(1) It appears that no machine manufacturer recommends that you add anything to the humidifier water and some suggest that essential oils placed on the filters can interfere with the sensors. Personally, I would think that tobacco smoke in the air would cause the same problem and I have not seen anything about smoking near a CPAP except that it may smell bad to a non-smoker or gunk up the machine after a period of time.
(2) Like all scents, the effect wears off rapidly as your nose adapts to the scent. This is part of your ancestral survival mechanism that uses scent to alert you to changing conditions. Pretty much why people can adapt to the smell of garbage dumps and slaughterhouses. most
(3) While some aromatherapy scents may have exotic or proprietary names, come in small bottles, and may be relatively expensive, you can purchase essential oils at a substantial discount in most health foods stores or online.
(4) The best use for essential scents may be when you are adapting to a new mask and need some "diversion" from the discomfort.
(5) While a number of essential oils may have therapeutic claims, most are anecdotal and can be classified as a "placebo." If you think about it, placebos are the world's greatest drugs. They are cheap, do no harm, and trick your mind and body into producing a beneficial result.
(6) For those who use Oxygen, any oil-based substance may represent a fire hazard and should not be used.
(7) Here is the FDA statement on aromatherapy and essential oils: https://www.fda.gov/cosmetics/productsin...127054.htm
(8) Like all chemicals, there may be specific usage limitations and warnings -- especially if you are pregnant or have a particular heart or lung disease.
(9) Here are some of the common scents
BERGAMOT
CEDARWOOD
CINNAMON
CITRONELLA
CLOVE
EUCALYPTUS
FRANKINCENSE
GERANIUM
GRAPEFRUIT
JASMINE
LAVENDER
LEMON
LEMON GRASS
LIME
PATCHOULI
PEPPERMINT
ROSE
ROSEMARY
SAGE
SANDALWOOD
SPEARMINT
SWEET ORANGE
TANGERINE
TEA TREE
VANILLA
WINTERGREEN