This is a California Prop 65 warning (not to be confused with project 365!). They are all over the place here (in public venues, on rental cars, ...) and are pretty much completely useless. Let's review what it does: It informs me that somewhere in the general vicinity are materials that might or might not be harmful for me in some way. There are approximately two cases of such materials.
One, things that I am likely to ingest or are otherwise sufficiently likely to cause such harm to me. I would argue that materials of considerable and imminent danger to the public should be banned altogether (example: Asbestos). Or, if they can't be avoided because they really are everywhere, then a vague warning in distinct spots doesn't help because the individual has no way to protect themselves against it, other than locking themselves into a cleanroom.
Two, things that I am unlikely to suffer harm from, unless I abuse items for uses different than their intended purpose. For example, I chew the glue off my car's dashboard, or snort paint chips off the wall at my local train station. One could argue, in such a case possible birth defects are the least of my problems.
That being said, Wikipedia mentions that the 1986 proposition itself was quite successful so far in publishing and subsequently reducing or eliminating exposure of specific harmful chemicals. I appreciate that.
The ubiquitous warning labels, however, are, at best, a Californian curiosity (and to the locals, a mere addition to the background noise), and at worst a 1-dollar "band aid" that has been applied for 25 years now instead of removing truly harmful materials from the public space.