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Urine Fluorescence

Urine fluoresces or glows when exposed to black or ultraviolet light.

Urine fluoresces or glows when exposed to black or ultraviolet light.

Anne Helmenstine
Yes, that is a toilet bowl. While most cleaners fluoresce or glow under black light, I think it's a pretty safe bet this glow comes from urine or other body waste rather than overzealous cleaning. If you want to check the cleanliness of your own toilet, shine a black light around it. Most cleaners would glow blue. Urine glows greenish-yellow.

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