Determination of the fogging characteristics of trim materials in the interior of automobiles
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Determination of the fogging behavior of materials used in vehicle interiors
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Application for materials and components in vehicle interiors
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Two test methods: reflectometric and gravimetric method
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Simulation of realistic conditions through temperature exposure
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Evaluation of the release of volatile substances and condensation formation
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Important for material selection to minimize fogging problems
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Updated version with new example curves and specified tolerances
Content, scope of application and tests:
The DIN 75201 standard defines a test method for determining the fogging behavior of materials used in vehicle interiors. The scope of application includes various materials and components in vehicle interiors, in particular those that can potentially release volatile substances.
The phenomenon of “fogging” refers to the formation of a hazy film or condensation on interior surfaces of a vehicle, such as the windshield or windows, which can impair visibility and disrupt the driving experience.
The standard provides for two main test methods: the reflectometric method and the gravimetric method:
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In the reflectometric method, a sample material is placed in a beaker, covered with a glass plate and heated to 100°C for three hours. At the same time, the glass plate is cooled to 21°C, allowing gases from semi-volatile organic compounds (SVOC) to condense on the glass. The reflection index of the fogged plate is then calculated.
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The gravimetric method, on the other hand, uses a sheet of aluminum foil as a cover. The material is heated to 100°C for 16 hours while the aluminum sheet is kept at 21°C. After the test period, the amount of mist condensate collected is measured.
Specific sample quantities and sizes are prescribed for carrying out the tests.
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For the gravimetric method, two test specimens with a diameter of 8 cm each or 2 x 10 g of material are required.
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For the reflectometric method, four specimens with a diameter of 80 mm or 4 x 10 g each are required.
The test conditions simulate realistic scenarios that can lead to fogging. The materials are exposed to elevated temperatures to provoke the release of volatile substances. The standard specifies specific conditions and equipment for carrying out the test in order to enable a standardized and comparable evaluation.
During the evaluation, particular attention is paid to the quantity and type of condensed substances. In the case of the reflectometric method, the reflectance index of the fogged glass plate is measured, while in the gravimetric method the weight increase of the aluminum foil is determined.
The documentation of the test results is an important part of the procedure. The updated version of the standard includes revised requirements for test reports to ensure standardized and comprehensive reporting.
The DIN 75201 standard was recently updated, adding new example curves and more specific tolerances for temperature levels. These additions improve the comparability of the tests and enable a more accurate evaluation of the test results. In addition, the cleaning procedure for glass panes has been revised and changes have been made to borosilicate glass panes and reference compounds.
The application of this standard is particularly important for the automotive industry as it enables manufacturers and suppliers to make informed decisions when selecting materials and minimize potential fogging problems in vehicle interiors4. The DIN 75201 test methods are applied not only to finished materials, but also to liquid, paste, powder and solid raw materials from which these materials are manufactured.
Alternative standards:
- VDA 278:2011-09 - Thermal desorption analysis of organic emissions for the characterization of non-metallic automotive materials
- VDA 275:1994-06 - Molded parts for vehicle interiors - Determination of formaldehyde emission
- DIN EN 60068-2-14 - Test methods for appliances and components at variable temperatures