CIDEX OPA Treatment

CIDEX® OPA is used commonly in hospitals and some research laboratories to disinfect medical and some research devices.

OPA (orthophthaldehyde) is very toxic to fish. Therefore, waste CIDEX® OPA needs to be treated before it can be poured down the drain. The OPA concentration in waste CIDEX® OPA is usually about 0.3-0.5%, but the King County sewer discharge limit is 0.01%.

Many commercial products are available to treat CIDEX® OPA. Follow product instructions for treatment time.

Please let us know if you begin to treat CIDEX® OPA by calling us at 206.616.5835 or emailing us at By law we are required to keep track of all hazardous waste treatment on campus. Please track the waste you treat using the Chemical Treatment Log.