Someone on Twitter spoke on this, so I cant' confirm its accuracy.
They said that the reagents for this are usually made in China. As soon as this paper was published, labs in China bought out the reserves and they became hard to source in the West.
Weren't the raw materials lead, copper, sulfur and phosphorous or something like that? Seems hard to to buy out elements that are so common in industrial and chemical processes.
There's nothing exotic in there that you can't just buy from Spectrum Chemical (though they need to know you and that you're not likely to be making methamphetamine).
