Photochromic indicator and a method of documenting decontamination of an object using a photochromic indicator
Provided is a method and an apparatus for indicating minimum exposure of a surface to UVC light emitted by a source during a decontamination process to achieve a desired level of pathogen reduction. The apparatus includes a photochromic material to be applied to, or applied adjacent to the surface. The photochromic material is to exhibit a visible response to receiving the minimum exposure to the UVC light, and exhibit the visible response to a lesser extent after the photochromic material ceases to be exposed to the UVC light emitted by the source. A protective layer of material that is substantially transparent to the UVC light emitted by the source is positioned over the photochromic material to be disposed between the source and the photochromic material during the decontamination process.
1. An apparatus for indicating exposure of a surface to a minimum predetermined dose of UVC light emitted by a source during a decontamination process, the apparatus comprising:
a photochromic indicator comprising a plurality of regions of photochromic material, wherein the photochromic material exhibits a visible response to receiving the predetermined dose of the UVC light and, after the photochromic material ceases to be exposed to the UVC light emitted by the source, an appearance of the photochromic material returns to an original appearance that was visible before exposure of the photochromic material to the UVC light, wherein each region of the photochromic material exhibits the same visible response when exposed to UVC light, and wherein each region of the photochromic material changes opacity upon exposure to a suitable amount of UVC light to ensure a desired level of pathogen reduction has been achieved, and;
a protective layer of material that is substantially transparent to the UVC light emitted by the source positioned over the photochromic material during the decontamination process, wherein the protective layer is disposed between the source and the photochromic material during the decontamination process.
2. The apparatus of claim 1 , wherein each region of the photochromic material changes color upon exposure to a suitable amount of UVC light to ensure a desired level of pathogen reduction has been achieved.
3. The apparatus of claim 1 , wherein the protective layer comprises a UVC-transmissive material chosen from polypropylene, low-density polyethylene, and fluorinated ethylene propylene.
4. The apparatus of claim 1 , wherein the protective layer comprises a UVC-transmissive material that allows transmission of at least 60% of the intensity of the UVC light emitted by the source.
5. The apparatus of claim 1 , wherein the protective layer has a cross section thickness less than 0.01 inches.
6. The apparatus of claim 1 , wherein each region of photochromic material has the same cross section thickness.
7. The apparatus of claim 1 , wherein each region of photochromic material has a different cross section thickness.
8. The apparatus of claim 1 , wherein each region of photochromic material is made from the same photochromic material.
9. The apparatus of claim 1 , wherein each region of photochromic material is made from a different photochromic material.
10. An apparatus for applying a material that exhibits a visible response to being exposed to at least a predetermined dose of UVC light emitted by a source during a decontamination process being performed on a surface, the apparatus comprising:
a housing defining a reservoir;
a photochromic material disposed within the reservoir to be applied to, or applied adjacent to the surface, wherein the photochromic material exhibits a visible response to receiving the predetermined dose of the UVC light and, after the photochromic material ceases to be exposed to the UVC light emitted by the source, an appearance of the photochromic material returns to an original appearance that was visible before exposure of the photochromic material to the UVC light, and wherein the visible response of the photochromic material is configured to remain visibly perceptible for at least two minutes after the photochromic material ceases to be exposed to the UVC light emitted by the source;
a second material that exhibits a visible response when exposed to a stimulant other than UVC light; and
an applicator that is in fluid communication with the photochromic material in the reservoir and the second material to be supplied with the photochromic material and the second material at a time when the photochromic material and the second material are to be applied to the surface.
11. The apparatus of claim 10 , wherein the stimulant is long-wave ultraviolet light.
12. The apparatus of claim 10 , wherein the applicator comprises a roller rollably supported by the housing to be exposed to the photochromic material that rolls over the surface during application of the photochromic material onto the surface.
13. The apparatus of claim 10 , wherein the photochromic material disposed in the reservoir is substantially transparent when applied to the surface by the applicator before being exposed to UVC light as part of the decontamination process.
14. The apparatus of claim 10 , wherein the visible response remains visibly perceptible for at least four minutes after the photochromic material ceases to be exposed to the UVC light emitted by the source.
15. The apparatus of claim 10 , wherein the visible response remains visibly perceptible for at least ten minutes after the photochromic material ceases to be exposed to the UVC light emitted by the source.
16. An apparatus for indicating exposure of a surface to a minimum predetermined dose of UVC light emitted by a source during a decontamination process, the apparatus comprising:
a photochromic indicator comprising a plurality of regions of photochromic material, wherein the photochromic material exhibits a visible response to receiving the predetermined dose of the UVC light and, after the photochromic material ceases to be exposed to the UVC light emitted by the source, an appearance of the photochromic material returns to an original appearance that was visible before exposure of the photochromic material to the UVC light, and wherein each region of the photochromic material exhibits a different visible response when exposed to UVC light; and
a protective layer of material that is substantially transparent to the UVC light emitted by the source positioned over the photochromic material during the decontamination process, wherein the protective layer is disposed between the source and the photochromic material during the decontamination process.
17. The apparatus of claim 16 , wherein each region of the photochromic material changes color upon exposure to a suitable amount of UVC light to ensure a desired level of pathogen reduction has been achieved.
18. The apparatus of claim 16 , wherein each region of the photochromic material changes opacity upon exposure to a suitable amount of UVC light to ensure a desired level of pathogen reduction has been achieved.
19. The apparatus of claim 16 , wherein the protective layer comprises a UVC-transmissive material chosen from polypropylene, low-density polyethylene, and fluorinated ethylene propylene.
20. The apparatus of claim 16 , wherein the protective layer comprises a UVC-transmissive material that allows transmission of at least 60% of the intensity of the UVC light emitted by the source.