Infants and young children under five years of age are uniquely vulnerable to certain environmental contaminants. Some of these contaminants have been found in early learning environments (ELEs), or child care and family child care settings where children spend an average of 40 hours a week. These contaminants as well as infants' and children's unique physiology, exposures, and behaviors in child care settings are the focus of this article. Current child care and family child care licensing requirements specific to environmental health-related issues are also reviewed. Data were reviewed and analyzed from the following surveys: the 2008 Child Care Licensing Survey, the First National Environmental Health Survey of Child Care Centers, and the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants. The authors' analysis suggests that current state licensing programs impose only the most basic environmental health protection requirements. No mandatory federal regulations standardize child care and family child care regulatory efforts nationally. Resources are available, however, from federal agencies and other children's environmental health organizations that may provide guidance for how to establish better environmental health protection measures in ELEs. (author abstract)