Effectiveness of HINS Light (405 nm) for Environmental Decontamination in Healthcare Settings
1. Clinical Setting Applications
Evidence from healthcare settings, including an isolation room in a burns unit and an ICU, demonstrated that HINS light effectively reduced environmental contamination.
In a comparative study between inpatient and outpatient settings, the outpatient room initially had lower contamination levels, but significant reductions were still observed with HINS light use.
Unoccupied rooms maintained low contamination even after the light was turned off. However, in occupied rooms, contamination levels returned to baseline once the light was deactivated.
Prolonged exposure enhanced the bactericidal effect of HINS light.
2. Effect of Distance and Installation Location
A hospital-based before-and-after study (Level 3 evidence) found that while the greatest reduction in bacterial load occurred closest to the HINS light source, significant reductions were also seen in areas farther away.
This suggests that installation position may not be critical, and airborne bacteria reduction plays an important role in its overall effectiveness.
3. Safety in Patient Environments
A laboratory-based study (Level 3 evidence) assessed the safety of HINS light by exposing osteoblast cultures to 405 nm light.
No damage to cells was observed at intensities up to 5 mW/cm² over 2 hours.
Simultaneously, there was a strong bactericidal effect against Staphylococcus aureus and Staphylococcus epidermidis.
4. Range of Inactivated Organisms
Multiple laboratory studies (Level 3 evidence) have shown that HINS light can inactivate a wide range of bacteria, including:
Healthcare-associated pathogens: S. aureus, MRSA, S. epidermidis, C. difficile, Mycobacterium terrae, Mycobacterium smegmatis
Foodborne pathogens: Salmonella enterica, S. enteritidis, Shigella sonnei, Listeria monocytogenes, Campylobacter jejuni, E. coli O157:H7, Bacillus spp., Propionibacterium acnes, Pseudomonas aeruginosa
5. Differential Susceptibility
Studies indicate that Gram-positive bacteria are more susceptible to HINS light inactivation than Gram-negative bacteria.
6. Vegetative Cells vs. Endospores
Although both vegetative cells and endospores can be inactivated, vegetative cells require significantly lower doses compared to endospores for effective inactivation.
7. Surface and Biofilm Penetration
HINS light has been shown to inactivate bacterial biofilms on both glass and acrylic surfaces, including the underside of transparent surfaces, indicating that it retains antimicrobial activity through transmission.
8. Use on Liquids and Exposed Surfaces
HINS light was also effective in inactivating bacteria in liquid suspensions and on exposed surface areas, as demonstrated in lab-based studies.