St. Louis ? A consumer group contends one of the holiday season’s must-have toys is unsafe.

But the maker of the robotic Zhu Zhu Pets hamsters defended its product Saturday against a study by San Francisco-based GoodGuide that said higher-than-allowed levels of the chemical antimony were found in the toy.

Good Guide named Zhu Zhu Pets hamsters one of the top-selling toys with low ratings after finding antimony, which can cause health problems, on the hair and nose of one of the toy hamsters, called Mr. Squiggles.

The group assigned the toy, aimed at 3- to 10-year-olds, a rating of 5.2 on a 10-point scale.

But the toy’s maker, St. Louis-based Cepia LLC, insisted in a statement that its product is safe and has passed rigorous testing. The company said it was contacting GoodGuide to share its testing data and determine how the report was founded.