Like all Mercedes-Benz model series, the S-Class carries the seal of the European Centre for Allergy Research Foundation (ECARF). The seal confirms that the values measured inside the vehicle meet the Foundation's stringent requirements, and that this has been confirmed in tests. A new testing procedure developed by Mercedes-Benz, for which a patent application has been filed, has shown that even the minutest of allergenic particles are trapped by the activated charcoal filter in the vehicle.
Allergies are now the most common form of chronic illness in industrialised countries. In Europe, around 30 percent of the population are affected. Not only airborne pollen from spring until autumn, but also emissions given off by materials, or skin contact with them, can lead to a strong immune reaction with symptoms such as swelling of the nasal passages and bronchial tubes or swollen, itching eyes.
Motorists with allergies can breathe a sigh of relief in a Mercedes-Benz car, as numerous interior components are tested for inhalation allergens before the vehicle goes into production. In addition, the pollen filter is tested for correct functioning in both the new and used condition.
Patent pending: Mercedes-Benz laboratory testing procedure
"For many years, we have been testing the efficiency of filters in air conditioners," explains Dr Andreas Wiegers, Design for Environment, Interior Emissions at Mercedes-Benz. "We design these filters so that, whether in fresh-air or air-recirculation mode, they allow virtually no particulate matter or pollen into the interior of the vehicle. The anti-allergenic effect of our filters in relation to pollen was scientifically confirmed many years ago. Unfortunately, it was previously impossible to measure especially small allergenic particles." The minutest particles include fragmented birch pollen, cat hair allergens and moulds. These are up to 1 µm in size, i.e. 50 to 100 times thinner than a human hair.
The experts at Mercedes-Benz therefore developed a sophisticated laboratory testing procedure, for which a patent application has been filed. The procedure uses a filtration apparatus with a vacuum suction flask. Small test particles are sucked into a flask through a tube. The flask contains a filter medium - an approx. 5 cm circular piece from the air conditioner filter. The solution is collected in a test tube at the bottom of the suction flask.
The efficiency of the filter is measured by means of a before/after comparison, with the concentration of allergens before and after the filter being determined. In tests with fungus spores, the Mercedes-Benz researchers formed a dilution series and counted the number of spores in a Petri dish. In the case of cat fur epitheliums and fine particles, the concentration of allergens was determined as the average outgoing quality in the ELISA test (Enzyme Linked Immunosorbent Assay). Depending on the concentration of allergens, the colour reaction of a liquid differs in intensity.
The outcome of the sophisticated laboratory tests is that the fine particle filter in Mercedes-Benz vehicles traps even the minutest of allergenic particles. The activated charcoal fine particle filter (standard in the S-Class, optionally available in many model series) offers optimal filtering of the outside and inside air; the activated charcoal also keeps odours out of the interior.
A medical study conducted by ECARF Institute GmbH with asthmatics as test subjects has confirmed the anti-allergenic effect of the filters. The tests were carried out using a section of the air conditioner from the current S-Class in the mobile pollen chamber in the grounds of the Charité university hospital in Berlin.