The world’s supply of memory chips could be in danger due to new export rules Japan has placed on South Korea. Beginning this week, Japanese suppliers can no longer export three chemicals integral to semiconductor manufacture without prior government approval.

This process happens to take three months, so delays are expected. SK Hynix admitted it didn’t have 90 days of inventory and might have to halt production until it can get its hands on the necessary chemicals. Chip leader Samsung hasn’t commented yet, but its situation could be the same as SK Hynix’s.

Lesser-known Japanese companies hold leading market shares in the three restricted materials. Polyimides are used to make flexible organic light-emitting diode displays. The others are used in forming circuit patterns: resist — a coating substance — and etching gas. These companies include JSR, Showa Denko and Shin-Etsu Chemical — all of which are a third or more owned by foreign investors.

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