So we have had this issue on and off for quite a while. We have only experienced it a few times because we have been much more careful since. But we work on a alot of high end upholstery and carpets. We have run into a problem with 100% cotton items turning yellow 10 seconds after they go into the sunlight with peroxide. Peroxide on it is fine, sunlight is fine, the combination is death to any fabric I am working on that does it. It is a highlighter yellow color (not chem burn) using plain peroxide so it is not a PH problem. Have tried rinsing with stabilizers, acidic acid, and ammonia and such just trying to get it to change. First piece we ended up buying and then tried to bleach it and that would not get rid of the highlighter yellow. Does anyone have a solution as to exactly why its happening and what is causing it.... On a side note we had purchased a COBB UV light months back, we have the same reaction while using. I noticed today though that the towels I was using to cover part of the area had actually stopped glowing under the UV light (normally like a bowling alley) So i shut the light off and low and behold where it stopped glowing was not highlighter yellow. So we are not in the middle of having a problem, just trying to figure out why and if there is a way to correct it after, and if anyone has figured this out yet. Thank you all for any input