Why are essential oil bottles always brown?

According to chemical knowledge, easily decomposable chemical reagents are stored in brown bottles.

Some essential oils have strong photosensitivity, such as bergamot essential oil, as well as various citrus plant essential oils such as lemon, lime, and bitter orange, which are highly photosensitive. These types of essential oils must be stored in brown cosmetic glass bottles.

Currently, almost all essential oils are stored in dark cosmetic bottles, such as common rose essential oils, lavender essential oils, tea tree essential oils, etc. Although these essential oils are not photosensitive, they are also stored in dark bottles.

The reason is to avoid the evaporation of essential oils caused by the temperature increase caused by sunlight exposure. The essential oil components contain a large amount of aromatic substances, and the volatility of aromatic substances is high.