Non-toxic pigments part II

Aside from the common tendency to conflate non-toxic materials with sustainability, there is also the natural concern over one’s personal health and safety when using toxic pigments based on lead and cadmium and so on. Personally, and I am not alone in this, I think the aversion to using toxic pigments can at times be taken to extremes – and I have to admit, the first time I used lead white I was a bit trepidatious. But, as I knew, irrationally so: common sense indicates that most pigments, even lead-based ones, are perfectly safe when bound up in oil, as long as one takes reasonable precautions, such as not eating or drinking in the painting studio, washing one’s hands well after painting, cleaning the palette carefully, disposing of rags responsibly, etc. And that’s what I do now. In fact, I’d say the addition of lead white to my palette has made me safer than before, because of these habits I’ve developed. I used to have cadmium red on my hands all the time; now, I respect my materials and work more cleanly.

There are, however, cases in which a greater concern for the toxicity of pigments is well warranted, and one of those is when an artist is working with them in their raw powdered form. Dry pigments have a much greater chance of getting into one’s body, since the pigment particles can and do drift into the air, and from there they can be breathed in, or can settle onto surfaces in thin layers that might not be readily apparent, there to be picked up by fingers or utensils. I work with powdered pigments all the time, but I won’t work with lead in any of its dry pigment forms, nor cadmium, mercury, or cobalt. The thought of getting lead carbonate dust around the house is intolerable to me.

In addition to pigment nuts like me, there are also many artists who regularly work in egg tempera. Egg tempera, properly speaking, is not available as a tubed paint because it spoils so quickly, so artists of that medium must grind their own paints from dry pigments and use them fresh. (The “egg tempera” tubed paints offered by companies like Shiva are actually tempera grassa, whose binder is an emulsion of egg yolk and a drying oil.) Those artists tend to be more aware of the toxicity their materials, since they must work with them more intimately. There is also the case of women who are pregnant. I understand the desire for greater-than-normal safety measures in that situation, so pregnant women may be more concerned about even tubed paints, wanting to take no unnecessary chances at all. And rightly so.

So, which pigments are non-toxic, if one is really concerned about such a thing? Well, earth colors and iron oxides are all pigments that might fairly be considered non-toxic – it’s just dirt after all – except for the raw and burnt umbers, which are partly manganese oxides (manganese is toxic). Next up is titanium white, which is definitely on the safe list. It is used in toothpaste, sunscreen and lip gloss. Zinc white is safe as well: it is used in calamine lotion and in supplements. If you’re working in watercolors or pastels, chalk works great as a white too. For blacks, bone black should be fine.

Ultramarine blue is very safe. This color has actually been approved for use in food: that blue icing on your kid’s birthday cake is probably ultramarine (the white frosting is titanium white). There are other ultramarines as well, green, violet and pink, and all of them should be safe.

Homemade lake pigments, such as those made from madder, cochineal or weld, are fairly non-toxic (only “fairly,” because their main component is aluminum hydroxide, which is iffy). However, you should be careful of other ingredients might be included in commercial artists colors – some commercial natural lake paints may contain tin, which is toxic. Indigo, another natural organic pigment, has low toxicity.

Some others: Chromium oxide and viridian, though made from the very toxic potassium dichromate, are in their green pigment form chromium(iii), which is stable and is included in nutritional supplements. Egyptian blue, though made from copper, is supposed to be extremely stable and insoluble. Prussian blue is borderline: though it does contain a cyanide component, it should be stable unless heated. Nevertheless, from what I’ve read in forums, there is less than 100% agreement by chemists on the stability of prussian blue in stomach acid. And you really don’t want cyanide floating around in your system.

Here is another list concerning pigment toxicity and pregnancy posted on the egg tempera forum by artist Alessandra Kelley. I wouldn’t have thought synthetic organic pigments to be directly toxic, but Kelley may change my mind. Here’s a link to the article.

Please do keep in mind with this stuff that I am not an expert, and the information I’ve written above is based only on my own informal research. To put it plainly: I don’t really know what I’m talking about here. If educating yourself about the toxicity of pigments is important to you, then you certainly shouldn’t take my word for anything, but do your own research instead. At the end of the day, I think the only pigments that can be considered truly non-toxic are those that are classified by the FDA as “Exempt from Certification” in food and drugs. The artists’ pigments among those are: ultramarine blue; carmine; iron oxides; saffron; titanium dioxide; calcium carbonate (chalk); chromium oxide greens; logwood; and zinc oxide. FDA It’s worth noting that there are some copper compounds included there: copper is certainly somewhat toxic, but it ain’t as bad as all that. The list of cosmetics should be excluded from consideration here, since they are meant to be taken externally; you’ll notice that lead acetate is in that list (it’s used in hair dye), but I don’t think anyone would call lead acetate a non-toxic pigment.


Tags: , , , ,

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: