They may have been the first in the e-liquid world, I'm honestly not sure. However, this has been studied by tobacco companies decades prior: https://www.degru

They may have been the first in the e-liquid world, I'm honestly not sure. However, this has been studied by tobacco companies decades prior: https://www.degruyter.com/downloadpdf/j/cttr.1983.12.issue-2/cttr-2013-0524/cttr-2013-0524.pdf https://www.degruyter.com/downloadpdf/j/cttr.1983.12.issue-2... Also as a possible correction, they're not adding benzoic acid to nicotine salts, rather they're using benzoic acid and freebase nicotine to make nicotine benzoate - which is a nicotine salt. I may be misunderstanding your phrasing though, if I am I apologize.