As Halloween approaches, excitement builds over costumes, decorations, and festivities but a recent study raises alarming concerns about the safety of popular Halloween costumes.

The Center for Environmental Health (CEH) says it has found harmful substances in costumes from major retailers.

The CEH says it found hazardous materials such as lead, cadmium and BPA in costumes sold at Halloween Express and Spirit Halloween.

According to Mihir Vohra, CEH's science lead, these substances were present at levels that exceeded California's safety standards.

"These findings are troubling," Vohra said.

Lead exposure poses significant risks, especially for children. Even low levels can lead to nervous system damage and cognitive impairments.

Cadmium, another dangerous substance, can cause severe health issues, including gastrointestinal damage.

BPA, an endocrine disruptor, is linked to numerous health problems, including fertility issues and certain cancers.

Federal regulations regarding hazardous chemicals in clothing are limited. The U.S. government has banned only three substances—lead, cadmium, and some phthalates—from children's clothing.

Proposition 65, California's law requires labeling for hazardous chemicals. The group says consumers should pay close attention to warnings associated with costumes.

A study by researchers from Ikea and H&M tested secondhand polyester clothing and discovered another harmful phthalate, DEHP, in nearly half of the samples. Miriam Diamond, a professor at the University of Toronto, noted that elevated phthalate levels were found in children's costumes tested during a separate investigation.

Additionally, wearing plastic-based costumes can exacerbate health risks. Heat can cause sweat to leach hazardous chemicals from synthetic fabrics, leading to prolonged exposure.

"The chemicals can degrade over time, contaminating other clothing when stored together," Diamond says.