Not any time soon.
And if we do run out of pigments, it may well be that because
humankind, itself, has ceased to be.
But first, a story or two...
When I was a lad, I had a Gilbert Chemistry Set that included in its
contents a small bottle of intensely-colored red powder labelled
Cochineal.
The book that came with the set explained that Cochineal was a
traditional pigment made from the crushed-up remains of an insect,
which gave this particular bottle an enormous "Ewwww" factor as my
friends and I conducted our many experiments.
You can see a bit more about cohineal -- both the bug and the pigment -- here:
http://en.wikipedia.org/wiki/Cochineal
I bring this story up, because if something were to happen to the
cochineal insect -- if it were to go extinct -- then the supply of
natural cochineal pigment would disappear along with it. We would,
indeed, run out of cochineal!
Years later, as a budding marine biiologist, I conducted a number of
oceanographic experiments with a substance known as Rhodamine B,
another intense red material (this one a dye -- that is, a liquid --
rather than a powdered pigment) which was used back then as a tracer
dye in the ocean. Even small amounts of Rhodamine B could stain a
large area of seawater, which could then be tracked for a long period
of time through the persistence of the red color.
Rhodamine B is a synthetic chemical. Unlike cochineal, it is not
extracted directly from a bug or a plant, but is made in a
manufacturing plant fromm very abundant raw materials. Since there
are very many synthetic pathways for making most chemicals, there is
no reason to suppose that the materials needed to make additional
amounts of Rhodamine B would run out any time in the foreseeable
future.
The ability to synthesize many pigments requires us to revisit the
cochineal story. It is indeed possible to run out of
naturally-occuring cochineal. But if we could find a means of
synthesizing the pigment, then the supply of artificial cochineal
would then be pretty much inexhaustible.
Pretend that a blight eliminated the vanilla plant from the face of
the earth. Would that, then, mean the end of Vanilla Coke? No,
because the clever chemists in the food industry have figured out how
to make synthetic vanilla.
The same could be (and has been) done for many pigments as well, so
there is no reason to suppose that supplies of these synthetic
pigments will run out.
Not all pigments are synthetised. Some are mined, and like any mined
product, may run out one day. But I am not aware of any impending
shortages of pigment materials.
For instance, have a look at the list of common commercial paint
pigments from this article:
http://en.wikipedia.org/wiki/Pigment
PAINTING PIGMENTS
Alizarin (Alizarin Crimson)
Bone black (also known as bone char)
Cadmium pigments (Cadmium Green, Cadmium Red, Cadmium Yellow, Cadmium Orange)
Caput Mortuum
Carbon black
Cerulean blue
Chromium pigments (Chrome Green, Chrome Yellow)
Cobalt pigments (Cobalt Blue)
Crimson
Fugitive pigments
Gamboge
Indian Yellow
Indigo
Ivory black
Vine black
Lamp black
Mars black
Lead pigments (Lead white, Naples Yellow, Cremnitz White, Foundation
White, Red Lead)
Paris Green
Phthalocyanine (Phthalo Green, Phthalo Blue)
Prussian blue
Quinacridone (Quinacridone Magenta)
Oxide Red
Red ochre
Sanguine
Sienna (Raw Sienna, Burnt Sienna)
Titanium dioxide (Titanium White)
Ultramarine (Ultramarine Green Shade, French Ultramarine)
Umber (Raw Umber, Burnt Umber)
Van Dyke brown
Venetian Red
Verdigris
Vermillion
Viridian
Yellow ochre
Zinc white
You can click on any of the pigements listed at this site to see more
information about it.
You'll see some, like carbon black, that will be around as long as
there is wood, bone or other carbon-containing materials to make into
charcoal.
Others, like titanium dioxide (the intense white of both paint and
some sun-block creams) exists in abundant supplies in the earth, and
can even be mined from many beach sands. Again, there's no reason to
suspect a shortage of these raw materials in the foreseeable future.
Lastly, I want to make mention of the most important pigment to
humans, and that is choloryphyll -- the green stuff that allows plants
and plankton to photosynthesize, and oxygenate the atmosphere:
http://en.wikipedia.org/wiki/Chlorophyll
If we run out of chlorophyll -- which is the same as saying we run out
of green plants -- then we're history!
Hopefully, that won't be happening any time soon.
I trust this information fully answers your question.
However, please don't rate this answer if you find you'd like
additional information. Just post a Request for Clarification to let
me know how I can assist you further, and I'm at your service.
Cheers,
pafalafa-ga
search strategy -- Used my own knowledge about pigments, along with
Google searches on:
rhodamine
chlorophyll
cochineal
pigments |
Clarification of Answer by
pafalafa-ga
on
23 Oct 2005 13:11 PDT
Good question, but there isn't a simple answer to it.
Since each pigment is comprised of different elements, chemists need
to rely on different starting materials for synthesis.
Titanium dioxide, for instance, can be produced synthetically, but
would not be synthesized from oil. Ditto for Cerulean blue, the lead
and chrome pigments, and others.
Rhodamine B is composed of the elements carbon, hydrogen, nitrogen,
oxygen and chlorine. Oil is a good starting material for some of
these elements, like carbon and hydrogen. The chlorine comes from
elsewhere, such as from hydorcholoric acid.
So, I suppose an answer to your question is that, yes, a fair number
of carbon-containing pigments can be said, indeed, to be made from oil
as a starting raw material.
However, industrial chemists are not confined to just using oil as a
starting material -- they do it because oil is abundant, relatively
cheap, and they are familiar with processing it.
But other materials -- such as crop waste (corn husks and stalks, for
instance) can also be used as rich sources of carbon, nitrogen and
other necessary elements.
The world will never run out of these fundamental materials --
elements like carbon and nitrogen are not destroyed, but constantly
cycle through the earth in different forms, as minerals, plant matter,
gasses and so on.
As long as we have access to these material in some form, whether oil
or otherwise, it should be possible to create synthetic pathways to
produce pigments or other synthetic chemicals.
Does that answer your question?
pafalafa-ga
|
