The US Food and Drug Administration announced a comprehensive, multi-year plan Thursday to stamp out the leading cause of preventable disease and death in the country—tobacco use.

The agency intends to reduce the amount of nicotine allowed in traditional combustion cigarettes with the goal of making them “non-addictive.” At the same time, the FDA will delay regulations on electronic cigarettes and other newer products to “afford the agency time to explore clear and meaningful measures to make tobacco products less toxic, appealing, and addictive,” the agency said in a press statement.

“A key piece of the FDA’s approach is demonstrating a greater awareness that nicotine—while highly addictive—is delivered through products that represent a continuum of risk and is most harmful when delivered through smoke particles in combustible cigarettes,” the agency wrote.

The announcement sent shockwaves through the industry—tobacco company shares plummeted.

"It’s hard to overstate what this could mean for the companies affected: non-addictive levels of nicotine would likely mean a lot fewer smokers and of those people who do still light up, smoking a lot less," Neil Wilson, a senior market analyst with ETX Capital in London, told Reuters.

Smoking and tobacco use is already at historic lows for adults, teens, and children. Only about 15 percent of adults smoke and only about 11 percent of high school students are lighting up. Still, as the FDA points out, tobacco use remains the leading cause of preventable deaths in the country, leading to more than 480,000 early deaths each year.

The FDA plans to “open a public dialogue” about lowering nicotine levels in cigarettes and signaled an intention to critically examine flavored tobacco products, thought by many to be geared toward hooking kids.

But the agency wants to pull back regulations to have new tobacco products that entered the market after February 15, 2007—which includes most e-cigarettes—submit to rigorous review. The rules would have forced manufacturers to go through the review within two years or face having their products yanked off the market. The agency now says e-cigarette companies have until August, 8, 2022 to submit to review and can keep their products on the market in the meantime.

The agency also announced it will establish “foundational rules” to make the FDA review process smoother and more transparent for manufacturers while it upholds its public health mission.

In an accompanying statement, FDA Commissioner Scott Gottlieb said: