retrieved components – for failure analysis and remaining life assessment.

Horizontal Burning Test – Standard Method for Plastics and Materials

The horizontal burning test is the most widely used method for evaluating the combustion performance of materials under a controlled alcohol torch flame. The test measures the burning rate and the self‑extinguishing behavior of the material when exposed to a flame for a specified duration. Our procedures follow international standards and the requirements of the Croatian automotive, electrical, and construction sectors.

• Horizontal burning test (ASTM D635 / ISO 9772 / HRN EN ISO 9772 / NTC 5600 – for plastics and polymeric materials) – we mount a test specimen (typically 125 mm × 13 mm × 3 mm) horizontally in a test fixture. A small alcohol torch flame (with a specified flame height, e.g., 20 mm) is applied to one end of the specimen for a specified duration (e.g., 30 seconds). The flame is then removed, and the burning behavior is observed. We measure the burning time, the burned length, and the burning rate (in mm/min). We report the burning rate, the after‑flame time, the after‑glow time, and the pass/fail status (based on the specified criteria).
• Horizontal burning test for foams (ASTM D4986 / ISO 9772 – variant for cellular materials) – we perform the horizontal burning test on foam specimens (with a thickness of up to 25 mm). The test is similar to the standard method, but with a modified specimen size and a flame application time of 60 seconds. We report the burning rate and the after‑flame time.
• Horizontal burning test at different thicknesses (NTC 5601 – for the thickness effect) – we perform the horizontal burning test on specimens of different thicknesses (e.g., 1 mm, 3 mm, 6 mm) to evaluate the effect of the thickness on the burning behavior. We report the burning rate at each thickness.
• Horizontal burning test after aging (NTC 5602 – for the durability assessment) – we age the material (e.g., by thermal aging, UV exposure, or humidity) and then perform the horizontal burning test. The change in the burning rate and the after‑flame time are reported. We report the burning performance after aging and the retention of the fire resistance.
• Horizontal burning test with different flame application times (NTC 5603 – for the ignition sensitivity) – we vary the flame application time (e.g., 10 s, 30 s, 60 s, 120 s) to evaluate the ignition sensitivity and the resistance to sustained combustion. We report the burning behavior at each application time.

Vertical Burning Test – Standard Method for Electrical and Automotive Materials

The vertical burning test is a more severe test than the horizontal burning test, and it is used to evaluate the resistance of materials to flame propagation and dripping. The test is performed on a vertically mounted specimen, and the flame is applied to the bottom of the specimen. This method is widely used for materials used in electrical enclosures, wire insulation, and automotive interiors.

• Vertical burning test (UL 94 V / IEC 60695-11-10 / NTC 5610 – for plastics and electrical components) – we mount a test specimen (125 mm × 13 mm × 3 mm) vertically in a test fixture. A small alcohol torch flame (with a specified flame height, e.g., 20 mm) is applied to the bottom of the specimen for 10 seconds. The flame is then removed, and the after‑flame time is measured. The flame is reapplied for another 10 seconds, and the after‑flame time and the after‑glow time are measured. The specimen is classified as V‑0, V‑1, or V‑2 based on the after‑flame times and the occurrence of dripping. We report the UL 94 classification (V‑0, V‑1, V‑2, or fails).
• Vertical burning test for thin materials (UL 94 VTM / NTC 5611 – for thin films and sheets) – we perform a modified vertical burning test for thin materials (thickness < 0.5 mm) using a different specimen size (200 mm × 50 mm) and a different flame application method. The material is classified as VTM‑0, VTM‑1, or VTM‑2. We report the VTM classification.
• Vertical burning test with dripping (NTC 5612 – for the dripping assessment) – we evaluate the dripping behavior of the material during the vertical burning test. The occurrence of flaming droplets is recorded, and the material is classified accordingly. We report the dripping behavior and the pass/fail status.
• Vertical burning test at different temperatures (NTC 5613 – for the thermal effect) – we perform the vertical burning test at elevated temperatures (e.g., 40 °C, 60 °C) to evaluate the effect of temperature on the flammability. We report the UL 94 classification at each temperature.
• Vertical burning test after environmental exposure (NTC 5614 – for the durability assessment) – we age the material (e.g., by UV exposure, humidity, or thermal aging) and then perform the vertical burning test. We report the UL 94 classification after aging and the retention of the fire resistance.

