Indicators are designed to be placed into a special holder that acts as process challenge device, where covered side represents complex instruments and hinges that are hard to clean. The WD-Chex polymer substrate is much closer to many instruments made with polymer components and better represent surfaces with cavities and rough finish. The WD-Chex Indicator consists of proteins, polysaccharides with black dye on fibrous non-cellulose substrate. ISO 15883-5 standard recommends using black color for washer-disinfector soils for greatest differentiation from background.
Protein stain does not have human or animal blood-derived components. There is no risk of contamination with blood-borne pathogens, BSE, CJD etc. Indicator substrate has a rough porous surface. It mimics medical soil on difficult-to-clean instruments with cavities and rough surfaces.
WD-Chex Indicator matches resistance requirements of ISO 15883-5 test soil