This essential oils dilution chart is to be used as a reference as you are not supposed to use essential oils in their neat form. It is essential to dilute your essential oils before application.
The individual needs of a person and the oil being used should also be considered.
Also, just because 1% dilution (1 drop of essential oil per teaspoon of carrier oil) is considered appropriate for a situation does not mean that all essential oils can be used at that concentration. For example, cinnamon bark essential oil can be irritating if used over a 0.5% dilution (1 drop in 2 teaspoons of carrier oil). If you don’t have a copy of Essential Oil Safety, you can find the maximum recommended dilution for many popular essential oils here.