SAN DIEGO -- When Gigi went on a shopping errand with her mom Laurie Zinkel last October, the last thing the five-year-old expected was to get hurt.

"He just pushed me into the hook," said Gigi Zinkel. "It went through my lip to my gum."

"After that she started screaming," said Laurie Zinkel. "I had seen it happen, but it happened so quick that your gut reaction is just to grab her."

A display hook is what injured Gigi. It's used to hang products for sale like stickers, clothes and toys. This particular hook –- a single wire with a straight-cut end -- is considered one of the most dangerous ones.

"An unsafe hook or an unsafe display is when the exposed end can injure you and the display doesn't in some way protect you from contact with that hook," said building safety expert Larry Dinoff.

Dinoff investigates building safety, including retail displays, and has written about display hook injuries.

"The most common injury and the one that's been spoken about in the safety literature for years is an eye impalement," said Dinoff.

Children and adults have been cut or impaled by unsafe display hooks. A two-year-old in Ohio fell on a display hook in 2002 and it punctured her brain. Dinoff says children are especially at risk of being hurt.

"They don't have an adult's ability to see a hook as dangerous. The displays that are usually hung on these hooks, especially if they're aimed at children, are very colorful and attractive."

Though there is no comprehensive data base of these types of injuries, the anecdotal evidence is children are the most vulnerable.

"Children's balance is different than an adult's balance so they're more likely to fall. And with sharp hooks sticking around they're falling onto a pin cushion."

Another example of a dangerous display hook is a wire with a small rounded end. It may not cut someone, but it doesn't protect you from impalement.

"They have the ability to penetrate quite well," said Dinoff.

The 10News I-Team went undercover into large chain stores around San Diego County and found unsafe display hooks in wide use. They found that many stores use a variety of hooks, sometimes with unsafe ones right next to safe ones.

Hooks that have a large curved end are safe. So are the ones with two prongs and a plastic rectangle mounted on the end that guards you from the exposed wires.

Dinoff says stores have known about this hazard for years and that the solution is an easy one.

"The only thing required to prevent this is to use readily available safe products instead of less expensive unsafe products," he said.

What exactly is the price of safety? To buy one thousand display hooks, the dangerous versions cost about 12 cents a piece. The safer loop hooks are also about 12 cents each. And the safe hooks which include a price tag holder start at about 29 cents each.

The 10News I-Team contacted the retailers where they found the dangerous hooks. Click here to read their responses. The I-Team also shared its findings with California legislators and will keep you informed of any developments.