It is based on a synthetic chemical, known as a perfluorocarbon.

In some definitions feed and water must be free of pesticides or other synthetic chemicals.

Our defenses are general ones; they do not discriminate between natural and synthetic chemicals.

Farming without synthetic chemicals is less polluting, according to researchers.

At present, most food preservatives are made from synthetic chemicals.

Compounds can be made from others by scientists and these are called synthetic chemicals.

But above all, a synthetic chemical lacks the life-force found only in nature.

In all, we are probably exposed to at least two hundred different synthetic chemicals every day - and some people will encounter many more.

Why are some people apparently made ill by everyday synthetic chemicals?

It is possible, however, that synthetic chemicals might affect the immune response in some way.