Single-use plastic straws, bags and coffee pods have captured the attention of the public and legislatures looking to ban products that wind up littering the landscape. But e-cigarettes have also begun to show up on streets and shores, presenting the challenge of how to deal with litter that is part-recyclable and part-hazardous waste.

"We started seeing them a number of years ago," said Cindy Zipf of Clean Ocean Action. "Most of us didn't even know what they were."

E-cigarettes, introduced to the U.S. market in 2006, have seen an explosion in growth since 2014. More than 2 million middle and high school students are now regular users.

Unlike the typical tobacco cigarette made of paper, tobacco and a filter, each e-cigarette has five components — residual nicotine, plastic, lithium batteries, aluminum and fabric, each of which has to be disassembled and recycled separately.

The ideal solution would be for the manufactures to take the parts back, said Scott McGrath, an environmental planning director. That seems unlikely; some e-cigarette manufacturers recommend that smokers just pitch the empty products.

TerraCycle is one of the few companies globally that accepts all parts of e-cigarettes."They are far more difficult to recycle than regular cigarettes because of the number of components," said Ernel Simpson, global vice president of research and development for TerraCycle.

If e-cigarette materials are left in the environment, it is possible they will seep into the soil and eventually into the water table, Simpson said. The small pieces may be a choking hazard to children and wildlife.

The company sells collection boxes that range in cost from $100 to $250. About 50 percent of the business comes from California, which enacted the Safe Drinking Water and Toxic Enforcement Act in 1986, Simpson said.

"Using it once and tossing it is not sustainable," he said.