Are Freon methods for Total Petroleum Hydrocarbons (TPH) also withdrawn?
Because TPH is not part of CWA monitoring there is no TPH method at Part 136 to withdraw. However, some entities require use of an EPA-published method for TPH determinations that uses a Freon solvent. We note that recent air regulations specifically disallow use of methods, such as the Freon-based TPH methods. You might consult with appropriate parties before continuing to use Freon-based analytical methods.
