Shelf Life and Storage from the time of distillation:
The shelf life of essential oils are very dependent on the conditions they are stored in. Temperature, light and exposure to air can degrade or even destroy a essential oil special properties.
Temperature in excess of 70 degrees can degrade many essential oils over a short time span. It is best to keep the essential oils in a cool place. The temperature range of 60 to 68 degrees Fahrenheit works well for most essential oils.
UV light can also degrade essential oils so it is best to store them in a container that is dark. Cobalt blue glass bottles work well for this purpose.
Exposure to air will also degrade the oil as the oxygen in the air will oxidize the oil over time. Essential oils need to be in air tight container with special caps.

General shelf life from a chemical family perspective:
About 1-3 years – Monoterpene rich oils, Monoterpene/Oxide (cineole) rich oils, Monoterpene/ Aldehyde rich oils, Monoterpene/Monoterpenol rich oils.

About 3-5 years – Monoterpenol rich oils, Monoterpenol/Ester rich oils, Ketone
and Phenol rich oils (Phenols are closer to 3 years).

About 6-8 years, or longer – Sesquiterpene rich oils, Sesquiterpenol rich oils.

Natalchemy ships essential oils in containers that are optimum for essential oil storage. You just need to keep them in a cool place out of direct sunlight. Keep the cap on tightly when not using the oil will also help the oils last longer.
Natalchemy uses the oils we sell in our own products. This ensures that all oils are fresh from the distillers. Natalchemy uses a batch control system and dates the oils to ensure they are always as fresh as possible. All oils have a best if used by date on them to indicate approximate shelf life of the oil.
If the essential oil has are kept out of direct sunlight, closed, and cool, we can make some generalizations on the shelf life of the oils.
Please note these are simply opinions based on experience and an understanding of the chemistry of each of the essential oils.
Note that if an essential oil begins to appear cloudy, thicker, or if it smells more acidic, it has likely begun to oxidize.