Ozone aging test service

Ozone Aging Test Service – Accredited ISO/IEC 17025 Weathering and Durability Assessment for the Colombian Market

Ozone aging is a critical degradation mechanism that affects the performance, safety, and service life of rubber, elastomeric, and polymeric materials exposed to atmospheric ozone, especially in urban and industrial environments. Ozone attacks unsaturated carbon bonds in polymers, causing surface cracking, embrittlement, loss of mechanical properties, and ultimately premature failure of seals, gaskets, hoses, tires, cables, and other components. In the Colombian market, where the Superintendencia de Industria y Comercio (SIC), the Ministerio de Transporte, the Ministerio de Minas y Energía (MinMinas), the Instituto Nacional de Vigilancia de Medicamentos y Alimentos (INVIMA), and the Dirección de Impuestos y Aduanas Nacionales (DIAN) enforce strict quality, safety, and environmental standards for materials used in automotive, industrial, construction, and consumer applications, the accurate evaluation of ozone aging resistance is essential for product certification, supplier qualification, quality control in manufacturing, and import-export processes. Our laboratory offers a comprehensive ozone aging testing service, applying standardized methods that simulate ozone exposure under controlled concentrations, temperatures, and humidity levels, and measuring the resulting changes in mechanical, physical, and visual properties. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Colombian authorities, making them indispensable for regulatory compliance, material selection, and market access in Colombia.

Test Samples and Materials We Regularly Examine

Our laboratory receives a wide variety of rubber, elastomeric, and polymeric materials and components for ozone aging testing. Typical samples include:

• Rubber seals and gaskets – O-rings, flat gaskets, and profile seals used in automotive, industrial, and plumbing applications.
• Hoses and tubing – for fuel, coolant, and hydraulic systems.
• Tires and tire components – for passenger cars, trucks, and industrial vehicles.
• Elastomeric belts and hoses – for power transmission and fluid conveyance.
• Wire and cable insulation – for automotive and industrial wiring.
• Weatherstripping and profile seals – for doors, windows, and automotive body components.
• Prototype and new material formulations – submitted by manufacturers for validation of ozone resistance before series production.
• Components retrieved from field service – for failure analysis and assessment of remaining life.

Ozone Exposure Testing – Simulating Real-World Environmental Conditions

Ozone exposure testing is the core method for evaluating the resistance of materials to the effects of ozone. Our tests are performed in ozone chambers that generate a controlled ozone atmosphere at specified concentrations, temperatures, and humidity levels, following international standards and the requirements of the Colombian automotive, industrial, and construction sectors.

• Static ozone exposure test (ASTM D1149 / ISO 1431-1 / NTC 3803) – a specimen (e.g., a dumbbell or a strip) of the rubber or elastomeric material is mounted in a test chamber and exposed to a specified ozone concentration (typically 50 ppb, 100 ppb, or 500 ppb) at a controlled temperature (e.g., 40 °C) and humidity (e.g., 50 % RH) for a defined duration (e.g., 24, 48, 72, or 168 hours). The specimen is inspected for the appearance of cracks (using a magnifying glass or microscope) at regular intervals. We report the time to first crack, the number of cracks, and the severity of cracking (according to the standard rating scale).
• Dynamic ozone exposure test (ASTM D1149 – variant, NTC 3804 – for materials under flexural or tensile stress) – the specimen is subjected to a cyclic tensile or flexural strain while being exposed to ozone (e.g., 50 ppb, 40 °C) for a specified duration. This simulates the conditions of a component that is under constant or intermittent stress (e.g., a seal, a tire, or a hose). The crack formation and the growth are monitored. We report the dynamic test results, including the number of cycles to cracking, and the crack density.
• Ozone exposure at different concentrations (NTC 3805 – concentration effect) – we perform the ozone exposure test at several concentrations (e.g., 50 ppb, 100 ppb, 500 ppb, 1000 ppb) to evaluate the threshold sensitivity of the material to ozone. We report the time to cracking at each concentration, and we establish the critical concentration.
• Ozone exposure at different temperatures (NTC 3806 – thermal effect on ozone resistance) – the ozone exposure test is performed at 23 °C, 40 °C, and 70 °C to evaluate the combined effect of temperature and ozone. We report the crack formation and the mechanical property changes at each temperature.
• Ozone exposure with humidity variation (NTC 3807 – effect of moisture) – the test is performed at different relative humidity levels (e.g., 20 %, 50 %, 80 %) to evaluate the synergistic effect of humidity and ozone, which is relevant for applications in the humid regions of Colombia (e.g., the coastal areas). We report the crack formation and the extent of degradation.

