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.

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, EPIDEMICS, and INFECTIOUS ILLNESSES and AIRSPRAYS, BURNERS and AEROSOLS for details of how to use the oils.