The Obama administration has failed to finalize federal regulations for e-cigarettes nearly a year and a half after a proposed rule was issued, which has public health advocates clamoring for a decision to quickly rein in the growing industry.

"Right now we have a wild west market of products with e-cigarettes," said Vince Willmore, spokesman for the Campaign for Tobacco Free Kids. The group was part of 31 organizations that wrote to President Obama in April calling for the regulations to be finalized.

But the e-cigarette industry believes the delay is due to legal issues surrounding whether the FDA has the authority to regulate the products.

The Food and Drug Administration issued a proposed rule in late April 2014 outlining several regulations for the burgeoning e-cigarette or "vaping" industry. The rule includes a ban on sales to minors and subject new tobacco products to FDA review, and a requirement for producers to register with the agency and back up any health claims they make.

The FDA has no update on when the final rule will be released, but said that it would be subject to further review because of its significance.

"Rulemaking is a complex process," agency spokesman Michael Felberbaum told the Washington Examiner on Friday. Adding to the complexity are the more than 135,000 public comments that the agency has to review.

Normally, the agency would review the rule and then put out a final one. However, the e-cigarette rule was deemed "significant" by the federal government. That means the White House's Office of Management and Budget must review the rule before it is published.

This can sometimes delay the process. For example, the White House took several months to review a rule that required barcodes be put on medical devices, much to the consternation of the medical device industry. Additionally, the White House sometimes lets other federal agencies that may have an interest in a significant rule review it.

Advocates have said that a final rule is needed soon because there is no federal oversight of e-cigarettes. And with the federal government not filling the void, many states have taken up the issue of sales to minors on their own. At least 46 states and two U.S. territories prohibit e-cigarette or alternative tobacco product sales to minors, according to August 2015 data from the National Conference of State Legislatures.

A federal ban is needed for the remaining states, especially as e-cigarette use has exploded among minors, Willmore said.

E-cigarette use tripled from 2013 to 2014 for middle and high school students, according to the Centers for Disease Control and Prevention. It was also the first time since 2011, when data on e-cigarettes was first collected, that such products surpassed traditional cigarettes in use, CDC said.

Willmore said restrictions on marketing are also urgently needed.

"Right now [there are] no restrictions to marketing and flavors that appeal to kids," he told the Washington Examiner. Regular cigarettes have a prohibition on event sponsorship, free product sampling and flavoring cigarettes so they taste like candy or food, Willmore said.

Oversight is not just needed to protect children, but also adults. Willmore said there is no oversight of marketing bogus health claims, such as whether e-cigarettes are a healthy alternative to traditional cigarettes.

But that claim is hotly debated among activists and e-cigarette supporters. The e-cigarette industry points to numerous studies that argue the products are healthy since they don't burn tobacco like a traditional cigarette. Instead, an e-cigarette converts liquid nicotine into a vapor.

The Centers for Disease Control and Prevention, however, did a study last year that said calls to poison centers involving e-cigarette liquids rose from one per month in September 2010 to 215 a month in February 2014.

Industry has adamantly opposed sales of e-cigarettes to minors, said Phil Daman, CEO and president of the Smoke Free Alternatives Trade Association. Daman is also a founding attorney of Daman and Associates.

Banning marketing of flavors is another matter.

"We believe that flavor profiles are important to the adult consumer because the flavor profile is what keeps people using the product once they stop using tobacco," he told the Washington Examiner.

Daman said he wasn't surprised by the FDA's long delay in getting out a rule.

"The FDA knows it is not allowed to expand its jurisdiction to vapor products," he said.

The agency received the authority to oversee tobacco products in the 2009 Family Smoking Prevention and Tobacco Control Act. But Daman contends that same authority doesn't extend to e-cigarettes.

He said the law allows the FDA to address public health crises created by the tobacco industry, but said the e-cigarette industry is "very different."