OK, that coffee cup case had merit. Although there is still dispute about what the appropriate and safe temperatures for delivery of coffee are. Some want it delivered very hot so that it will be drinkable when they reach their destination. Others have a low tolerance for hot liquids and want to drink it immediately.
Many of the warnings don't.
I love the California one. This store may contain chemicals known to cause cancer. Or the related one, also California related, that causes wood to be labeled as containing chemicals known to cause cancer. Not treated wood, just plain kiln dried timber. Which has residues of creosote, turpentine and other horrible things. I am waiting for a sign a the National Parks entrances letting you know that the wonderful smell is caused by volatile hydrocarbons with known carcinogenic properties. Danger, do not go to Lake Tahoe, Sequoia, Kings Canyon, Yosemite, Muir Woods or any of those other dangerous places.
This nonsense is not uniquely from the US. I will repeat over and over the RFP received once from a European nation for a piece of electronic gear. Required that it be certified to contain no hazardous materials including Lead, Cadmium, Chromium and COPPER! I suppose they wanted the whole thing made with silver and gold, along with assurance that there was no Silver Nitrate residue.