China's exports of germanium and gallium products in August plunged to zero,customs data showed on Wednesday, due to new export controls on the two chipmaking metals.

Beijing exported no wrought germanium products last month, compared to 8.63 metric tons in July when volumes more than doubled from June as overseas buyers rushed to lock in supply ahead of the curbs.

There were also no exports of wrought gallium products in August. In July, exports were 5.15 tons and 7.67 tons in the same month in 2022, the data showed.

In July, China announced restrictions on the export of eight gallium and six germanium products starting Aug. 1, the latest salvo in an escalating war between Beijing and Washington over access to materials used in making high-tech microchips.

Under the new rules, exporters of germanium and gallium products now need to obtain an export licence for dual-use items and technologies, meaning those with potential military and civilian applications.

Permit applications take around 45 working days to process, said a Chinese germanium trader and a germanium producer, who declined to be named because of the sensitivity of the matter.

"We did not ship any volumes abroad last month as we are still waiting for a permit," the trader added. Chinese spot gallium prices slid last month as stocks piled up in the domestic market due to the export controls and subdued demand.

The spot price of gallium metal fell by 9% on the month to 1,655 yuan per kg on Aug. 31, according to data from Shanghai Metals Market (SMM).

The spot price of germanium ingot , however, climbed by 1% during the month to 9,700 yuan per kg at the end of August, SMM data showed, helped by tightening supply.

China's exports of wrought germanium totaled 36.45 metric tons in the first eight months of 2023, up 58% on the year while shipments of wrought gallium fell 58% on the year to 22.72 tons over the January-August period. (Reporting by Amy Lv and Dominique Patton in Beijing; Editing by Christian Schmollinger and Miral Fahmy)