Flame Spread and After‑Flame Time – Evaluating the Fire Propagation and Extinction

The flame spread and the after‑flame time are critical parameters that determine the fire safety of a material. Our tests measure the time required for the flame to spread across the specimen and the duration of the combustion after the flame is removed, providing essential data for the design of fire‑safe products.

• • Flame spread time measurement (NTC 5620 – for the propagation velocity) – during the horizontal burning test, we measure the time required for the flame front to travel a specified distance (e.g., 25 mm, 50 mm, or 75 mm). The flame spread rate (in mm/min) is calculated. We report the flame spread time and the flame spread rate.
  • After‑flame time measurement (NTC 5621 – for the self‑extinguishing behavior) – we measure the time (in seconds) that the specimen continues to burn after the flame is removed. A short after‑flame time indicates a good self‑extinguishing behavior. We report the after‑flame time and the pass/fail status.
  • After‑glow time measurement (NTC 5622 – for the glowing combustion) – we measure the time (in seconds) that the specimen continues to glow (without visible flames) after the flame is removed. A short after‑glow time indicates a low risk of re‑ignition. We report the after‑glow time.
  • Dripping and melt‑through behavior (NTC 5623 – for the melting and dripping assessment) – we observe the behavior of the material during the burning test, including the melting, the dripping, and the melt‑through. The dripping of flaming droplets is recorded. We report the dripping behavior and the melt‑through condition.
  • Flame spread and after‑flame time at different orientations (NTC 5624 – for the directional effect) – we perform the burning test at different orientations (e.g., horizontal, vertical, and at a 45° angle) to evaluate the effect of the orientation on the flame spread and the after‑flame time. We report the results for each orientation.

Ignition Resistance and Self‑Extinguishing – Evaluating the Fire Protection Effectiveness

The ignition resistance and the self‑extinguishing behavior are the most important parameters for fire‑safe materials. Our tests evaluate the ability of the material to resist ignition and to stop burning once the ignition source is removed, providing a direct measure of its fire protection effectiveness.

• Ignition resistance test (NTC 5630 – for the ignition time measurement) – we apply the alcohol torch flame to the specimen and measure the time required for the specimen to ignite (the ignition time, in seconds). A long ignition time indicates a good ignition resistance. We report the ignition time and the pass/fail status.
• Self‑extinguishing test (NTC 5631 – for the fire extinction capability) – we remove the flame after a specified application time (e.g., 30 seconds) and observe whether the specimen continues to burn. If the specimen self‑extinguishes within a specified time (e.g., 30 seconds), it is considered self‑extinguishing. We report the self‑extinguishing behavior and the after‑flame time.
• Self‑extinguishing test with repeated flame applications (NTC 5632 – for the cumulative damage) – we apply the flame to the specimen, allow it to self‑extinguish, and then re‑apply the flame at the same location (or at a different location) for a specified number of cycles (e.g., 5 cycles). The self‑extinguishing behavior and the cumulative damage are evaluated. We report the number of cycles and the condition of the specimen.
• Ignition resistance at different heat fluxes (NTC 5633 – for the thermal flux sensitivity) – we vary the flame intensity (the heat flux) by adjusting the flame height or the distance between the flame and the specimen. The ignition time and the self‑extinguishing behavior are measured at each heat flux. We report the ignition time and the self‑extinguishing behavior as a function of the heat flux.
• Ignition resistance after aging (NTC 5634 – for the durability assessment) – we age the material (e.g., by thermal aging, UV exposure, or humidity) and then perform the ignition resistance test. The change in the ignition time and the self‑extinguishing behavior are reported. We report the ignition resistance after aging and the retention of the fire protection.

