Maryland officials say the state will again spray pesticide Permanone 30-30 to control mosquito populations, after EPA testing determined it does not contain dangerous PFAS.

The Baltimore Sun reports that the Maryland Department of Agriculture temporarily halted use of the pesticide in the state this year “out of an abundance of caution,” after testing by an outside lab found 3,500 parts per trillion of one type of PFAS, and 630 parts per trillion of another.

But testing by EPA scientists at Fort Meade returned a different result. PFAS, are also known as “forever chemicals.” That’s because they can linger in the human body for long periods of time.