Disinfectants are antimicrobial agents that are applied to the surface of non-living objects to destroy microorganisms that are living on the objects. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical and/or chemical process that kills all types of life

All essential oils will either kill bacteria or inhibit their growth to a certain extent, some of them acting on one or two organisms only, and others on a very wide spectrum. A small number of oils will also kill or inhibit viruses. Some of these are very much more powerful than chemical disinfectants, such as phenol {which is used as a standard of comparison in laboratory tests). Among the most useful are Bergamot, Clove, Eucalyptus, Juniper, Lavender, Tea Tree and Thyme.

A recent study by the British Medical Council Complementary and Alternative Medicine studied 21 essential oils, of which 19 oils showed antibacterial properties.

The best of these 19 oils were:

• cinnamon
• clove
• geranium
• lemon
• lime
• orange
• rosemary

Any of these can be used very effectively to disinfect rooms, especially during or following infectious illness. A fairly strong solution with water can be used for swabbing down all washable surfaces, but the best method is to diffuse the oil in the air. This can be done by means of air sprays, an essential oil burner, putting some oil on a lightbulb or radiator or, most effectively of all, with aerosol generating equipment.

See also BACTERIOSTATICS, AIRSPRAYS and BURNERS for details of how to use the oils.