GMW 15635 Determination of Aldehyde and Ketone Emissions from Interior Materials

The “GMW 15635 Determination of aldehyde and ketone emissions from interior materials” standard, developed by General Motors Worldwide (GMW), is a test procedure used to determine aldehyde and ketone emissions from vehicle interior materials. This standard primarily addresses chemical emissions that may be released from non-metallic materials used in vehicles and helps manufacturers control interior air quality and meet material performance requirements.

GMW 15635 standard is also described as a replacement for GME 60271 standard and is particularly important to General Motors for interior material qualification.

This standard measures aldehyde and ketone emissions, including carbonyl compounds, released from interior vehicle materials. Examples of materials that can be evaluated include:

• Plastics and polymeric materials
• Coated textiles
• Leather and leather-related materials
• Fibers and textiles
• Functional coatings and composites
• Other non-metallic interior materials

Test laboratories list this method for applications involving compounds such as formaldehyde and acetaldehyde.

The GMW 15635 standard uses a controlled sealed flask emission method. Generally, a prepared test sample is placed on top of deionized water inside a sealed flask. The flask containing the sample is then exposed to a controlled temperature for a specific period of time. During this conditioning period, aldehydes and ketones released from the material are absorbed by the water. After exposure, the flask is cooled, and the absorbed compounds are chemically analyzed.

The analytical procedure uses the following:

• Derivatization of 2,4-Dinitrophenylhydrazine (DNPH)
• Converting carbonyl compounds into measurable derivatives.
• High performance liquid chromatography (HPLC)
• Ultraviolet (UV) detection

The amount obtained is typically reported in micrograms/gram (µg/g), based on the dry mass of the test sample.

Essentially, this method follows these steps:

• Sample preparation: Representative samples are prepared from the internal material.
• Conditioning and storage: Samples are protected from contamination and, if testing cannot begin immediately, are stored under controlled conditions. One current version of the procedure specifies cool, airtight storage with minimum air volume and limits storage time.
• Bottle preparation: The sample is placed on top of a quantity of deionized water inside a sealed bottle.
• Thermal exposure: The sealed bottle is placed in an oven for the specified test duration. Approximately 3 hours of oven exposure is followed by approximately 1 hour of cooling.
• Absorption: The diffused aldehydes and ketones are captured by deionized water.
• Chemical derivatization: 2,4-Dinitrophenylhydrazine (DNPH) is used to derivatize carbonyl compounds.
• HPLC analysis: Derivatives are analyzed using HPLC with a UV detector.
• Calculation and reporting: Measured concentrations are converted into emission values ​​based on the dry mass of the sample and expressed in µg/g.

GMW 15635 standard is considered important for the following reasons:

• Interior air quality: Vehicle occupants are surrounded by interior materials for extended periods. These materials can release chemicals into the cabin, especially when exposed to high temperatures. Measuring aldehydes and ketones helps identify materials that may contribute to deteriorating interior air quality.
• Material selection: This procedure provides engineers with a quantitative way to compare different materials, formulations, coatings, adhesives, and manufacturing processes.
• Product development: During vehicle development, emissions testing can help identify high-emission materials before they are incorporated into production components.
• Supplier quality control: Automotive suppliers can use this procedure to verify that materials consistently meet relevant General Motors requirements.
• Reducing unwanted emissions: Controlling carbonyl emissions can contribute to improving cabin air quality and reducing chemical exposure for vehicle occupants.

The GMW 15635 standard is part of a broader family of automotive interior emissions and air quality tests. Other manufacturers and organizations use related procedures for formaldehyde, volatile organic compounds, carbonyl compounds, odor, and fuzz. For example, laboratories list the GMW 15635 standard alongside the Ford FLTM BZ 156-01 standard, which addresses formaldehyde, aldehyde, and ketone emissions from non-metallic interior floor mats. However, these procedures are not automatically interchangeable. Even if the two methods measure similar chemicals, sample preparation, exposure conditions, collection method, analytical technique, and reporting requirements may differ.

The primary result is the amount of aldehydes and ketones released by the material, normalized to the dry weight of the test sample. Therefore, the method provides quantitative information rather than just a visual or sensory assessment. Typical reporting may include:

• Test sample identification
• Material description
• Test conditions
• Individual aldehyde concentrations
• Individual ketone concentrations
• Analytical results
• Valid evaluation or acceptance criteria

Actual acceptance limits are determined by the relevant General Motors material specification, drawing, or engineering requirement, rather than assuming a universal limit from the test procedure itself.

The GMW 15635 standard test method is particularly applicable to components such as the following:

• Dashboard materials
• Door trim materials
• Upholstery materials
• Ceiling flooring materials
• Flooring and carpet materials
• Plastic interior components
• Coated fabrics
• Polymer-based components
• Materials containing adhesives or coatings

Because different materials can have different chemical emission properties, this method provides a way to control emissions throughout the vehicle interior supply chain.

In conclusion, the GMW 15635 standard includes a crucial test procedure for evaluating carbonyl emissions from automotive interior materials. The described method utilizes a sealed-bottle exposure system where the released compounds are absorbed into deionized water, followed by DNPH derivatization and HPLC-UV analysis. Results are expressed as a percentage of the dry mass of the test material.

This standard supports indoor air quality control, material selection, supplier qualification, product development, and emission reduction. It is also the successor to the GME 60271 standard and remains part of the broader automotive indoor emissions testing environment. However, for laboratory work, the latest version of this standard should always be consulted for complete sample sizes, quantities, temperatures, exposure times, analytical conditions, calculations, and acceptance requirements.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the GMW 15635 standard.