Propionibacterium Acnes, also known as p. acnes, is the type of bacteria that causes inflammatory acne. Blue light has been shown to kill propionibacterium acnes bacteria in as little as 6 seconds of exposure.
The most effective wavelength of blue light against this bacteria is 415 nm. A host of studies have proven blue light therapy as an effective acne treatment, and blue light gained FDA approval for acne treatment around 2000. Learn more.