Allergy
An abnormal sensitivity (hypersensitivity) to a Substance or food
which wouJd not provoke a .reaction in, or prow! completely harml-ess
to, most people. (See the section on skin disorders, page 306.)
The substance causing the a:Uergic reaction is known as an allergen
or sensitiser. Th.e most common sen..sitisers in the cosmetic industry
are perfumes and colourants, although the widening range of chemjw
cal compounds used in making various products can cause skin
irritations ·which affect only certain individuals. Even hypoalle:rgenic
(supposedly non-allergy causing) products will cause a reaction in some people.
The European Community (EC) is consulntly reviewing the ingredients
used bv the cosmetic, medical and food trades in order to.
eliminate potential sensiti ers and ham1ful ingredients. Proven harmful
ingredients a.re then banned from use throughout the EC. One
example of this was the ban placed on certain nail varnish colowllnts
proved to be potent sensitisers. Manufacturers we.re forced to find
alternatives and for quite a while popular colours were changing
subtly with every b~tch of product made! Because of this care being
taken, our cosmetics are becomillg safer .and less aUergenic as time
goes on.
Detergent
A substance which is ab1e to mix fith both oil and and ovater. Because
of this ability, some detetgents can act as emulsifiers or emulsifying
agents. For example, in their usual states, oU and water will not ll1ix
but will fotm two separate layers in a contain.er, one floating above
the other. By bridg1ng the oil and water states, the detergent breaks
the oil into tiny droplets. These become suspended evenly in the
water, fonnittg an emulsion. Because they emulsify thoily films
which trap dirt in the fibres of a fabric1 allo"ring the dirt to become
wet and float away, detetgents are used as deaning agents.
Emollient
An emtllient is a substance: which softens living tissue. Examples are
spermaceti substitute, beeswax, ptittoleum jelly, lan.olin, minetal oil,
