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by graphe 960 days ago
Funny this was the other discussion it being contaminated. https://news.ycombinator.com/item?id=38139011

Wikipedia suggests its toxify is overblown. https://en.wikipedia.org/wiki/Lead(II)_chromate

>Despite containing both lead and hexavalent chromium, lead chromate is not particularly toxic because of its very low solubility. The LD50 for rats is only 5,000 mg/kg. Lead chromate is treated with great care in its manufacture, the main concerns being dust of the chromate precursor. "Extensive epidemiological investigations have given no indication that the practically insoluble lead chromate pigments have any carcinogenic properties".

3 comments

Turmeric is trending in the Hacker News Collective Conscious.

It could have been any word.

The news piece was "Indians caught using lead as food colorant".

In addition to lead chromate, in some instances metanil yellow is also used. It can also be potentially neurotoxic and hepatotoxic [1].

I found a spice producer's site that contained some instructions of how to determine if it's adulterated [2]:

Metanil Test: To test for the presence of metanil yellow, place a pinch of turmeric powder in a test tube, add a few drops of strong hydrochloric acid, and violently shake it.

If the solution becomes pink, this indicates the existence of metanil. Consuming turmeric powder that is high in metanil will make you feel nauseated, create stomach problems, and cause food poisoning.

Lead Chromate Test: To test the presence of lead chromate in turmeric powder, mix a teaspoon of turmeric powder with water. It will instantly leach streaks of water-soluble colour into the solution, indicating the presence of lead chromate.

[1]: https://en.wikipedia.org/wiki/Metanil_Yellow

[2]: https://www.vasantmasala.com/blog/how-to-check-adulteration-...

Because it has low solubility it will be less toxic compared to a more soluble form of lead, but it is still highly toxic and there is no safe dose. It has been implicated in numerous documented cases of lead poisoning from adulterated turmeric and you wouldn't want to be consuming it.
did anyone source a reliably pure one
reliably pure lead chromate?
turmeric
Those are synonyms.
?
I was joking :-/