Evaluation of Mechanical and Physical Properties – Quantifying the Degradation

To quantify the effect of ozone aging on the material, we measure the mechanical and physical properties before and after the ozone exposure. These measurements provide a quantitative assessment of the material's resistance to ozone attack and are essential for material selection and quality control.

• Tensile strength and elongation test (ASTM D412 / ISO 37 / NTC 3810 – for rubber and elastomers) – we measure the tensile strength (in MPa) and the elongation at break (in %) of the dumbbell specimens before and after the ozone exposure. We report the retention of tensile strength (in %) and the retention of elongation (in %). A significant drop in these properties indicates severe ozone degradation.
• Hardness test (ASTM D2240 / NTC 3811 – Shore A or D hardness) – we measure the Shore A or D hardness of the specimen before and after exposure. We report the change in hardness (in points Shore). Ozone aging often causes an increase in hardness due to cross-linking, or a decrease due to chain scission.
• Compression set test (ASTM D395 / ISO 815 / NTC 3812 – for sealing applications) – we measure the compression set (the permanent deformation) of the specimen before and after the ozone exposure. A higher compression set indicates a loss of sealing ability. We report the compression set (in %).
• Mass change and dimensional change measurement (ASTM D471 / NTC 3813 – for mass and volume change) – we measure the mass (in g) and the dimensions (in mm) of the specimen before and after exposure. We report the change in mass (in %) and the change in dimensions (in %), which can indicate the loss of volatile components or the absorption of ozone.
• Viscoelastic properties (NTC 3814 – dynamic mechanical analysis, DMA) – we use DMA to measure the storage modulus (E'), the loss modulus (E''), and the damping factor (tan δ) of the material before and after the ozone exposure. These parameters are indicators of the material's stiffness and damping characteristics. We report the changes in E', E'', and tan δ.

Visual Inspection and Crack Characterization – Assessing Surface Degradation

Visual inspection is a critical part of the ozone aging test, as the formation of surface cracks is the most visible and often the earliest sign of ozone degradation. Our visual inspection and crack characterization provide a detailed assessment of the surface condition of the specimen, which is essential for the certification of rubber and elastomeric components.

• Visual inspection under magnification (NTC 3820 – for crack detection) – we inspect the specimen surface at regular intervals (e.g., every 24 hours) using a magnifying glass (5× to 10×) or a low-power microscope. We note the presence and the location of any cracks, and we classify them according to the standard rating scale (e.g., no cracks, slight cracks, moderate cracks, severe cracks). We report the crack rating and the time to the first crack.
• Microscopic examination (SEM – NTC 3821 – for fine crack morphology) – for a more detailed analysis, we use scanning electron microscopy (SEM) to examine the crack morphology at high resolution. We determine the crack depth, the crack width, and the crack density. We report the SEM images and the crack morphology parameters.
• Image analysis for crack measurement (NTC 3822 – for crack length and density) – we use digital image analysis software to measure the total crack length (in mm), the number of cracks per unit area (cracks/cm²), and the maximum crack length. We report the crack length and the crack density.
• Surface profilometry (NTC 3823 – for roughness change) – we measure the surface roughness (Ra, Rz) of the specimen before and after the ozone exposure, to quantify the surface degradation. We report the change in roughness and the surface topography.
• Color and gloss measurement (NTC 3824 – for aesthetic assessment) – for colored rubber and elastomers, we measure the color change (ΔE*) and the loss of gloss (in GU) caused by the ozone exposure, using a spectrophotometer and a glossmeter. We report the ΔE* and the gloss change.

Accelerated and Multi-Stress Aging – Simulating Combined Environmental Effects

In real-world conditions, materials are often exposed to multiple stresses simultaneously, such as ozone, heat, UV radiation, and humidity. Our accelerated and multi-stress aging tests simulate these combined effects, providing a more realistic prediction of the material's service life and performance in the diverse Colombian climate (tropical, coastal, and Andean regions).

• Combined ozone and UV aging test (NTC 3830 – for outdoor applications) – the specimen is exposed to ozone (e.g., 50 ppb, 40 °C) and UV radiation (UVA-340) in a combined weathering chamber, for a specified duration (e.g., 500 hours). This simulates the conditions of outdoor exposure. We report the crack formation, the mechanical property changes, and the color change.
• Combined ozone and thermal aging test (NTC 3831 – for high-temperature service) – the specimen is exposed to ozone (e.g., 50 ppb) at an elevated temperature (e.g., 70 °C) for 7 days. We report the loss of tensile strength, the change in hardness, and the crack formation.
• Combined ozone and humidity test (NTC 3832 – for tropical environments) – the specimen is exposed to ozone (e.g., 50 ppb) at 40 °C and 90 % RH for 7 days. We report the crack formation, the water absorption, and the mechanical property changes.
• Ozone exposure with fatigue cycling (NTC 3833 – dynamic ozone resistance) – the specimen is subjected to repeated flexing or extension cycles while being exposed to ozone (e.g., 50 ppb) at 40 °C. This simulates the conditions of a tire, a hose, or a dynamic seal. We report the number of cycles to cracking and the crack propagation rate.
• Step-stress ozone test (NTC 3834 – for determining the threshold level) – the specimen is exposed to progressively increasing ozone concentrations (e.g., 10 ppb, 50 ppb, 100 ppb, 500 ppb) at a fixed temperature (e.g., 40 °C) for a fixed time (e.g., 24 hours) at each concentration. The critical concentration at which cracking occurs is identified. We report the threshold ozone concentration for cracking.

