https://reptox.cnesst.gouv.qc.ca/pages/fiche-complete.aspx?no_produit=268722&nom=Acide+ligninesulfonique Canada French acids lignin lignosulfuric acid toxicological data sheet
--- https://www.anses.fr/fr/system/files/DPR2011sa0207.pdf 2011 France French scientific and technical information chelating agents edetic acid lignosulfuric acid lignin 3-methylpyrazole dicyandiamido guanidines pyrazoles 1,2,4-triazole triazoles edetic acid N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid