DBL 5399 Soiling and Cleaning Behavior of Interior Materials

The “DBL 5399 Contamination and Cleaning Behavior of Interior Materials” standard, developed by Daimler, the owner of the Mercedes-Benz brand, describes the requirements and test methods for evaluating the contamination (soiling/dirt retention) and cleaning behavior of materials and components used in vehicle interiors.

This standard is widely applied in the automotive industry, particularly for Mercedes-Benz and related brands (including commercial vehicles). It ensures that interior surfaces and materials maintain an acceptable appearance and functionality over time, even after exposure to typical contaminants and repeated cleaning.

The DBL 5399 standard applies primarily to interior hardware components and materials that are exposed to contamination during daily use. It covers:

• Textiles and coated textiles
• Leather and leather fiber sheets
• Plastics, elastomers and foils
• Plastic roll products and similar roll materials

This standard is particularly important for upholstery, seat covers, door panels, headliners, carpets, and other trim pieces in the passenger compartment. It is frequently referenced alongside related standards such as DBL 5404 (thermoplastics for interiors), where contamination/cleaning media and evaluation methods derived from the DBL 5399 standard are used in cosmetic resistance or maintenance product testing.

The DBL 5399 standard describes the following:

• Contamination tests: Artificial contamination using standardized contamination agents (e.g., simulating skin oils, cosmetics, food, dirt) applied via manual methods, Martindale abrasion, crockmeter rubbing, or Veslic (rubbing) procedures.
• Cleaning tests: Evaluating how well soiled material can be restored using approved cleaning agents and methods.
• Evaluation criteria: Visual changes, color fastness, staining, gloss changes, or other appearance alterations are typically graded according to grayscale or reference standards (e.g., DIN EN ISO 4628-1 standard for assessing deterioration).

Tests are typically carried out by accredited laboratories to verify that supplier materials meet Mercedes-Benz approval requirements.

In premium vehicles like Mercedes-Benz, interior durability and ease of maintenance are critical to customer satisfaction. The DBL 5399 standard helps ensure materials are resistant to common stains (such as coffee, makeup, and hand cream) and can be cleaned without damage, fading, or excessive wear.

This standard is part of the broader Daimler DBL delivery specifications system for automotive parts and materials.

In textiles (particularly in automotive contexts), cleanability resistance refers to a material's ability to withstand cleaning processes without experiencing unacceptable damage, change in appearance, or loss of performance characteristics. This measures how well a textile product (or coated fabric, leather) can be cleaned repeatedly using specific substances and methods while maintaining its original appearance, texture, color, strength, and other properties.

The key characteristics of cleanability resistance are as follows:

• Resistance to cleaning agents: The fabric should not fade, change color, bleed, crack, harden, lose its coating/adhesion, pill, or deteriorate when exposed to approved cleaners (e.g., mild soap solutions, specialized automotive interior cleaners, or sometimes stronger agents).
• Post-contamination restoration: This assesses whether stains or contamination (from skin oils, cosmetics, food, dirt) can be effectively removed through cleaning without leaving permanent marks or residue.
• No adverse side effects: Good cleanability resistance means that cleaning does not cause swelling, shrinkage, changes in gloss, fiber damage, or chemical reactions that damage the material.

These properties are different from (but related to) stain resistance (which relates to preventing stains from setting in the first place) or dirt repellency (how easily dirt adheres). A fabric may show good resistance to initial staining, but still have poor cleanability if attempts to remove ingrained dirt damage it.

In the Mercedes-Benz DBL 5399 standard, cleanability resistance is a fundamental requirement for interior textiles and materials. Tests simulate real-world soiling followed by standardized cleaning cycles. The material must pass visual inspections (e.g., using grayscale for color change/staining according to ISO standards) and sometimes other checks (e.g., no excessive changes in tactile feel or surface properties).

The DBL 5399 standard is considered essential because it directly addresses a critical aspect of long-term quality, customer satisfaction, and brand reputation in high-end vehicles. In luxury car interiors, materials (textiles, leather, plastics, coated fabrics) are constantly exposed to real-world contamination from daily use, such as hand creams, makeup, sunscreens, food spills, skin oils, dirt from hands/clothing, beverages, and general grime. Without standardized requirements for dirt-retention resistance and cleanability (how well stains can be removed without damaging the material), interiors in vehicles can quickly appear worn, stained, or deteriorated.

The main reasons why the DBL 5399 standard is indispensable are as follows:

• It retains its superior appearance over time.
• It provides durability and low maintenance.
• Supplier quality control and approval process
• It reduces warranty and after-sales costs.
• It supports brand differentiation.
• Cross-references are provided in other standards.

Consequently, high cleanability resistance means the fabric can be easily and safely maintained throughout the vehicle's lifespan without compromising its superior appearance or durability. This is exactly what luxury car manufacturers demand for seats, door panels, and other visible interior parts.

For many years, our organization, with its competent and experienced team, 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 compliant with the DBL 5399 standard.