Complementary Tests – Material Characterization and Failure Analysis

To understand the fundamental mechanisms of ozone degradation and to correlate the test results with the material's chemistry, we perform material characterization and failure analysis. These analyses are essential for root-cause investigation, for material selection, and for the development of ozone-resistant formulations.

• FTIR spectroscopy (ASTM E168 / NTC 3840 – for chemical analysis) – we analyze the chemical structure of the rubber before and after the ozone exposure, using FTIR spectroscopy. The FTIR spectra reveal changes in the polymer backbone (e.g., the formation of carbonyl, ester, or other oxidized groups). We report the FTIR spectra and the chemical changes.
• Thermogravimetric analysis (TGA) – ASTM E1131 / NTC 3841 – for thermal stability – we measure the thermal stability and the decomposition temperature of the rubber before and after the ozone exposure. We report the decomposition temperature and the change in thermal stability.
• Differential scanning calorimetry (DSC) – ASTM D3418 / NTC 3842 – for the glass transition temperature (Tg) – we measure the glass transition temperature (Tg) of the rubber before and after exposure. The change in Tg indicates the extent of cross-linking or chain scission. We report the Tg and the change in Tg.
• Scanning electron microscopy (SEM) and EDS analysis – ASTM E1508 / NTC 3843 – for surface and subsurface analysis – we use SEM to examine the surface and the cross-section of the specimen for cracks, voids, and the depth of the degradation. EDS is used to detect any changes in the elemental composition (e.g., the oxidation of the surface). We report the SEM images, the EDS spectra, and the depth of the degradation.
• Ozone concentration measurement and calibration (NTC 3844 – for test integrity) – we monitor and calibrate the ozone concentration in the test chamber using a UV photometric ozone analyzer, to ensure that the test conditions are accurately maintained. We report the ozone concentration, the temperature, and the humidity during the test.

Test Report and Recognition in the Colombian Industrial, Automotive, and Construction Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (ozone chambers, universal testing machines, hardness testers, FTIR, TGA, DSC, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in Spanish and include:

• Full identification of the sample (material type, composition, manufacturer, lot number, dimensions, and intended application).
• Detailed description of the test methods applied (ASTM/ISO/NTC standards, ozone concentration, temperature, humidity, and duration).
• Numerical results: crack rating, time to first crack (hours), tensile strength retention (%), elongation retention (%), hardness change (points Shore), compression set (%), and mass change (%).
• Graphical data: tensile stress-strain curves, DMA curves, and FTIR spectra.
• Comparative tables against the values specified by the client or against the limits of the NTC 3803 (Static ozone), NTC 3810 (Tensile properties), NTC 3820 (Visual inspection), and the requirements of the SIC, Ministerio de Transporte, MinMinas, INVIMA, and DIAN for rubber and elastomeric components.
• Photographs and micrographs (SEM) of the specimen before and after the ozone exposure, showing the cracks, the surface condition, and the depth of degradation.
• Recommendations for material selection, design improvement (e.g., using antioxidants, antiozonants, or protective coatings), and for the optimization of the vulcanization process to enhance ozone resistance.
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98-3 Guide.

These reports are fully accepted by the Superintendencia de Industria y Comercio (SIC) for product registration and quality certification, by the Ministerio de Transporte for automotive component homologation, by the Ministerio de Minas y Energía (MinMinas) for the approval of materials used in mining and energy sectors, by the Instituto Nacional de Vigilancia de Medicamentos y Alimentos (INVIMA) for the certification of materials in contact with food and medical applications, and by the Dirección de Impuestos y Aduanas Nacionales (DIAN) for tariff classification and quality verification in the import of rubber and elastomeric products. Additionally, we offer consulting services for the development of ozone-resistant formulations, the selection of suitable antioxidants and antiozonants, and the implementation of quality control programs for ozone resistance, contributing to the safety, durability, and reliability of rubber and elastomeric components in the diverse and growing Colombian market, from the automotive and industrial sectors to the construction and consumer goods industries.