Pine tar toxicity.
So there's this EU "scientific" committee opinion ... don't trust it.
On the medicinal herblist:
DJ: "Allow me to add that I haven't yet found information that definatively connects pine tar soap use with skin cancer."
and, in reply to that:
Susan: "Um, lessee...OK, here's the link to the article I read".
That paper is the "Opinion of the Scientific Committee on Cosmetic Products and Non-food Products intended for Consumers concerning Wood Tars and Wood Tar Preparations."
First, a personal bias: I dislike committee opinions, intensely. Committees are usually dumber than their dumbest member, and they're totally anonymous: you can't hold anybody responsible for what this dumb beast decides to put on paper.
Also, I like pine tar (I've even made some), and I like pine tar salves (I've made those, too), shampoos, cough drops and so on. And I think that pine tar, as a preservative of, say, wooden boats, is vastly better than any newfangled toxic paints or pressured impregnations.
That being out of the way, here's my critique of this committee opinion:
They were asked to answer this question:
"Are wood tar and wood tar preparations safe to be used in cosmetic products?"
Keep that question in mind.
Quoting from the paper:
"the PAH (polycyclic aromatic hydrocarbons) content differed in two different preparations of Rice bran tar and Pin tar. The results suggest that the PAH content may vary both with the source of the tar as well as in different preparations of tar."
Hmmm. (And, since when is rice bran a wood?)
"The skin drugs were dissolved in acetone and applied to back of mice, interscapular region, 3 times a week for whole span of the experiment."
So - how different is acetone vs. vegetable oil, as a solvent of tar? I posit that acetone in itself is drying and damaging to the skin, thus helping things along quite a bit.
Also, the table on page 8 states that pine tar tumours first appeared after 33 weeks (of those three-times-a-week applications). That's 8 months and a bit. They started with 60 mice, at 33 weeks 31 were left in the pine tar group, and from week 33 to the death of the mice (or to week 90, when the experiment was terminated), 7 got skin papillomas (are those dangerous?), 2 got squamous carcinoma, and (those same?) 2 also got lung adenoma.
Rice bran tar (pityrol), oil-extracted soybean tar (glyteer) and colorado shale oil (metashal) were vastly more dangerous to these mice. Ichthammol (a distillate from mineral deposits), also included in the table, gave other cancers, not squamous carcinomas.
So, since when is soybean a wood, and since when are metashal and ichthammol wood tars?
The committee then lumped all of these together, and draw their conclusions from the total ... I think it's a case of somebody or other lobbying against pine tar.
And I think that if they had made a paper on just wood tar, like they were asked to, instead of including things like rice bran tar, shale oil, creosote and so on, they'd have been laughed out of the room for trying to ban its use.