Let's start with a little game to get us thinking
about titanium dioxide. From the list of uses below, put them in the correct
category. If you think titanium dioxide will be found in the product say yes,
and if not put it in the no category.
paints, gasoline, light bulbs, plastics, toothpaste, coloring of foods, sunscreen, diamonds, clothing, ceramics, white out (2)
YES NO
paint gasoline
plastics lightbulbs
toothpaste diamonds
foods
sunscreen
clothing
white out
ceramics
Answer: Use your cursor to highlight the text
How'd you do? Those aren't the only places you will
find titanium dioxide. It can also be found in rubber boots, tires, and
mascara (2). You may be wondering how this random chemical you have never heard of
before ended up in all these things! Well, titanium dioxide is highly
reflective and is easily dispersed (4). These two qualities sound like the perfect
combination for white paint. You want to be able to spread it easily and we
know sun rays reflect off of white. Titanium dioxide is also insoluble,
non-flammable, thermally stable, AND the best part is, it's cheap! (3, 4)
If it's so wonderful then why does everyone have
their knickers in a knot about it? It is believed that its production as
nanoparticles (very, very, very, very small particles), are bad for our health.
But the good news is, we aren't being exposed to enough of it for it to be a
problem (1). Only in very high concentrations does it have the potential to
make us sick (1).
Now I bet you are wondering how it is made (as all
good scientists do). If you were to head deep down into a mine, you would be
able to find the dirty version of the stuff (4). We need it to be "clean"
so we can use it. We can do that in two ways.
1.
Sulfate process - mixing our titanium dioxide sludge with sulfuric acid (4)
2.
Chloride process - mixing the sludge with chlorine gas and petroleum coke
(which looks
similar to coal) (4)
Since we haven't had any problems with using
titanium dioxide so far, we haven't had to think of any backups in case we run
out. But if we did, we could use rice starch (3) to whiten foods or diatomaceous
earth to whiten paint (5).
So next time you are out and about, try and see how
many things you can find that contain titanium dioxide. I bet you will be
surprised!
References
1. Australian Government Department of Health. (2015). Nano titanium dioxide
technical information sheet. Retrieved December 3, 2015 from
http://www.nicnas.gov.au/communications/ issues/nanomaterials-nanotechnology/nicnas-technical-activities-in-nanomaterials/nano-titanium-dioxide-human-health-hazard-review/nano-titanium-dioxide-technical-information-sheet
2. Hext,
P. M., Tomenson, J. A., &
Thompson, P. (2005). Titanium dioxide: Inhalation toxicology and epidemiology. Annals
of Occupational Hygiene, 49(6), 461-472. Doi:10.1093/annhyg/
mei012
3. Industry Sourcing. (2014). Rice starch as an alternative
to titanium dioxide. Retrieved December 3, 2015 from
http://www.industrysourcing.com/article/rice-starch-alternative-titanium-dioxide
4. Lakshmanan, V. I., Bhowmick,
A., & Halim, M. A. (2014).
Titanium dioxide: Production, properties, and applications. Chemical
Physics Research Journal, 7(1),
37-91.
5. Specifier. (2011). Alternatives to titanium dioxide for paint
industry. Retrieved December 3, 2015 from
http://www.specifile.co.za/specifier/coatings-insulation-and-waterproofing/799-alternatives-to-titanium-dioxide-for-paint-industry
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