Figure 4.

(A), Diagram of method B′ of the ISO 846 standard. In this method, the PUR sample is placed on the agar nutrient medium containing a carbon source when it is completely covered by mycelium. The test was performed in a 90 mm diameter Petri dish. (B), Growth of Aspergillus niger on polyether urethane after 9 weeks of contact according to the method described in A The magnification was obtained with a stereomicroscope. (C), scanning electron microscope views of a PUR coupon incubated on an agar medium containing no carbon source (left picture) and of a coupon of the same material incubated under the same conditions in the presence of A. niger (right picture).