Twenty patients at the Veterans Affairs Pacific Islands Health Care system were potentially exposed to blood-borne pathogens in May after dental instruments that were “clean” but had not completed the sterilization process were used, the VA said on Friday.

“Although the risk is determined to be extremely low, (VA) staff will contact those patients to disclose this incident,” the VA said in a notification to congressional members.

For exposed patients who desire testing, blood tests for Hepatitis B, Hepatitis C, and HIV will be administered with a scheduled follow-up at 13 weeks and six months, the VA said.

“VA sincerely apologizes to veterans who may have been affected,” the federal agency said.

The VA Pacific Islands Health Care System patients were exposed to the unsterilized dental equipment on May 23 and 27, the VA said.

“Per standard procedure, the instruments had been sent to the Tripler Army Medical Center Central Materiel Service for sterilization processing, and when they were returned to the facility, Dental Department staff failed to notice wrapping indicated the instruments had been cleaned but not completely sterilized,” the VA said.

“Review of the patient log indicated that the instruments potentially were used in minimally invasive, routine dental procedures on twenty patients before being discovered on May 27.”