1. Shelf life after opening: The shelf life of toner after opening is usually shorter than before, as it is easily affected by factors such as air and bacteria.
2. Consideration after one and a half years: It is generally recommended to use toner as soon as possible after opening, usually within 3 to 6 months to ensure its effectiveness and safety. After one and a half years of opening, the toner is likely to have deteriorated, its chemical composition and active substances may have changed, and it is no longer suitable for skin care.
3. Safety advice: From the perspective of safety and effectiveness, it is not recommended to use toner that has been opened for one and a half years. It is recommended to regularly check and discard expired or long unused cosmetics to avoid potential adverse effects on the skin.