In the midst of the pre-holiday frenzy, it can be helpful to pause and take a moment to remember the important thing: Life is fragile, and Christmas is full of dangers. Each year, emergency rooms fill with people who have fallen off ladders while hanging lights, or have been felled by falling Christmas trees, or have just done something stupid after too much eggnog.

Take it as a small comfort, then, that at least your tree decorations aren’t poisonous. That wasn’t always the case: Until the Food and Drug Administration intervened in the 1970s, tinsel was made of lead.

As The Wall Street Journal has reported, some people trace decorative tinsel to the 15th century, while others believe its use began in the mid-1800s, when people began to hang metal strips on their Christmas trees to pick up the surrounding candlelight. Either way, it didn’t really catch on in earnest among U.S. consumers until manufacturers began to mass-produce it around the beginning of the 20th century.

Previously, tinsel—which gets its name from the Old French word estincele, meaning sparkle—had been made of silver, making it affordable to only a few. But at the turn of the century, alternatives made from cheaper metals like aluminum and copper turned a luxury good into a ubiquitous holiday decoration. These materials also didn’t tarnish the way that silver did, meaning they could be reused each year without dulling the shine.

But each had its own disadvantages, too. Copper enjoyed a brief run as tinsel before World War I upped the demand; aluminum tinsel, meanwhile, proved itself to be incredibly flammable—not really a trait you want in something designed to reflect candlelight.

So tinsel manufacturers remade their product once again. This time, they settled on lead. And they stuck with it until the early 1970s, when a growing awareness of the risks of lead exposure forced the FDA to step in. Because the direct effects of exposure to lead tinsel hadn’t been fully assessed, the agency didn’t have enough evidence to outright declare it a health hazard. Instead, it worked with customs to prevent any imported lead tinsel from entering the U.S., while leaning on the domestic tinsel industry to stop using the material.

“We got back to the industry and said, ‘You haven’t got a saleable product anymore. You might as well get out of the lead business,’” Malcolm Jensen, then the director of the FDA’s Bureau of Product Safety, told the Associated Press in 1972. But the change wasn’t widely publicized at the time, he added, because consumers were loyal to the tinsel they knew: “We feared that many people preferring the lead variety would stockpile it.”

And thus ends the story of lead used in tinsel. But elsewhere, the metal was still omnipresent: It would be another six years before the FDA banned all lead house paint in 1978, and another 16 before Congress passed the Lead Contamination Control Act, which authorized the Centers for Disease Control and Prevention to ramp up its lead-poisoning prevention campaign.

Today’s tinsel is made of plastic—a pale imitation of the old lead stuff’s heft and shine, according to some die-hards, but at least the Christmas tree’s a little safer than it used to be. For a dose of holiday neuroses more fitting to these modern times, the U.S. Consumer Product Safety Commission recently posted this video showing how quickly a cozy Christmas-tree’d living room can turn into a fiery inferno. Watch your fire safety, and make good choices, and say it with me: Life is fragile, and Christmas is full of danger.

Happy holidays!