- If it's green, it's clean
The 3M™ Clean-Trace™ Surface Protein Plus Hygiene Test is simple and effective. It detects protein and reducing agents left behind on surfaces after inadequate cleaning. Food residues remaining on the surface provide nutrients for bacterial growth that could lead to product contamination. Simply swab the surface, click down the handle fully into the tube and shake for 5 seconds. Results are visual and easy to interpret, if it's green it's clean, if it turns purple it's contaminated. The faster the test turns purple the higher the level of contamination on a surface.