AP

You might want to think twice if you are making your kids a peanut butter sandwich for lunch.

The sandwich could contain flame retardant.

Researchers sampled 36 foods commonly purchased in supermarkets, including peanut butter, turkey, fish and other fatty foods between 2009 and 2010. The scientists say nearly half of their samples had detectable levels of HBCD, the commercial flame retardant mixture used in foam insulation.

The study's author is from the University of Texas School of Public Health in Dallas. It's published in the academic journal Environmental Health Perspectives, published by the U.S. National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services.

Researchers purchased the samples from Dallas-area supermarkets between 2009 and 2010. The foods with detectable levels tended to be items with fish like canned sardines or fresh salmon or products with meat like deli-sliced turkey or ham in them. One out of the three varieties of chili with beans also tested positive.

HBCD has not been found to have any adverse effect on humans, though some experts warn that damaging effects could be discovered in the future. In animals, HBCD has been found to disrupt hormones in the endocrine system and in the thyroid.

Specific brands tested were not named in the study.