SEOUL (Reuters) – Samsung Electronics’ semiconductor production in China is facing disruption from South Korean truckers blocking exports of a key chip-making material as part of a strike, the Korea International Trade Association (KITA) said on Tuesday.

In the first concrete sign that the week-long strike has begun impacting chip production, KITA said a Korean company that produces isopropyl alcohol (IPA), a raw material for cleaning chip wafers, is facing complications in shipping the product to a Chinese company that in turn supplies wafers to a Samsung Electronics chip factory in China.

KITA said in a statement that a week’s worth of shipments of have been delayed.

Samsung Electronics did not immediately comment. It produces NAND flash chips at its plant in Xian, China.

(Reporting by Byungwook Kim and Joyce Lee; Editing By Tom Hogue and Kenneth Maxwell)