Heat Release and Smoke Production – Evaluating the Fire Severity and Visibility

The heat release rate and the smoke production are critical parameters for assessing the fire severity and the visibility during a fire. Our tests measure the heat release rate (using a cone calorimeter) and the smoke density, providing a comprehensive assessment of the fire risk.

• Heat release rate measurement (ISO 5660‑1 / HRN EN ISO 5660‑1 / NTC 5640 – cone calorimeter method) – we expose a flat specimen (100 mm × 100 mm) to a controlled radiant heat flux (e.g., 50 kW/m²) in a cone calorimeter. We measure the heat release rate (HRR, in kW/m²), the total heat released (THR, in MJ/m²), and the time to ignition (in seconds). The heat release rate is a measure of the fire intensity. We report the HRR, the THR, the peak HRR, and the time to ignition.
• Smoke production measurement (ASTM E662 / ISO 5659‑2 / NTC 5641 – for the smoke density) – we expose the specimen to a radiant heat source (25 kW/m² or 50 kW/m²) in a smoke density chamber. The light transmittance through the smoke is measured, and the specific optical density (Ds) is calculated. We report the maximum Ds, the Ds at 1.5 min, 4 min, and 10 min, and the smoke production rate.
• Toxic gas emission measurement (ISO 19702 / NTC 5642 – for the gas analysis) – we use Fourier‑transform infrared (FTIR) spectroscopy or gas chromatography to analyze the combustion gases for toxic compounds (CO, CO₂, HCl, HCN, NOx, SO₂, etc.). The concentrations of the toxic gases are reported. We report the gas concentrations and the toxicity index.
• Heat release rate and smoke production at different heat fluxes (NTC 5643 – for the thermal flux sensitivity) – we perform the cone calorimeter test at multiple heat fluxes (e.g., 25 kW/m², 50 kW/m², 75 kW/m²) to evaluate the effect of the heat flux on the HRR and the smoke production. We report the HRR and the smoke production at each heat flux.
• Correlation between the alcohol torch test and the cone calorimeter results (NTC 5644 – for the method comparison) – we compare the results of the alcohol torch test (the burning rate, the after‑flame time) with the cone calorimeter results (the HRR, the THR) to establish a correlation between the two methods. We report the correlation and the predictive capability.

Environmental and Aging Effects – Evaluating the Long‑Term Fire Performance

The combustion performance of materials can change over time due to aging, environmental exposure, and wear. Our environmental and aging tests evaluate the long‑term stability of the fire performance, ensuring the reliability of the product over its service life in the diverse Croatian climate (coastal, continental, and mountainous).

• Thermal aging effect on combustion performance (ASTM D573 / ISO 188 / NTC 5650 – for the heat‑aged materials) – we age the material in an oven at a specified temperature (e.g., 70 °C, 100 °C) for a specified duration (e.g., 7, 14, or 28 days) and then perform the alcohol torch test. The change in the burning rate, the after‑flame time, and the UL 94 classification are reported. We report the combustion performance after aging and the retention of the fire resistance.
• UV and weathering effect (ASTM G154 / NTC 5651 – for the outdoor‑exposed materials) – we expose the material to UV radiation (UVA‑340) and condensation cycles for a specified duration (e.g., 500 hours) and then perform the alcohol torch test. The change in the combustion performance is reported. We report the combustion performance after UV exposure and the change.
• Humidity and water immersion effect (ASTM D570 / NTC 5652 – for the moisture‑exposed materials) – we condition the material at a high‑humidity environment (e.g., 40 °C, 95 % RH) or immerse it in water for a specified duration (e.g., 7 days) and then perform the alcohol torch test. The change in the combustion performance is reported. We report the combustion performance after humidity exposure and the moisture uptake.
• Chemical exposure effect (ASTM D543 / NTC 5653 – for the chemically exposed materials) – we immerse the material in various chemicals (e.g., mineral oil, 10 % HCl, 10 % NaOH, or a solvent) for a specified duration (e.g., 7 days) and then perform the alcohol torch test. The change in the combustion performance is reported. We report the combustion performance after chemical exposure and the compatibility.
• Abrasion and wear effect (NTC 5654 – for the surface‑damaged materials) – we subject the material to a specified number of abrasion cycles (e.g., using a Taber abraser) and then perform the alcohol torch test. The change in the combustion performance is reported. We report the combustion performance after abrasion and the wear depth.

