Ozon Testi — ISO 1431-1 / ASTM D1149

What Is Ozone?

The ozone test is one in which an elastomer sample under strain is exposed to a defined ozone concentration to assess surface cracking. Ozone causes rapid surface cracking in rubbers containing double bonds.

Purpose of Ozone

The purpose is to determine the cracking resistance of rubber gaskets, hoses and profiles against atmospheric ozone, and to verify the effectiveness of antiozonant additives.

Which Products Is Ozone Applied To?

Rubber gaskets and seals
Hose and pipe elements
Automotive rubber profiles
Belts and vibration mounts

In Which Sectors Is Ozone Used?

ElectronicsElectricalAutomotiveDefenceAerospace

Standards Related to Ozone

ISO 1431-1
ISO 1431-3
ASTM D1149
ASTM D518

Ozone Conditions

Ozon konsantrasyonu: Defined in the standard; typically 25 – 200 pphm
Temperature: Defined in the standard; typically 30 or 40 °C
Gerinim: The sample is held at a defined percent elongation (e.g. 20%)
Time: Defined in the specification; typically 24, 48, 72 or 96 hours

Equipment for Ozone

Ozone test chamber and ozone generator
Ozone concentration measurement
Strain application frames
Magnifier-assisted inspection rig

Sample Requirements for Ozone

The sample must be cut in strip or ring form per the standard
Samples must be mounted on frames at the defined strain
A rest period must be applied before the test
Generally at least three specimens per set

Duration of Ozone

Typically one to four days depending on the specification.

Ozone Procedure

1Samples are cut and mounted on frames at the defined strain.
2Rested for the duration defined in the standard.
3Chamber ozone concentration and temperature are set and verified.
4Specimens are placed in the chamber.
5Exposure is maintained for the defined duration.
6The surface is examined under magnification and cracks are graded.

Ozone Acceptance Criteria

The acceptance criterion is defined in the specification: no visible cracks after the defined period or the degree of cracking does not exceed the specified limit.

Evaluation of Results

Cracks are assessed for number and size per the standard's grading scale. Strain level strongly affects the result and is stated in the report.

Ozone Report

Standard applied
Ozone concentration, temperature and strain
Exposure duration
Crack grading and photographs

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Rubber product specifications
Automotive OEM elastomer standards

Environmental and Climatic Testing — What Does This Testing Field Cover?

The section below describes the field that the Ozone test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Environmental testing shows whether a product withstands ambient factors such as temperature, humidity, pressure, solar radiation, dust, water and corrosive atmospheres. The aim is not to break the product but to bring forward, in ACCELERATED form, the conditions it will meet over its life.

Test profiles are derived from the product's real exposure, and that derivation is the actual engineering work of the field. A device operating in an enclosed office and one mounted on a pole are not tested with the same profile. The IEC 60068 series defines general methods, MIL-STD-810 military profiles, RTCA DO-160 aviation profiles and the ISO 16750 series location-based automotive profiles. A test applied without a profile selection produces both unnecessary cost and false confidence.

Temperature tests simulate three separate phenomena and all three produce different failure modes. Steady high/low temperature tests whether the material can operate at that temperature. Temperature CYCLING creates fatigue at joints between materials with different expansion coefficients — solder cracks appear here. Thermal SHOCK intensifies this effect through an abrupt transition.

There is a distinction in humidity testing too. Steady damp heat shows the diffusion of moisture into the material and its effect on insulation properties. Cyclic damp heat creates condensation: water droplets form on the cooling surface, and this is far more aggressive than dry humidity. Water ingress into enclosures, increased leakage current and corrosion usually appear in the cyclic test.

Dust and water protection is a separate body of work and is expressed by the IP code. The point to note here is that an IP test is not a DURABILITY test: it shows that protection is provided under defined and short-duration conditions, not resistance to long-term immersion or pressure washing.

The most common mistake in this family is translating a test result directly into a LIFE PREDICTION. Accelerated tests are designed for comparison and design verification; a reliable conversion between hours in a chamber and years in the field can only be established with a material-specific acceleration model calibrated against field data.

Functional monitoring determines the value of the test. Keeping a product in a temperature chamber and then switching it on does not show what happened DURING the test. In critical applications the product is operated throughout the test and its parameters are monitored; intermittent faults that appear and disappear can only be caught this way.

Method groups in this field

Temperature
Dry heat, cold, change of temperature and thermal shock; steady and cyclic profiles.
Humidity
Steady damp heat and cyclic damp heat; cycles with condensation are more aggressive.
Water and dust
IP protection tests: dripping, spraying, jets, immersion and dust tightness.
Radiation and ageing
Accelerated ageing by xenon arc and fluorescent UV, solar radiation simulation.
Pressure and altitude
Low pressure (altitude) and rapid pressure change tests.
Corrosive atmosphere
Salt spray, mixed flowing gas corrosion (simulating industrial atmospheres), mould and fungus tests.

Commonly confused in this field

Test duration cannot be converted into field life; a conversion made without an acceleration model is misleading.
Temperature cycling and steady temperature produce different failure modes; neither replaces the other.
If the product is not operated during the test, intermittent faults remain invisible; functional monitoring determines the value of the test.
IP protection is not evidence of durability; it shows protection under defined and short-duration conditions.
A test applied without profile selection both increases cost and gives false confidence.
The mounting and orientation arrangement affects the result; the report must document it.

Which decisions these results support

Design verification and qualification
Declaration of the protection class and operating temperature range
Reproducing field failures in the laboratory and root cause analysis
Supplier component approval
Decisions on warranty period and storage conditions

Related Tests

Frequently Asked Questions About Ozone

According to which standard is Ozone made?

Ozone is executed in scope ISO 1431-1, ISO 1431-3, ASTM D1149 and ASTM D518. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.

Which products does Ozone apply to?

Mainly applied to Rubber gaskets and seals, Hose and pipe elements, Automotive rubber profiles and Belts and vibration mounts. Whether your product is included in the scope is determined by examining its technical specifications and intended use.

Under what conditions is Ozone done?

The determining parameters are: Ozon konsantrasyonu — Defined in the standard; typically 25 – 200 pphm, Temperature — Defined in the standard; typically 30 or 40 °C and Gerinim — The sample is held at a defined percent elongation (e.g. 20%). The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.

What kind of sample is needed for Ozone?

The sample must be cut in strip or ring form per the standard, Samples must be mounted on frames at the defined strain and A rest period must be applied before the test. The number of samples is determined according to the product standard and the scope to be reported.

How long does Ozone take?

Typically one to four days depending on the specification. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.

What is the Ozone result called "appropriate"?

The acceptance criterion is defined in the specification: no visible cracks after the defined period or the degree of cracking does not exceed the specified limit.