The is urging people to stop putting on their steering wheels. The U.S. agency aftermarket emblems with rhinestones on them can turn into projectiles in the event of a crash as steering wheel airbags deploy, leading to risk of serious injury or death.

At least one driver in the U.S. so far has lost the use of an eye as a result of these rhinestones flying at their face when the airbag went off. NHTSA didn’t specify when or where the accident happened, but it may have prompted the latest warning from the agency, which asks drivers to stop steering wheels. Per :

The National Highway Traffic Safety Administration warns consumers about aftermarket steering wheel decals that could potentially cause significant injury or death. At least one driver suffered a serious injury that resulted in the loss of sight in one eye, when an aftermarket emblem adorned with rhinestones became dislodged from the steering wheel in a crash and hit the driver in the face.

The product is a metal or plastic plate, usually covered with rhinestones or other shiny decorations, with an adhesive back that covers the vehicle’s logo in the center of the steering wheel. In a crash, the force of a deploying air bag can turn the product into a projectile, resulting in serious injury or death.

Unlike the permanently affixed logo on your vehicle’s steering wheel, these aftermarket decals can easily become dislodged when the air bag is deployed. Any alterations or changes to your air bag or its cover can also cause it to not function correctly.

A report compared the decorative stones to shrapnel given the force with which they’re ejected when an airbag deploys. The emblems, rhinestones and airbag assemblies inadvertently combine into a dangerous device comparable to a claymore mine.

Airbags alone have enough explosive force to harm drivers or passengers in certain cases — the trade off being that the damage from the airbag is often much less than without it. But putting anything over a device that’s rigged to explode in the case of a crash is a bad idea, especially when it’s lots of tiny rocks.

Any decoration over the steering wheel poses a threat, but carmakers design their logos to break apart and remain fixed to the wheel rather than be ejected outwards, which is what happens to aftermarket emblems. That’s not always the case, however, as Nissan saw when it recalled some vehicles for steering wheel emblems that could fly off in a crash, per .

But that prompted a whole recall earlier this year due to the high risk of injury. There’s nothing to recall in the case of aftermarket emblems and rhinestones, which is why NHTSA is just telling drivers to avoid bedazzling their steering wheels altogether.