Buyers have canceled several Libyan Amna, Abu Attifel and Zueitina crude oil purchases after high mercury levels were detected in the cargoes, sources close to the matter said Jan. 21.

According to S&P Global Platts, the sources said that the issue had so far only impacted the three grades of Amna, Abu Attifel and Zueitina.

State-owned National Oil Corporation has reoffered some of the January-loading cargoes through an official tender, the sources added.

“Some Amna crude cargos, which load from Ras Lanuf are now being tested in Tripoli to make sure there is no mercury contamination,” one source close to the matter said.

Representatives at NOC were not immediately available for comment on the matter, despite several attempts.

One source said that the aging oil infrastructure in Libya could have caused the rise in mercury levels. Mercury from crude oil can also accumulate in processing equipment and in oil storage tanks, when it is not maintained well.