(Reuters) - Proposed tariffs on U.S. imports from China of electronic cigarettes, known as vaping products, could not come at a worse time for the industry.

Electronic cigarettes are on display at The Vapor Spot vapor bar in Los Angeles, California March 4, 2014. REUTERS/Mario Anzuoni/File Photo

New levies would increase prices just as the industry is facing slowing growth and as it begins to add new health warnings to packaging.

The Trump administration has threatened 25 percent tariffs on $200 billion worth of Chinese imports, including vape devices and parts, in addition to tariffs on $50 billion already imposed.

As a result U.S. vape manufacturers, who depended on China for 91 percent of imported vaping products in 2016, find themselves caught in the middle of a growing trade war. Vaping which is often cheaper than smoking, has surged in popularity in recent years. Viewed as a healthier alternative to smoking, users inhale steam from the nicotine-filled devices, rather than burning cigarettes with byproducts of paper, tobacco and a range of other chemicals.

The potential negative impact of tariffs represent just one example of how the rapidly expanding trade war between the U.S. and China can affect whole industry sectors, causing job losses and other financial pain.

The tariffs could drive up the price of a vape by about 15 percent, according to industry estimates. This would be particularly painful for an industry where consumers are highly sensitive to rising prices. Nielsen Tobacco report estimates retail sales of the U.S. vapor market will be about $5.5 billion in 2018.

A study in the journal Tobacco Control estimated a 10 percent price increase in e-cigarettes would reduce sales by between 12 percent to 19 percent. The study noted that because many vapers are experimenting, rising prices could curtail future use.

“Margins on products are already low, to maintain margins we’d have two choices, raise prices or cutting employees’ hours,” said Matthew Milby, who owns two Maryland vape shops under the name Smoke Free Nation. He predicted some shops would be put out of business.

Two of the biggest companies, Juul Labs and VMR Products, are among companies with products that will be hurt by the tariffs. Juul led the market growth last quarter, and held 68 percent of the market share according to a June Nielsen Tobacco report.

Industry experts predict the tariffs could affect virtually all vape and e-cigarette products, and hit the industry’s smaller firms hardest.

Jan Verleur, chief executive of vape maker VMR, is worried tariffs, which he will likely have to pass on to consumers with a 10 percent to 15 percent price increase, will reduce consumers access to the products since an estimated 70 percent of the company’s products would face the extra levy.

Euromonitor International’s Head of Tobacco Research, Shane MacGuill, said the tariff would have a “significant detrimental impact on the vapor product industry.”

Euromonitor’s year-to-year data shows the market’s growth has been slowing, for smokeless tobacco and vapor products. From 2016 to 2017, the market grew just 9.3 percent, compared to 22.5 percent in 2015 to 2016.

Juul’s industry-dominating devices and pods will fall under the tariffs. The company declined to disclose what portion of products could be effected, or if it would increase prices.Ramping up U.S. manufacturing of e-cigarettes, which were invented in China, would be difficult until there is a clearer picture of the developing regulatory environment, including new labeling requirements and increased Food and Drug Administration regulation in 2022.

The United States also has too few workers with the specific technical expertise to make vaping products.

In comments to the U.S. Commerce Department about the proposed tariffs, Juul’s chief legal officer Gerald Masoudi said no manufacturers located outside of China would be willing or able to supply the volume of devices Juul needs.

Geoff Habicht, president of SV3, an American-based company that manufactures its products in China, predicted a $40 product could increase to $45 or $50, and a $10 refill could increase to $12.50.

SV3’s tentative plans are to take on some of the increased cost for a quarter rather than pass them on to the consumer as the company weighs options.

But, Habicht said consumers could end up seeing a 14 to 25 percent price increase across products. He also is pushing his suppliers to absorb some costs.