SALT LAKE CITY (AP) — Several Utah vape shops sued the state’s Department of Health over its emergency rule restricting the sale of flavored e-cigarettes amid a national outbreak of lung damage linked to vaping.

In the lawsuit filed Monday, retailers claimed there is no evidence to suggest flavored e-cigarettes are causing lung damage and that the new rule could hurt business.

Recent cases of lung damage, they argued, are instead caused by “these persons’ use of black-market THC cartridges,” according to the lawsuit.

The rule, which took effect Monday, bans general tobacco retailers including grocery stores, pharmacies and gas stations from selling flavored e-cigarette products. All tobacco sellers are required to post notices about the danger of vaping unregulated THC, the high-producing ingredient in marijuana that’s been linked to most lung-damage cases in Utah.

All vape shops involved in the lawsuit are general tobacco retailers that can no longer sell flavored vape products under the rule.

The retailers said the health department enacted the rule without public comment and that the ban would cause “irreparable harm to their business reputation” to the point that they would be “forced to close their businesses.”

Utah has been hit especially hard in the national outbreak. State health officials have identified 98 cases and one person has died. Many patients are in their 20s and 30s.

“We know many young people who vape THC initially vape nicotine, especially flavored nicotine,” Joseph Miner, executive director of the state health department, said in a recent statement. “Moving these products to age-restricted specialty shops will restrict young people’s access to them and can reduce the number of users who eventually move on to vaping THC.”

Tom Hudachko, a department of health spokesman, declined to respond to the lawsuit’s claims but said stopping the outbreak is the top priority. He said reducing young people’s access to nicotine vaping and THC products is key.

The U.S. has seen an explosion in youth vaping in recent years, with critics saying the industry is marketing flavors that appeal to teens.

President Donald Trump’s administration has proposed a sweeping ban on e-cigarette flavors. Several states have already done so.

Nearly 1,500 people across the country have become sick from vaping, and 33 people have died, the Centers for Disease Control and Prevention has reported.

Symptoms include coughing, shortness of breath, chest pain, fatigue, nausea and vomiting.

Health officials throughout the country are advising people not to use any vaping product until the cause of the illnesses is better understood.