I soak my green sticks in a solution called Pentacryl. At my age, anything that might cause me to develop cancer in the next 20 years probably isn't what's going to kill me. The Material Safety Data Sheet (MSDS) that the source provides does not look like the typical MSDS required in the USA of most industries selling or transporting chemicals. It does say that it isn't toxic. However the typical MSDS shows toxicity, carcinogenicity, and mutagenicity data.
I still use Pentacryl, but I recommend examining the MSDS for all chemicals used and then make your own judgment regarding the health risk.
I still use Pentacryl, but I recommend examining the MSDS for all chemicals used and then make your own judgment regarding the health risk.