Seventh Generation aims to replace every potentially harmful nap mat in Vermont preschools and childcare centers in the next five years. Chemicals in flame retardants used in mats have been linked to cancer, obesity, early puberty and nervous system harm, according to Toxic-Free Future, a Seattle nonprofit. Children are exposed when the chemicals break down, escape through seams and tears, contaminate dust and air, and are ingested or inhaled. The nap mat exchange program, run by the Seventh Generation Foundation, replaced almost 850 mats at 113 Vermont centers last year and aims to replace 3,000 more this year. A 2018 study conducted by Toxic-Free Future and Indiana University's O'Neill School of Public and Environmental Affairs showed that removing foam nap mats containing chemical flame retardants can lower the level of chemicals in dust by as much as 90 percent. Seventh Generation is supplying Made Safe-certified mats from Naturepedic. Made from organic cotton, they contain no polyvinyl chloride, polyurethane foam, phthalates or added chemicals. Vermont has nearly 15,000 childcare slots for children ages 2 to 5, so Seventh Generation plans to donate 15,000 mats by the time the program ends, says Kay Gebhardt, senior sustainability scientist at Seventh Generation. "We literally want to make sure that every child in the state of Vermont who is in child care is able to go to sleep on a nontoxic nap mat."