Why is it so hard to ban chemical substances whose pathogenic properties have been well-documented?

The International Agency for Research on Cancer (IARC) works to establish proof of carcinogenicity. But as this yearslong study shows, the actions of the experts at this dedicated research institution are hindered: they cannot structurally evaluate the quantity of substances in circulation; their methods of analysis obscure entire categories of toxic agents; they are caught up in power struggles among scientific, political, and economic actors that keep needless controversies endlessly alive.