Here at OBUS we want you to enjoy the healing power of essential oils. To ensure your use is therapeutic and safe we offer guidelines for blending, and cautions where needed. And all of our products list their specific warnings on their product pages.

Most people using essential oils never have adverse reactions to them, but unfortunately some do. Most adverse reactions are temporary, but some are not. All can be avoided. 

Skin irritation, the most common adverse reaction, is caused by applying essential oils to the skin undiluted or in the wrong dilution, or by applying essential oils to sensitive skin.

What does it look and feel like? 

The skin becomes red, itchy, painful or produces small blisters where you have applied the essential oil. It is temporary, lasting only a few hours, and once you stop using that essential oil the irritation clears.

However, you will most likely have a reaction to that oil or component every time you use it unless you increase dilution.

If you develop an irritation to an essential oil or a blend of essential oils:

  • Stop using the oil immediately.
  • Gently wash the skin with unscented soap to remove any of the oil that is still on the surface.
  • Apply a vegetable oil, like grapeseed, to create a barrier and further dilute.
  • Do NOT apply any essential oils to heal the irritation.
  • Take an over-the-counter antihistamine if the irritation is very itchy.
  • Seek medical advice if recovery is slow.

How to prevent it:

  • Unless you are a professional Aromatherapist, do not apply undiluted essential oils to the skin, and even then, be aware of the risks.
  • Do not use essential oils on skin that is already irritated. Begin treating with just vegetable oils.
  • Use known irritating essential oils with care and at the recommended dilution.
  • Never use known irritating oils in the bath.

Sensitization can be avoided by proper dilution, and paying attention to cautions. 
It happens when you become sensitive to an essential oil, or a component of an essential oil, with overuse or incorrect use. Sensitization may not show with the first or second application because the immune system handles it. However, repeated applications trigger the immune system.

Once you become sensitized to an essential oil or a component you will continue to have a reaction to that essential oil or component every time you come in contact with that oil – even if the next encounter is by diffusion.

Sensitization to an essential oil can last many years to a lifetime.

What does it look and feel like?

The skin can become red, itchy, painful or produce small blisters where you have applied the essential oil. Because this is an immune reaction the rash can sometimes appear on other sites of the body where you have not applied the essential oils.

How to prevent it:

  • Never use known sensitizing essential oils undiluted on the skin.
  • Some sensitizing essential oils are not suitable for diffusion.
  • Use known sensitizing essential oils in the correct dilution and for short periods only.
  • Consider the risk of sensitization before using and consider an alternative essential oil.
  • Never use known sensitizing oils in the bath.

Some essential oils have chemicals that react with UV light, which can cause sunburn and blisters. It is temporary and heals in a few days depending on how strong a reaction you had, and how you treat it.

What to do if you have a phototoxic reaction:

  • Get out of the sunlight.
  • Wash your skin with a mild soap.
  • Apply a sun factor 50 to skin you can not cover (face and hands).
  • Apply a soothing lavender lotion.

How to prevent it:
Use phototoxic essential oils at the recommended dilution. 


Essential oils should never be applied in or close to the eyes. If you accidentally do get essential oils in your eyes flush the eyes with water immediately.

To flush:

  1. Hold your eye under running water for 20 minutes.
  2. Use clean, lukewarm tap water.
  3. Hold the lids of your affected eye open to allow a thorough flush
  4. After a few moments remove contact lenses if they don't come out during the flush -  but make sure to wash your hands thoroughly with soap to remove any essential oils from your hands before touching your eyes. 

Ingestion of essential oils, whether encapsulated or not, should only be carried out under supervision of a professional, and then only for short periods.

Ingestion of excessive amounts and for long periods can lead to strong adverse conditions. 

Accidental ingestion by children:
Keep essential oils out of reach of children as ingestion for young children can be fatal.

If child ingests 

  • Do not induce vomiting.
  • If they are conscious rinse their mouth out with water.
  • Seek medical advice without delay.

Ambient diffusion of essential oils is generally safe for everyone, while intermittent diffusion is best. If diffusion causes a headache, turn off the diffuser and ventilate the room. 

COPD and Asthma
For people suffering from COPD, Asthma or any other respiratory condition that restricts the air flow, it is important to remember that diffusion of essential oils in their space may cause discomfort. 

Diffuse for short periods of times only, and if they begin to clear their throat or cough, then they are having difficulty processing the airborne molecules. Stop diffusion and ventilate the room.