Materials maker Ube Industries on Friday disclosed that its plant in Ichihara, Chiba Prefecture, had skipped quality-control checks for some of its low-density polyethylene products since the 1990s.
The products in question, used to insulate power and telecommunications cables, were sold by Ube-Maruzen Polyethylene Co., a joint venture with Maruzen Petrochemical Co., to 50 clients including wire makers.
At the plant, some of the checks requested in clients’ delivery specification sheets weren’t conducted, although bogus inspection reports were drawn up to make it look like they were, the company said.
This has been going on since the 1990s, Ube Industries Ltd. President Yuzuru Yamamoto told a news conference.
Ube Industries said it has set up a panel of lawyers and outside directors to investigate the matter.
After detecting the problem on Dec. 11 last year, the company says it conducted checkups to make sure there were no problems in product quality before briefing the clients, which is why it took two months to announce the revelation.
Full quality checks began on Dec. 20, it said.
“We deeply apologize for causing great inconvenience to those concerned,” Yamamoto said.
Yamamoto denied he would resign over the matter, adding that it is his responsibility to take measures to prevent the problem from recurring.