Hitachi Chemical Co. and Boehringer Ingelheim GmbH may abandon factories largely unscathed by last month's Japan earthquake and tsunami as the nuclear plant radiation crisis continues.

Boehringer, the world's largest family-owned drugmaker, halted production at a factory that makes energy drinks in Namie, Fukushima Prefecture, about 10 km from the leaking power station, following the March 11 temblor and tsunami. Hitachi Chemical shuttered a plant making carbon brushes for train motors in the same town, causing a parts shortage that disrupted rail services.

"We have no idea when we will be able to go back," said Masayuki Hasegawa, a spokesman for the Tokyo-based Hitachi Ltd. unit. The company hasn't decided on the long-term future for the plant, which employed 200 people and had annual sales of about ¥5 billion, he said.