If that were the case, we'd be in serious doo-doo.
FDA identifies 92 events of overheating/fires/explosions from 2009 to 2015
There have been enough incidents where the government could have stepped in. And if you thought government regulation was bad now, that's nothing after CPSC gets done with something (think what happens after OSHA gets involved with safety issues).
Wonder what the circumstances are for CPSC to get involved vs something being required to have a UL listing. I see that there is a UL listing for lithium batteries that's already been put out.
UL (safety organization) - Wikipedia, the free encyclopedia