The Razor was the first hit toy of the new millennium. In 2000, Razor sold 5 million scooters in just six months, and they were everywhere. On long-shadowed schoolyard evenings, all the cool kids would take turns on the scooters, testing out tricks and making skid marks on the pavement. Land a hella tight ollie, and you were a playground hero.

Here's a statistic to pop that nostalgia bubble: Razor scooters and other "ride-on" toys sent 110,000 kids to the hospital in 2001, according to a new report in the journal Clinical Pediatrics. In 1999, that number was 25,000—a jump as extreme as any trick you could land on a Razor.

According to the paper—a comprehensive crunch of 20 years of hospital data—149,000 kids go to the hospital every year for toy-related injuries. "On average in 2011," the paper states, "a child received treatment in a U.S. ED [Emergency Department] for a toy-related injury every three minutes."

By far, the most dangerous toy category in the analysis were ride-on toys like scooters, wagons, and electric-powered mini-cars (e.g., one of these bad boys you always coveted).

Number of Injuries Sustained by Children Ages 0-17, by Type of Toy (1999-2011)

Data: Clinical Pediatrics, Chart: National Journal

The most-common injuries from toys: falls (45.5 percent), collisions (22.2 percent), and foreign-body involvement (think ingestion, 10.9 percent). The risk of toy injury peaks at 2 years old, a fact that will shock no one. Boys are twice as likely to go to the hospital with toy injuries. Thankfully for boys, this gap decreases with age, disappearing around age 17. But who is playing with toys at age 17 anyway?

Number of Toy-Related Injuries by Age Group and Gender (1999-2011)

Data: Clinical Pediatrics, Chart: National Journal

But it's more than just the ride-on toys that are potentially dangerous. Every year, James Swartz and his group W.A.T.C.H.—World Against Toys Causing Harm—release a list of the top 10 most dangerous toys on the market. Swartz's late father, Ed, founded the organization in the '70s to raise awareness of the issues. As his father became more involved in advocacy, toys started disappearing from James's toy box as he grew up. "A lot of sweaters as gifts growing up," he says.

The list isn't meant to single out manufacturers, Swartz says, but rather to give parents a general sense of what types of products to avoid. The big picture: "Don't assume toys are necessarily safe because they are appearing on toy shelves," Swartz says.

The Consumer Product Safety Commission is the government agency in charge of overseeing toy hazards. "There are some consumer product categories where we are reactive, but when it comes to toys, it's the opposite—we're proactive,"  Scott Wolfson, communication director for the CPSC, writes in an email. "We do warehouse and retail inspections; we established the strongest and most comprehensive federal toy safety standard in the world." Still, some problem toys (that aren't necessarily out of compliance with the regulations, but are still dangerous) make it through.

One ride-on toy has made the list this year—the Radio Flyer Ziggle. It's a four-wheeled, foot-powered cycle that warns, "never use near motor vehicles, streets, swimming pools, hills, steps, or sloped driveways."

"When you see that many warnings, it raises the question—how can this product be used safely?" Swartz says. Any wheeled toy with a low profile presents such hazards.

Also making the list this year are some obvious ones: a bow-and-arrow kit, a "pencil turned catapult," a toy machine gun, a hammer for killing Orcs, and the enticingly named "bottle-rocket party."

But there are some nonobvious toys on the list: a baby doll with an all-too-easily removed bow, a plush toy with long, unsecured hair. There's also an alphabet pull toy meant for toddlers on the list. The problem with the toy? It has a 20-inch-long rope. According to regulations, any toy intended for a crib cannot have a rope more than 12 inches long. Because the toy is labeled as a "pull toy" and not a "crib toy," it skirts the regulation. Swartz warns that it is loopholes like these that create dangers that aren't obvious to parents, let alone their kids. (See the full list here.) Any item you give a kid could mean trouble, but parents should be aware that some categories of toys pose higher risks than others.

"There are hazards associated with a lot of items, no doubt about it," Swartz says. "Parents have to be armed with the knowledge that they can make informed choices for their children."