Mosquito Repellent Spray (do not eat)

I was looking for an alternative to DEET for mosquitoes and a friend gave me this recipe for mosquito spray.
In 4 oz. glass spray bottle with fine mist, mix 3 oz distilled water with the following oils:

• 15 drops citronella 
• 10 drops lavender 
• 10 drops eucalyptus 
• 5 drops lemongrass

Make sure you use a glass spray bottle since oils will penetrate plastic, and use high quality oils.