Mercedes-Benz DBL 5307 Flame Retardant Properties - Interior Trim Parts - Requirements and Test Specifications

The standard "Mercedes-Benz DBL 5307 Flame-retardant properties - Interior trim parts - Requirements and test specifications," published by the Mercedes-Benz Group, specifies the requirements for flame-retardant properties for interior components as well as for component parts, materials, and material systems adjacent to the interior. Exceptions are mineral glass and metals, as well as components that perform a specific electrical or electronic function. This standard also specifies test specifications.

In the table titled “Overview of available product versions”, product versions with flame retardant properties are listed according to national regulations, test specifications to be complied with and scope of application.

The general requirements in this standard are determined as follows:

• To ensure product safety and quality and to meet certification requirements, all relevant legal regulations and laws must be complied with. Furthermore, the relevant requirements of the Daimler Group apply.
• All materials, process engineering, component parts and systems must comply with all applicable legal requirements regarding components and recyclability.
• Must comply with the standard “DBL 8585 General requirements environmental protection, hazardous substances, negative substance list for hazardous goods material selection”.
• All interior components, materials, and material systems located in or around the passenger compartment should be checked.
• The current version of the legal provisions always applies.
• Daimler Group-specific specifications for emissions from materials and component parts in the vehicle interior must be adhered to and are contained in the DBL 5430 standard.
• Batch testing is often required for critical materials or material systems (e.g. textiles).
• For plastics used on Class A surfaces, a black color should preferably be tested. For plastics not in the field of view, a black or neutral color should preferably be tested.
• All components, materials, and material systems that abut Class A surfaces or Class A and B surfaces (e.g., seats) in the airspace of the vehicle interior must be tested for flame retardancy. Only components, materials, and material systems within a 13 mm offset of Class A or B surfaces must be tested.
• If the individual materials of the layers are not bonded across the entire surface in components and material systems (e.g., sewn, welded, glued at specific points, in strips, or in other linear patterns), they should be tested separately.

The Mercedes-Benz DBL 5307 standard establishes stringent requirements and test specifications for the flame retardancy of interior trim components used in vehicles. This standard ensures that materials used in the interiors of passenger cars, multi-purpose vehicles, trucks, and buses meet high safety standards to minimize fire risks and increase occupant safety.

The DBL 5307 standard applies to a wide range of interior materials and components used in Mercedes-Benz vehicles, including passenger cars, multi-purpose vehicles, commercial vehicles, and, in particular, buses with more than 22 seats. This standard covers materials such as:

• Seat components: Cushions, backrests, headrests and seat belts.
• Interior trims: Headliners, sun visors, door panels, side and rear panel trims and floor coverings.
• Functional materials: Materials with thermal or acoustic functions, such as heating and ventilation hoses, luggage racks and lighting systems.
• Special components: Textile tarpaulins, coated tarpaulins, nets for special vehicles (e.g. fire trucks, rescue vehicles) and curtains or roller blinds on buses.

This standard evaluates materials in various forms, including fiber materials, coatings, adhesives, foams, extruded materials, impregnations, leather, thermoplastics, thermosetting plastics, elastomers, and combinations thereof. It ensures that these materials inhibit fire formation or allow fire to spread very slowly, reducing the fire load inside the vehicle.

The DBL 5307 standard is divided into several subsections, each addressing specific aspects of flame retardant properties and test conditions. Briefly, these subsections are:

• DBL 5307.10 General interior materials: This section applies to all interior materials in passenger cars, multi-purpose vehicles, trucks, and buses. This includes components such as seat accessories, side and rear panel covers, floor coverings, luggage racks, heating and ventilation hoses, trim panels, and lighting systems. The focus is on ensuring that these materials meet basic flame retardant requirements.
• DBL 5307.11 Ageing due to thermal stress and humidity: This section addresses the risk of material incompatibility due to ageing caused by thermal stress. It evaluates how prolonged exposure to heat affects the flame retardant properties of interior materials.
• DBL 5307.12 Ageing due to thermal stress and humidity: This section expands the assessment to include the effects of humidity combined with thermal stress and considers how humidity affects material deterioration and flammability.
• DBL 5307.13 Ageing due to mild thermal stress: This section focuses on the flame retardant properties of materials subjected to mild thermal stress over time. This section ensures that materials maintain their fire-resistant properties even after prolonged exposure to low heat levels.
• DBL 5307.20 Bus ceiling trim: This section addresses interior trim materials used specifically for the ceilings of buses with more than 22 seats. It ensures that these materials meet flame retardant standards to improve passenger safety in larger vehicles.
• DBL 5307.21 Curtains and roller blinds: This section covers curtains and roller blinds used on buses with more than 22 seats and ensures that these components are flame retardant to prevent the spread of fire in passenger compartments.
• DBL 5307.22 Electrical conductors: This section specifies flame retardant requirements for electrical conductors on buses with more than 22 seats and ensures that wiring and related components do not cause a fire hazard.
• DBL 5307.40 Textile tarpaulins for special vehicles: This section applies to textile tarpaulins used on special vehicles such as fire trucks and rescue vehicles and provides flame retardant properties for these critical applications.
• DBL 5307.41 Textile tarpaulins for special vehicles: This section focuses on water treatment conditions for products defined in standard DBL 5307.40, particularly where ageing due to environmental factors may compromise flame retardant performance.
• DBL 5307.45 Coated tarpaulins and nets: This section addresses coated tarpaulins and nets used on special vehicles and ensures that these materials meet flame retardant standards in a variety of environmental conditions.
• DBL 5307-5.1 Horizontal burning rate test: A critical component of the standard, this section outlines testing for determining the horizontal burning rate of materials. This test evaluates how quickly a flame spreads across the surface of a material, ensuring it meets safety thresholds to minimize fire spread. This test is applicable to all interior trim materials in passenger cars, multi-purpose vehicles, commercial vehicles, and buses.

The DBL 5307 standard defines rigorous test methods for evaluating the flame retardant properties of materials. Key considerations include:

• Horizontal burning rate test (DBL 5307-5.1): This test measures the rate at which a flame spreads horizontally through a material sample. Materials must have a slow burning rate to meet the requirements of this standard.
• Ageing tests: Sections such as DBL 5307.11, DBL 5307.12 and DBL 5307.13 subject materials to thermal stress, moisture and light thermal stress to simulate ageing and assess whether their flame retardant properties are maintained over time.
• Composite testing: Materials that adhere to others at every point of contact are tested as a composite, while non-adherent materials are tested individually to ensure compatibility in all configurations.

Testing is typically performed by accredited laboratories, which are equipped to perform comprehensive evaluations in accordance with Mercedes-Benz factory standards.

The DBL 5307 standard plays a critical role in ensuring the safety of Mercedes-Benz vehicles by minimizing the risk of fire in the passenger compartment. By mandating stringent flame retardant requirements, the standard protects occupants by reducing the likelihood of rapid fire spread and ensuring materials maintain their fire-resistant properties under various environmental conditions. This is particularly crucial for buses and special vehicles, where passenger safety is paramount due to high passenger capacity or specialized use.

Our organization, which has been operating for many years and meticulously follows global developments in science and technology, employs a team of experienced professionals and a broad infrastructure to conduct testing, measurement, and analysis in a wide range of areas for businesses across all sectors. In this context, we also provide testing services in accordance with the "Mercedes-Benz DBL 5307 Flame retardant properties - Interior trim parts - Requirements and test specifications" standard.