– Searching for videos on how to juggle knives while balancing a chain saw? Taste battery acid? Tie a noose? How about “My Little Pony”-themed pedophilia jokes?

You can find all of this, and more, on YouTube Kids, the new smartphone application Google has marketed as safe for preschoolers, according to consumer groups who compiled a disturbing ­dossier of the app’s content.

Those groups on Tuesday asked the Federal Trade Commission to investigate Google’s app for unfair and deceptive business practices, the second such complaint filed since the kid-centric video service started in ­February.

“The deeper you get into this, the scarier it is in placing children at risk,” said Dale Kunkel, a University of Arizona communications ­professor. “I’m astonished at the volume of inappropriate material, much of which will be harmful for kids if they see it.”

Google said in a written statement Monday that it works to make the app’s videos “as family-friendly as possible” and takes feedback very seriously, removing inappropriate videos flagged by users. In an interview shortly after ­introducing YouTube Kids, its product manager, Shimrit Ben-Yair, said that the mobile app uses a “two-step process” to select kid-friendly content from the 300 hours of video uploaded to YouTube each minute.

The first step is to “algorithmically narrow it down to family-friendly content,” she said. The second involves Google employees doing a “manual sampling for quality control, to see if it’s family-friendly.”

But that filter is not working, according to advocates and some parents who wrote reviews on the Google Play and iTunes stores documenting how their children discovered violent, sexually explicit or other jaw-dropping content.

The complaint filed with the FTC is just the latest headache for Google’s attempted leap into the toddler tech market.

Kunkel was part of a coalition of prominent child advocacy and consumer groups that filed an April complaint with the FTC accusing YouTube Kids of being overly commercialized, inundating young children with ads and promotional content that would not be allowed on broadcast TV.

The FTC said at the time it would look into the complaint. Only later, however, did advocates begin to discover more troubling content. While the app is geared toward young children who cannot yet spell or type, they can easily find some of the videos by using their voice. “For parents who want a more restricted experience, we recommend that they turn off search,” Google said.