For respiratory infections –inhale on its own or blended depending on the condition, we like it blended with some Lemon essential oils.
To assist with studying, focusing– vapourise a drop perhaps with some Lemon essential oil or apply a drop to a tissue and inhale
For stress, anxiety, depression and/or nervous tension try vapourising a couple of drops with bergamot or other citrus peel oils of your preference. Lavender could be tried too. Blends can be used in personal inhalers.
Tisserand and Young do not indicate any special hazards when using silver fir needle Essential Oil, however they warn that oxidised oil should be avoided as it may cause skin sensitization. Reading Tisserand and Young's full profile is recommended. [Robert Tisserand and Rodney Young, Essential Oil Safety (Second Edition. United Kingdom: Churchill Livingstone Elsevier, 2014), p.282]