F.

Abbreviation for Fahrenheit, the temperature scale (used pretty much only in the U.S.) in which water

freezes at 320 and boils at 2120. Compare C.

fats

Fats are a class of chemical compounds that are insoluble in water but are soluble in alcohol, ether, the glycerides of one or more fatty acids, and other solvents. Obtained from rendered animal fat, oil seeds or fruit pulp, they’re used as emollients in cosmetics. Fats can be solid, semisolid or liquid.

fatwy acid esters

These esters of unsaturated fatty acids yield resins that are used in many industries. In cosmetics, they’re often used to compound synthetic fragrances or as flavors. There’s the possibility of allergic reactions to some chemicals used in the esterification process (a condensation reaction in which the molecule of an acid unites with a molecule of alcohol, with the elimination of a molecule of water). The alkyl salt of carboxylic acid is an example of a fatty acid ester.

fatty acids

Saturated aliphatic monocarboxvlic acids is the chemical term for these organic oils that are found in vegetable and animal fats. They can be either saturated (e.g. palmitic, stearic) or unsaturated (e.g. oleic, linoleic, linolenic).

Fatty acids frequently occur in the form of esters and glycerides and are obtained by hydrolysis of fats or by synthesis. Thevre excellent emollients for the skin and an important part of the diet (especially in the form of essentialfatty acids).

fatty alcohols

These alcohols of cetyl, lauryl, oleyl and stearvi fatty acids are thick to semi-thick, syrup-like liquids with high emolliency. They can be natural or synthetic, and are sometimes used in hair and skin conditioners, creams, lotions and conditioning shampoos.

favus

This parasitic fungus disease that attacks the scalp of humans is characterized by yellowish, dry incrustations resembling a honeycomb. Regular use of an herbal hair rinse and conditioner containing the herbs horsetail and coltsfoot can be helpful.

FDA

The Food and Drug Administration, the federal agency responsible for regulating the safety and efficacy of all foods and drugs sold in the US.

FD&C

When this abbreviation precedes the name of a color, it means that the FDA has certified it as safe for use in food, drugs and cosmetics. Compare D&C and Ext. D&C, and see colors and certtfied colors.

febrifuge

In herbology, a substance that reduces or stops a fever.

fermentation

The chemical decomposition of organic compounds into a simpler compound through the action of enzymes or certain bacteria.

ferric chloride

Made by boiling iron in chlorine, ferric chloride is used in medicine and cosmetics as an astringent or styptic. it’s available as a tincture or in a water solution, and it may irritate the skin.

ferricferro cyanide

This dark-blue powder, also known as Prussian blue or iron blue, is exceedingly toxic.

ferrous sulfate

This astringent salt of iron is used in cosmetics as an antiseptic and in medicine to treat anemia. It’s a suspected carcinogen.

fingernails, care of

Fingernails are composed of kera tin (a protein also found in hair). The hard nail plate isn’t living tissue, but the bed it rests on contains blood vessels. The fold of skin at the base of the nail is called the cuticle.

The fingernails have traditionally been decorated in various ways. Long, decorated fingernails are a sign of wealth and leisure, since they’re difficult to maintain in jobs that require manual labor. Because the nail is so tough, nail polishes, nail polish removers and cuticle removers are among the most caustic and damaging of cosmetics. There are practically no natural nail products.

Application of rose hip oil, white camellia oil and evening primrose oil can strengthen nails, and the intake of cysteine, an amino acid, can improve fingernails. Also see amino acids, cysteine, rose hip oil and white came Ilia oil.

5-bromo-5-nitro- 1, 3-dioxane (Bronidox L)

This extremely toxic preservative is so corrosive that it will eat right through metal containers. It’s an active ingredient in propylene glycol and in a compound known as o-Acetal, o-formal. The European Economic Community suggests using it in cosmetics at concentations of 0.1%.

fixatives

Fixatives are materials that retard the evaporation of the more volatile components in perfume formulations. They’re usually of a high molecular weight, and have a high boiling point.

fixed (fatty) oils

These are chemically the same as fats, but they differ physically in that they’re generally liquids at room temperature.

fluoride

Flourides are compounds of the element fluorine. Although toxic, they’re used in toothpastes as an antienzyme ingredient to retard tooth decay, and are added to the water supply in some states and localities.

follicle

A small cavity or depression in the skin that contains the hair root.

formaldehyde

A suspected carcinogen, this colorless, pungent, irritating substance is found in many preservatives, such as the hydantoins; it’s also used as a disinfectant. It’s acutely toxic when inhaled or swallowed, and 4400 of all people whose skin is exposed to it get a toxic reaction.

At one point, the FDA banned formaldehyde from cosmetics, but it’s now used in shampoos at concentrations of 0.1% to O.20o. If its concentration is greater than 0.0500, the European Economic Community requires that formaldehyde be identified on a product’s label, but this isn’t required in the U.S.

Methanol is sometimes added to formaldehyde at a 15% concentration to prevent polymerization.

Formalin

A trade name for formaldehyde.

formic acid

This toxic organic acid is a colorless liquid with a pungent odor. Avoid all contact of formic acid with the skin. A 10 g dose is dangerous, and a 50—60 g dose is lethal. The European Economic Community limits its concentration in cosmetics to 0.5%.

Formic acid has been used as a food preservative since 1865 in the form of sodium, potassium or calciurn formate, but this isn’t allowed in the United States. Formic acid has a pH of 3.5. It was first observed by Fischer in 1670, in ants.

Formol

A trade name for formaldehyde.

forsythia

In China, this fruit is known as lien-chiao. It’s used as an anti-inflammatory and to treat skin problems. See chin g-s hang.

4-isopropyl-3-methylphenol

Since this is a phenolic substance, it should be regarded as toxic. Manufactured in Osaka, Japan, it goes under the trade name of Biosol.

freckle

A yellow or brown spot on the skin, usually caused by sunlight.

fruit acids

As their name suggests, these acids are found in various fruits and herbs. Also known as alpha hydroxy acids, red fruit acids and amidroxy fruit acids, they’re used in masks and moisturizers for their ability to exfoliate and moisturize the skin.

The principal fruit acids are citric, glycolic, malic and lactic. Usually associated with milk, lactic acid is also found in some plants—milk thistle, shea butter and coconuts, for example. The other fruit acids are mainly found in citrus fruits, apples, bilberry. black currant and sugar cane.

Fruit acids are used in concentrations as low as 0.25% and as high as 8%. The higher concentrations increase the "heat" of the product and the peeling action, but can also cause skin irritation in some people.

fuller’s earth

This kind of clay is used for its moisturizing ability. It can often be found as an ingredient in facial mud pack treatments.

fungicide

A substance that kills fungus.