Here is a link to the text of S.142 (passed in the U.S. Senate December 2015, and by voice vote in the U.S. House of Representatives 1/11/2016) and the relevant Code of Federal Regulations (CFR). If signed by the President, this will be the first Federal legislation EVER in the U.S. directed specifically towards the electronic cigarette industry.
To require special packaging for liquid nicotine containers, and for other purposes.
Title 16 CFR (1700.15 & 1700.20): https://www.gpo.gov/…/…/CFR-2012-title16-vol2-sec1700-15.pdf
Credit to Kevin Skipper – Vista Truth