276 EFFECTS OF CHEMICALS
The Delaney Amendment, dealing with food additives,
has been in place since 1958. A substance which produced
cancer in laboratory animals could not be used as a food
additive. It was overhauled significantly in 1996. More foods
are now covered. However, states cannot set standards which
are more strict than the federal rules. The standard for pes-
ticides in raw and processed food is based on the amount
which may be expected to produce cancer in one person in
a million.
It is estimated that there are as many as 1400 natural and
synthetic flavors available today. Increased use of flavoring
has paralleled the introduction of new food processing and
distribution techniques.
Flavor enhancers are closely related to flavors. The best
known of these is monosodium glutamate (MSG). There is
evidence linking excessive intake of MSG to Kwok’s dis-
ease, sometimes known as “Chinese restaurant syndrome.”
Symptoms include a tightening of the neck and face mus-
cles, at times accompanied by nausea, headache, and gid-
diness. Some countries have placed limits on the amount of
MSG in foods and require that the presence of this substance
be prominently noted.
Color additives are utilized primarily for the purpose of
giving an appetizing appearance to food. Synthetic dyestuffs
are used much more often than natural materials. It can be
expected that the synthetic dyes will be produced in a high
state of purity. In general, small amounts of dye will suffice
to give the desired food color. A material that gives a color
that is durable is needed by the food processor. Regulations
governing the colors that may be added to foods vary mark-
edly from country to country and this causes some difficul-
ties for food processors engaged in international operations.
Some commonly used preservatives are benzoic acid,
sodium benzoate, sorbic acid, monosodium phosphate,
sodium propionate, and sulfur dioxide. Of special interest is
the use of sulfur dioxide for inhibition of mold and discol-
oration in wine. Sulfur dioxide is, of course, a prominent air
pollutant. There is anxiety that the acceptable daily intake
of sulfur dioxide will be exceeded in countries where wine
intake is heavy. Experimental evidence indicates that sulfur
dioxide inhibits the growth rate, probably due to destruction
of Vitamin B 1 by sulfite.
Antioxidants, added to prevent rancidity in fatty foods,
can be put in the classification of preservatives. A second
use for antioxidants is developing with the growing prac-
tice of display of food in transparent containers and wrap-
ping. Attendant exposure to light causes discoloration, not
necessarily detrimental to nutritional value in itself, but
detracting from attractiveness. The most commonly used anti-
oxidants are butylated hydroxyanisole, butylated hydroxy-
toluene, propyl, octyl and dodecyl gallates, and tocopherols.
Antioxidant effect of a substance can often be increased by
addition of a second material, producing a synergistic reac-
tion and allowing more effective product control.
Texture agents include emulsifiers, stabilizers, and thick-
eners. These are the largest single class in terms of total quan-
tity consumed in food. Use of these agents has contributed
greatly to the development of the new convenience foods.The miscellaneous group includes acids, alkalies, buf-
fers, neutralizing agents, anti-glazers, release agents, anti-
caking materials, clarifying agents, and foaming agents. All
of these substances are primarily manufacturing and pro-
cessing aids. Indeed, without many of these materials the
range of modern foods would be much more limited.
Testing of food additives as with most other chemicals,
is not usually done with human subjects. Exposure studies of
both limited duration and long term are made on mice, rats,
dogs, and other laboratory animals. When deviation from
normal response is noted, the largest dosage that does not
produce the change is used as the base for acceptable intake
for humans. Normally, this dosage is reduced by a factor of
about 100 in most countries. The allowable, or accept-
able, dosage is expressed as milligrams of the substance per
kilogram of receptor body weight. It must be emphasized
that extrapolation from animals to humans is always a dif-
ficult undertaking.
International guidelines have been issued by the World
Health Organization and the Joint Expert Committee on
Food Additives of the Food and Agriculture Organization.
The Codex Alimentarius Commission of the Food and
Agriculture Organization has published six principles con-
cerning the use of food additives.1) The use of an additive is justified only when it has
the purpose of maintaining a food’s nutritional
quality, enhancing keeping quality or stability,
making the food attractive, providing aid in pro-
cessing, packing, transporting or storing food or
providing essential components for food in special
diets. An additive is not justified if the proposed
level of use constitutes a hazard to the consum-
er’s health, if the additive causes a substantial
reduction in the nutritive value of the food, if it
disguises faulty quality or the use of processing
and handling techniques which are not allowed, it
deceives the customer or if the desired effect can
be achieved by other manufacturing processes that
are economically and technologically satisfactory.
2) The amount of additive should not exceed the
level reasonably required to attain the desired
effect under good manufacturing conditions.
3) Additives should conform to an approved standard
of purity.
4) All additives in use, or proposed, should be sub-
jected to adequate toxicological evaluation and
permitted additives should be kept under observa-
tion for deleterious effects.
5) Approval of additives should be limited to spe-
cific foods or specific purposes and under specific
conditions.
6) Use of additives in foods consumed mainly by
special groups within the community should be
determined by the food intake of that group.Toxicity is the general term applied to adverse biologi-
cal effects in man resulting from pollutants. Effects mayC005_004_r03.indd 276C005_004_r03.indd 276 11/18/2005 10:21:38 AM11/18/2005 10:21:38 AM