The U.S. Food and Drug Administration is working to develop strong product standards for electronic cigarettes and other nicotine delivery devices that will protect public health and enable the agency to withstand legal challenges, its tobacco chief said on Wednesday.

Mitchell Zeller, director of the FDA's Center for Tobacco Products, said the agency is exploring potential product standards in the areas of addiction, toxicity and product appeal as it prepares to gain regulatory authority over electronic cigarettes and other nicotine-delivery devices.

The establishment of product standards is one of five priorities for the division over the next few years, Zeller said, outlining them publicly in the most comprehensive manner to date.

They include putting in place regulations for approving new products and monitoring them after they reach the market, ensuring that the agency has in place a strong compliance and law enforcement presence in every state, public education and the formulation of an FDA-wide nicotine policy that recognizes some products are less risky than others.

The agency is formulating product standards at a time when the benefits and risks of e-cigarettes remain the subject of intense debate.

"It's not the nicotine that kills half of all long-term smokers, its the delivery mechanism," he said at a lunch in Washington, D.C. organized by the American Legacy Foundation, an anti-tobacco group. . "We have to recognize some of these realities and figure out how they can impact regulatory policy.".

The 2009 Tobacco Control Act gives the FDA authority, as long as it has scientific evidence to support the policy, to ban or restrict ingredients and compounds in a particular product, though the agency will need to issue a new rule to act on its authority.

In April the FDA proposed rules that would ban the sale of e-cigarettes to people under the age of 18 and subject the $2 billion industry to federal regulation for the first time. The proposal would not restrict flavored products, online sales or advertising, disappointing public health advocates who argue they attract children.

Zeller said that while it is never a good thing for a young person to inhale nicotine, further research is needed to assess the net impact of e-cigarettes on the overall health of the population and that it is important to have "an open mind" about the potential benefits of emerging technologies.

"We share the concerns about the marketing of e-cigarettes to kids," he said, "We share the concerns that flavors certainly look like they would be appealing to kids; but let's not lose sight of the bigger picture here--tobacco use remains the leading cause of preventable death and disease principally because of the ongoing use of products that burn tobacco.

The FDA is also considering regulating menthol, but Zeller said he could not estimate how long it will take to formulate a proposal. The agency received 176,000 comments from the public on the matter.

"We are seriously considering all the comments as we consider our regulatory options," he said. "We can only go as far as the science will take us."