The BART Board of Directors is expected to vote today on whether to ban the use of electronic cigarettes on trains and in stations.
BART spokesman Taylor Huckaby says he expects the board to pass the ban.
"The board has had a number of complaints about people that are smoking these e-cigarette or vaping devices on the trains. And so we, after some consideration, have decided that we would like to have a consistent nonsmoking experience on all transit property," Huckaby says.
The four counties that BART operates in -- Contra Costa, Alameda, San Francisco and San Mateo -- already have restrictions on using e-cigarettes in public places. Huckaby says the proposed ban would fill in any gaps in enforcement and further clarify the agency's smoking policy.
"We want (our passengers) to be able to breathe a smoke-free atmosphere, whether that's nicotine vapor or actual smoke," he says.
E-cigarettes are often marketed as a safer alternative to smoking. But a UCSF study last year found toxins like formaldehyde in the vapor from these devices, although at lower levels than conventional cigarettes.
The study's authors also wrote that e-cigarette use has a negative impact on lung function in the short term, and that bystanders can "absorb nicotine from passive exposure" to the e-cigarette vapor.
The same study found that using e-cigarettes isn't very effective in helping people quit smoking -- smokers in the study were a third less likely to quit than smokers who did not.