Nasal sebum, also known as nose grease/oil, is grease removed from the surface of the

human nose The human nose is the most protruding part of the face. It bears the nostrils and is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones ...

. The pores of the lateral creases (where the nose joins the face) of the exterior of the nose create and store more oil and grease than pores elsewhere on the human body, forming a readily available source of small quantities of grease or oil.

Sebum chemical composition

Sebum is produced by sebaceous glands from the skin. Sebum has a complex composition that is different from epidermal lipids found anywhere in the human body, for example, squalene and

wax Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low ...

esters are only found in sebum. Triglycerides and

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...

s, taken together, account for the predominant proportion (57.5%), followed by wax esters (26%) and squalene (12%). The least abundant lipid in sebum is cholesterol, which with its esters, accounts for the 4.5% of total lipids.

Other uses of sebum

Nose grease has been reported to be a convenient durable

lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...

. Nose grease can be used to minimize scratches in optical surfaces, for example when cleaning photographic negatives.

Observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. His ...

lore holds that nose grease was used to reduce

stray light Stray light is light in an optical system, which was not intended in the design. The light may be from the intended source, but follow paths other than intended, or it may be from a source other than the intended source. This light will often set a ...

and reflections in transmissive

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

s before the development of vacuum antireflective coatings. The antireflective properties are due in part to the fact that the nose oil fills small cracks and scratches and forms a smooth, polished surface, and in part to the low

index of refraction In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ...

of the oil, which can reduce surface reflection from transmissive optics that have a high index of refraction. The same effect is sometimes used by

numismatic Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related objects. Specialists, known as numismatists, are often characterized as students or collectors of coins, but the discipline also includ ...

hobbyists to alter the apparent grade of slightly worn coins. Nose grease is often recommended as a lubricant for fly fishing rod ferrules. Nose grease has mild antifoaming properties and can be used to break down a high

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...

on freshly poured

beer Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from ce ...

soft drinks A soft drink (see § Terminology for other names) is a drink that usually contains water (often carbonated), a sweetener, and a natural and/or artificial flavoring. The sweetener may be a sugar, high-fructose corn syrup, fruit juice, a s ...

. Wiping nose grease onto one's finger and then touching or stirring the foam causes it to dissipate rapidly. ''The Doctor's Book of Home Remedies'' suggests using nasal sebum as a remedy for

chapped lips Cheilitis is a medical condition characterized by inflammation of the lips. The inflammation may include the perioral skin (the skin around the mouth), the vermilion border, or the labial mucosa. The skin and the vermilion border are more common ...

References

{{reflist Non-petroleum based lubricants Nose