Complementary Tests – Material Identification, Thickness, and Hardness for Fire Performance Correlation

To fully understand the combustion performance and to correlate it with the material's properties, we perform complementary tests, including material identification, thickness measurement, and hardness testing.

• Material identification (FTIR, DSC – NTC 5660 – for the polymer identification) – we use Fourier‑transform infrared spectroscopy (FTIR) to identify the chemical composition of the material (the polymer type, the additives, and the flame retardants) and differential scanning calorimetry (DSC) to measure the glass transition temperature (Tg). The chemical composition and the Tg are correlated with the combustion performance. We report the material identification and the Tg.
• Thickness measurement (NTC 5661 – for the specimen thickness) – we measure the thickness (in mm) of the material. The thickness is correlated with the burning rate and the UL 94 classification. We report the thickness and the correlation.
• Hardness testing (ASTM D2240 / NTC 5662 – Shore A or Shore D) – we measure the Shore A or Shore D hardness of the material. The hardness is correlated with the combustion performance (harder materials generally have a lower burning rate). We report the hardness and the correlation.
• Density measurement (ASTM D792 / NTC 5663 – for the material density) – we measure the density (in g/cm³) of the material. The density is correlated with the combustion performance and the heat release rate. We report the density and the correlation.
• Thermogravimetric analysis (TGA) – ASTM E1131 / NTC 5664 – for the thermal stability) – we use TGA to measure the thermal stability and the decomposition temperature of the material. The decomposition temperature is correlated with the ignition temperature and the burning rate. We report the decomposition temperature and the mass loss.

Test Report and Recognition in the Croatian Fire Safety, Automotive, and Construction Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (burning test apparatus, cone calorimeters, smoke density chambers, and analytical instruments) and traceability to international standards (NIST, PTB). Our test reports are issued in English (with a Croatian summary available on request) and include:

• Full identification of the test material (manufacturer, material type, dimensions, and intended application).
• Detailed description of the test methods applied (ASTM/ISO/UL/IEC/HRN EN/NTC standards, test conditions, and flame parameters).
• Numerical results: burning rate (mm/min), after‑flame time (s), after‑glow time (s), UL 94 classification (V‑0, V‑1, V‑2), flame spread rate (mm/min), heat release rate (kW/m²), smoke density (Ds), and ignition time (s).
• Graphical data: burning rate vs. time curves, HRR vs. time curves, and smoke density vs. time curves.
• Comparative tables against the values specified by the client or against the limits of the relevant standards (ASTM D635, ISO 9772, UL 94, IEC 60695-11-3, HRN EN ISO 9772, and the requirements of the HZN, Ministarstvo graditeljstva, and Državni inspektorat).
• Photographs of the test specimens before and after the test, showing the burned area and the dripping behavior.
• Recommendations for material selection, flame‑retardant formulation optimization, and quality control measures to achieve the required combustion performance.
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98‑3 Guide.

These reports are fully accepted by the Hrvatski zavod za norme (HZN) for the verification of product conformity, by the Ministarstvo gospodarstva i održivog razvoja for industrial and energy compliance, by the Državni inspektorat for market surveillance, by the Ministarstvo graditeljstva i prostornoga uređenja for building materials approval, and by the Carinska uprava (Croatian Customs) for tariff classification and quality verification in the import of materials and components. Additionally, we offer consulting services for the selection of flame‑retardant materials, the design of fire‑safe products, and the implementation of quality control programs for combustion performance, contributing to the fire safety, reliability, and regulatory compliance of products in the diverse and growing Croatian market, from the automotive and aerospace sectors to the construction, electrical, and consumer goods industries.