you can buy chemicals online for all sorts of purposes but they must have safety label and not be sold for human consumption and sites doing this are left alone.
however if some company was blatantly selling dangerous chemicals no questions asked to make a bomb or deliberately pollute the environment or poison someone, and a another site was advocating these activities / giving instructions and saying “you can get the stuff from this website and not get noticed” both the sites involved will get in trouble.
you do get free speech in Europe but not a license to harm people.
