seasoning: polymerizing oil

No.12382343 ViewReplyOriginalReport
how come some say to avoid flaxseed oil because it releases carcinogens and what not
is there actually a solid scientific study on the most effective and healthy way to season a carbon steel / cast iron pan?

https://www.cooksillustrated.com/how_tos/5820-the-ultimate-way-to-season-cast-iron