Aromatherapy: Understanding Antiseptic Oils

Most essential oils have natural antiseptic properties because the plants from which they are extracted produce them to protect themselves from invading micro-organisms. Tea tree is one of the best known and most versatile essential oils with powerful antiviral, antibacterial and antifungal properties, yet it's gentle enough to treat children.

Treating infections

Antibacterial oils can be used for a number of treatments. A cold compress with a few drops of thyme or lavender, for example, can be applied to cuts and grazes. Urinary infections respond well to aromatic bathing while chest rubs, dry and steam inhalations can be used to treat viral colds and symptoms of flu.

Skin infections require gentler antiseptic action. Lavender and tea tree are ideal as these are the only oils that should be applied neat to spots.

Sources of Antiseptic Essential Oils

Antiseptic essential oils can be extracted from citrus fruits and Mediterranean herbs. Natural antiseptics can also be found in the resin, leaves and twigs of many trees. Members of the labiate family, including most of our familiar garden herbs, are also a source of antiseptic oils. Examples of these include thyme and sage, which are particularly pungent, and rosemary, which has a sweet aroma.

Aromatic Antiseptics

Bracing, fresh and camphorous, the scent of tree oils from eucalyptus, pine and tea tree share similar properties though they come from different parts of the world. The stimulating, pungent odour of these oils indicates their powerful antiseptic action. In contrast, the antiseptic oils derived from citrus fruits all share fresh and zesty frangrances, while the deep, woody perfumes of resinous frankincense and myrrh have long-lasting aromas that also disinfect.

Key to Antiseptic Oils

The many active constituents in antiseptic essential oils work to provide them with powerful germicidal properties and also lend them distinctive aromas.


High concentrations of phenols thymol and carvacol give thyme its germicidal action.

Sweet thyme is low in phenols.

Thymol and carvacol are also irritants, so use thyme oil sparingly.

Thyme essential oil


Rich in monoterpenes such as pinene and mycene, which give pine its deodorising and disinfectant properties. The needles and cones of pine give a clear refreshing oil.

Tea tree

Gentle and mild, tea tree is a powerful antiseptic oil, due to its active constituents of monoterpenes, cymene and terpineol. Tea tree is an effective antiseptic oil that can be applied neat.


There are more than 500 species of eucalyptus that yield essential oils useful for disinfection. All have bacteriostatic activity and anti-infection properties. Eucalyptus's potency differs between species.

lemon aromatherapy


Lemon's antiseptic action is due to its principal component, limonene. The oil is a popular choice for household cleaners. The aldehydes in lemon give it a light, citrus scent.


Rich and resinous, benzoin is especially rich in esters such as benzyl benzoate, which are antiviral and provide a sweet, floral scent. Benzoin is a gentle treatment for urinary and skin infections.


Cajeput's antiseptic properties are due to its active constitents of terpineol and terpenes. Cajeput's scent is sweet and penetrating.

Antiseptic Blends

First aid treatment

Treat minor cuts and abrasions with a cooling antiseptic compress:

  • 2 drops lavender
  • 6 drops tea tree
  • 2 drops thyme

Urinary infections

Add gentle antiseptic oils to a warm bath for healing relief from cystitis:

  • 2 drops benzoin
  • 2 drops juniper
  • 5 drops rosemary

Cold and flu

Massage a blend of antiviral essential oils onto the throat, neck and chest to combat respiratory infections:

  • 3 drops eucalyptus
  • 2 drops lavender
  • 3 drops rosemary
  • 30ml carrier oil

Natural fumigation

Prevent the spread of coughs and colds at home or work by fumigating rooms with a fine mist spray. Dilute the oils in 50ml of water:

  • 5 drops eucalyptus
  • 5 drops lemon

Constituents of Antiseptic Oils

Most constituents of essential oils have some degree of antiseptic activity, but those rich in the following compounds are considered to be particularly germicidal.


Abundant in most distilled oils, these are bacterial and antiviral.


These have valuable anti-infection properties.


Oil rich in phenols need to be used sparingly as they can cause skin irritations.