I can't think of an equally concise but more accurate phrasing so long as a reference to California remains, but maybe brevity isn't such a high priority.
The California notices are one of the only examples of it being put in your face everywhere
There is a whole philosophical bent about what "good" intentions might be which is way off topic.
When the side effects for ibuprofen read similarly to those of far more dangerous prescription drugs, then they're really not helpful
There are of course other problems as well, including lack of context (do you need direct contact, exposure over time, etc), and lack of a requirement to list the particular chemicals. As a result, there's no actionable information and the signs are entirely devoid of meaning.
The light bulbs/tubes/LEDs also contain a number of P65 materials, as do all the electronics...
We know that if the chemicals are there, we have to have the sign. And we know that the chemicals are everywhere.
So what benefit does the sign bring?
None.
Not actually true.
https://leginfo.legislature.ca.gov/faces/codes_displaySectio....
Companies are choosing to CYA because if they're sued the burden of proof is on them.
And it's not just coffee you see these labels on. You see them all sorts of random places, and often not in a way that helps you make informed decisions.
I've seen prop 65 warnings in hotel rooms, likely due to lead pipes in the toiletry. The application, and to an extent the compounds included, are a little overkill. Keeping that in mind, It would be worth scrubbing through the article and seeing what the components are that are not just "California Carcinogens". That's what would be the really valuable information here.
I am sure a followup study will be done to see if this is actually a problem in the USA in 2021.
The article is published here (Open access) : https://www.sciencedirect.com/science/article/pii/S016041202...
Edit: I found this news article from 2003 discussing the issue of carcinogenic new car smells and how manufacturers were trying to eliminate the the dangerous smells while simulating what consumers expect a new car should smell like:
https://www.caranddriver.com/features/a15133792/new-car-smel...