I have seen several suggestions that one should store developer in amber glass containers and not plastic one. I have a box of 500ml amber plastic bottles and another box of 250ml amber plastic bottles for Dectol and Xtol, respectively. I have never had a problem with either since I get all the air out of the bottles when I store them. Am I kidding myself. Since I got these at a drug store, I know these are for medicines that are light sensitive. My guess is that if they are not safe for developer, they must not be safe for our meds either.