David Suzuki, Canada’s high priest of all things natural is at it again, raising money that is. The David Suzuki Foundation (DSF) is mailing out requests for donations with statements like “We must stem the flow of toxic chemicals into our bodies...” and a “Sustainable Shoppers Guide” that cautions you about “a dirty dozen ingredients to avoid in your cosmetics”.
The Myth
It is obvious, neither Suzuki nor his disciples at the foundation know much about chemistry. Let’s look at the first of the bad dozen. The “guide” says:
Coal tar dyes: Look for P-PHENYLENEDIAMINE in hair dyes, and colours identified as “C.I.” followed by five-digits in other products. Potential to cause cancer and can be contaminated with heavy metals toxic to the brain.
Some Facts
The Merriam-Webster Dictionary broadly defines “coal tar dye” as “any synthetic organic dye”. In historic times, organic (non-mineral) dyes were derived from plants (e.g. madder), snails (e.g. purple dye murex) and other organisms (e.g. cochineal insect). Few of these natural organic dyes were easily accessible, most were difficult and expensive to make, and were available only to the elite.
Over the last 150 years or so, the science of chemistry has been able to determine the structure of these natural dyes and has found ways to mass produce the natural dyes from inexpensive starting materials, such as “coal tar”. In addition, many synthetic dyes were developed, which provide us now with dyes in just about any colour and hue desired.
For example, indigo (CI 73000), the dye used in dying most “blue jeans” is made from “coal tar” products and the like for well over a century. Nature just could not deliver the amounts used today without turning large agricultural areas over to “indigo farming.” The synthetic product is exactly the same as that obtained from the family of 700-plus flowering plants of the Indigofera spp. (Fabaceae). Another natural dye, Tyrian Purple (CI 75800) has been known since ancient times when it was produced from marine murex snails. It is a close chemical relative of indigo and also available as a synthetic product.
P-Phenylenediamine compounds
P-PHENYLENEDIAMINE is a chemical building block of many synthetic dyes and other useful products. While the compound itself has been known to be carcinogenic for a long time, that does not mean that other compounds made from it, or with a similar structure, need to be carcinogenic. For example, N-phenyl-p-phenylenediamine is a non-carcinogen. The same holds true for most of the dyes made from p-phenylenediamine. Looking at the bright colours of the guide, I suspect they are just those phenylenediamine-derived “coal tar dyes”.
Colour Index
In terms of the “ ’C.I.’ followed by five digits”, Suzuki and cohorts are simply out to lunch. “C.I.” stands for “Colour Index”, a long-standing reference work listing all synthetic dyes, and giving each a name and a number. Some of those names start with the word “Natural” but these compounds are not found in nature. Much later, dyes actually found in nature were added to the index, starting with number 75100 , but are limited to those with commercial use. There is no other meaning to the C.I. number whatsoever. Therefore, the idea to associate the existence of a “C.I.” number for any substance with the potential for any effects, adverse or beneficial, is simply nonsense.
What makes a Dye?
By their nature, dyes absorb light of a particular wavelength of light (e.g. green) but not that of another wavelength (e.g. red). That is what makes it a dye. Any chemical which absorbs a band of light in the visible (to the human eye) region, requires a number of “conjugated bonds” (i.e., -C=C-, -C=N-, or -N=N-). For example, the (natural) orange colour of carrots, produced by the compound carotene has eleven such “-C=C-” bonds. It is a healthy part of our common diet. In WWII, airplane pilots in the UK were forced to eat copious amounts of carrots, in the belief that the carotene would improve their night vision. The belief was later shown to be mistaken - but you still should eat your veggies.
Heavy Metal Contaminants
The Guide’s statement “Potential to cause cancer and can be contaminated with heavy metals toxic to the brain” is another example of misunderstood facts. The backgrounder to this pamphlet, available from the DSF website goes even farther by including aluminum salts. It states: “.. these colours may be contaminated with low levels of heavy metals and some are combined with aluminum substrate. Aluminum compounds and many heavy metals are toxic to the brain. “
Even if trace amounts of heavy metal ions were present in such dyes, they would be without any consequence to your health. The ions would not migrate through your skin and skull to affect your brain. You would have to actively ingest large amounts of such dyes to be exposed to any toxic effects from the metal ions – if present at all. Also, Suzuki and friends seem to be totally unaware that we have been using aluminum cooking pots for a century or so, that almost any body perspirant contains a high percentage of aluminum salts, and that aluminum salts are widely added to bread to retain moisture.
Summary
The Suzuki organization is trying to cash in on the widespread fear of “chemicals” with strange names, numbers and implied associations. This fear-mongering is bordering on superstition. If you prefer facts over fiction, my I suggest: Rather than sending your money to that organization, RECYCLE their GUIDE and BUY a copy of my book
CONVENIENT MYTHS instead.
