Children’s accidental exposure to the opioid addiction medication buprenorphine is increasing, according to new data from U.S. poison control centers.

Between 2007 and 2016, poison control centers received 11,275 calls about children’s exposure to buprenorphine, CNN reports. Eighty-six percent of exposures were in children younger than 6, and 89 percent of the exposures were unintentional. Buprenorphine can dangerously slow young children’s breathing. Almost one-quarter of the children under 6 who are exposed spend time in intensive care, the researchers noted.

Teens accounted for 11 percent of buprenorphine exposures. The researchers report in Pediatrics that 77 percent of teen exposures were intentional, including 12 percent suspected suicides. More than 25 percent of teens used buprenorphine with at least one other substance.

The researchers said they expect the number of children and teens who are exposed to buprenorphine to continue to rise.