Hohenstein Quality Label: "Medically Tested"

Materials can release cell-damaging substances when used. These toxics are detected on the sample material by analyzing their effect on skin cells. The cytotoxicity test (DIN EN) ISO 10993-5 is the first of several biocompatibility tests in the (DIN EN) ISO 10993 series of standards that we conduct.

For this test, an extract of the sample material is prepared and cultivated with L 929 skin cells in different concentrations over several days. The vitality of the cells or the potential cell-damaging effect of the test material is quantified in comparison to control cultures.

Required: the substances released from the sample have no cell-toxic effect. The quality label is issued based on a test report with detailed results.

This cell culture test uses immune cells to detect the allergy potential of substances that may be released from the sample material when used. The sensitization test is a general screening test for the detection of an allergenic effect. The technical prerequisite for the sensitization test is passing the cytotoxicity test.

For this test, an extract of the sample material is prepared and incubated with immune cells for 48 hours. Sensitizing substances stimulate the cells to form surface markers to which specific fluorescence-labeled antibodies are bound. In the flow cytometer, the percentage of positive cells is determined by the fluorescence intensity.

Required: no sensitization potential is detected by the sample. The quality label is issued based on a test report with detailed results.

Skin irritation is the property of a substance or material to cause reversible damage and destruction of the tissue after skin contact. In the in vitro test for skin irritation according to DIN EN ISO 10993-23, human three-dimensional skin models are used which, analogous to the human epidermis, are composed of different cell layers.

The samples/extracts are applied to the surface of the skin models and incubated overnight, then washed. The vitality of the applied skin cells is quantified in comparison to control cultures and allows an assessment of the irritant potential of the sample.

Required: the sample is assessed as non-irritating, i.e. it has a vitality of >50 % compared to the negative control. The quality label is based on a test report with detailed results.

The irritating effect of materials is quantified on the basis of changes to the mucous membrane of a chicken egg. The test assesses the hazard potential for skin irritation. The HET-CAM according to DB-ALM Method Summary n° 96 is a recognized alternative to the animal test on the rabbit eye (Draize test).

For this test, an extract of the sample material is prepared and placed on the chorionallantoic membrane (CAM) of incubated chicken eggs for a few minutes. Certain textiles or creams/ointments/solutions can be applied directly to the CAM. The strength of three different types of reaction of the CAM (coagulation, hemorrhage and lysis of blood vessels) is determined according to the endpoint method.

Required: no highly irritating substances are released from the test material (test result: "not irritating to slightly irritating, score ≤ 10). The quality label is issued based on a test report with detailed results.