Here’s what consumers have asked with answers from L'Oréal Paris staff and previous consumers.
Direct sunlight - It will warm up or heat the chemicals, causing them to separate and rendering the dye useless. Air - Air causes rapid oxidation. If the product contains peroxide, it will interact with the oxygen in the air and cause the dye to go bad. Moisture - Moisture damages packaging if the hair dye comes in a box, and can lead to oxidation as well. Micro-organisms - Bacteria and microorganisms can interact with the chemicals and thrive in the ammonia present in the dye, causing several chemical reactions that will cause the dye to go bad. https://donparkersales.com/hunter-automotive-equipment/