N

nail polish remover

This strong synthetic chemical mix consists of a solution of acetone (or a related chemical) mixed with conditioning ingredients (which may include petrochemicals like propylene glycol). Acetone is a highly flammable, volatile solvent that can dissolve many plastics; it. can be fatal if swallowed. The conditioning ingredients do little to mitigate acetone’s strongly drying and degreasing effects. Also see ketones.

NaPCA

See sodium PCA.

naphthol

See 1-na phthol.

native extracts

This term refers to botanicals extracted by a solvent (or mixture of solvents) and then concentrated under reduced pressure until all the solvent is removed. They’re usually of high potency, and solid, fluid or powdered extracts of varying concentrations are derived from them.

natural colors

Derived from plants (such as indigo) or insects (such as the cochineal beetle), natural colors are appropriate for use in natural cosmetics. See colors.

colors.

NDELA

See nit rosamines.

]VDGA

NDGA (nordihydroguariaretic acid) is an antioxidant used in trace amounts in cosmetics. Whether made synthetically or derived naturally from the creosote bush, it’s toxic and has caused kidney damage.

nephritic

In herbology, a substance that helps kidney problems such as nephritis.

nerol

This aromatic alcohol is found in a number of herbal essential oils, including immortelle, hops, labdanum, lemon petitgrain, lemongrass, orange and rose. Essential oils containing high concentrations of nerol, geraniol, eugenol, betapinene and/or furfurol have antimicrobial properties against Staphylococcus aure us, Escherichia coli, Candida albicans and a Mycobacterium species.

N-hexane

This toxic compound is used in concentrations of 0.01% to 0.1% in cosmetic creams, toothpaste, deodorants and antiperspirants. To be effective at low concentrations, it’s usually combined with parabens, chiorocresol and B-phenoxyethanol. Human studies show allergic reactions to this chemical.

Soluble in alcohol, glycerol, propylene glycol, polyethylene glycols and to some extent in water, it’s supplied as a white crystalline powder. N-hexane is cation ic, incompatible with anionics, various gums, natural soap and sodium alginate, and is unstable at temperatures above 700 C. It’s sold under the trade names of Hibitane, Novalsan, Rotersept, Sterilon, Hibiscub and Arlacide.

nitric acid

This inorganic acid is used as an oxidizer and stabilizer in cosmetics. It’s a corrosive liquid that can irritate skin; inhalation can irritate the lungs and bronchial passages. Oral doses can be fatal.

nitrites

See carcinogenicity in cosmetics.

nitrocellulose

This flammable synthetic substance (similar to gun cotton) is used as an emulsWer and protective film in cosmetics, especially nail polish.

nitro

nitro dyes

See colors.

nitrosamines

This class of compounds. formed from secondary a mines by the addition of nitrous acid, have been found in animal experiments to be very carcinogenic. More than 120 N-nitroso compounds have been examined and about 80% of them have been found to be carcinogenic to some degree.

nonionic

Having a neutral electrical charge. Compare anionic and cationic.

nonoxynol compounds

This large group of ethoxylated alkyl phenols are widely used as surfactants and dispersants. Like all phenols, they’re toxic and should be avoided.

nucleic acids

Either of two groups of complex acids (DNA or RNA) that determine the genetics of living things. These substances are added to cosmetics with the claim that they will strengthen cellular rejuvenation of the skin, but this is just a sales pitch.