Research demonstrates that certain lights have antimicrobial properties. Violet-blue light at 405 nm (VBL405) has a broad-spectrum effect on organisms that frequently cause hospital-acquired infections including Clostridium difficile, Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, and various Mycobacterium.