I’ve said it here many times. Our ability to produce chemicals far exceeds our ability to test for side effects. It takes years, and in many cases decades before we figure out what many chemicals actually do.
Formaldehyde is everywhere. Not only is it now linked to cancer, but it causes many problems for those who are chemically sensitive as well.
This is why I oppose virtually all applications of chemicals in the environment (including chemicals that kill fish so native fish can be planted). We simply don’t know, and won’t find out until our testing technology catches our production technology.