'Chemicals' per se, are entirely natural

In marketing and advertising, 'chemicals' equate to 'harmful' and 'dangerous'. Companies like to parade the lack of 'chemicals' in their products. Can things be 100% chemical free? The public seems to think so.

But the Royal Society of Chemistry is offering a £1 million prize to the first member of the public who can provide a sample of any material whatsoever that is 100% chemical free.

The truth, as any right-minded person will say, is that everything we eat, drink, drive, play with and live in is made of chemicals - both natural and synthetic chemicals are essential for life as we know it.
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"Should anyone [be able to claim the prize], we will see thousands of years' worth of knowledge evaporate before our eyes. We would have to tear up the textbooks, burn the degree certificates and retrain the teachers."
[...]
The Advertising Standards Authority (ASA) recently defended an advert which perpetuated the myth that natural compounds are free of chemicals. [...] The manufacturers of a popular "organic" fertiliser recently [claimed] in promotional materials the product contained no chemicals whatsoever.

Of course there are harmful chemicals, but the reason they're harmful isn't because they're chemicals. When most people use the term 'chemicals' they're really referring to something else - but what exactly that category is isn't something I'll try to get into here.