PORTLAND, Ore. (AP) – Inmates at Oregon’s only prison for women are accusing staff of mixing up breast milk they pumped for their infants on the outside, potentially exposing their children to risks.

The Oregonian reports that four inmates at Coffee Creek Correctional Facility in Wilsonville say prison staff mixed up their bags of milk last fall. One of the nursing mothers was diagnosed with Hepatitis C, causing the mothers to worry about their children’s health.

Oregon Department of Corrections spokeswoman Betty Bernt says milk program supervisors have addressed the problem and now require inmates to check bags before they are sent to caregivers.

Inmates were notified in December that Hepatitis B and C are unlikely to be transmitted through breast milk.