Two 25-gram bottles, one each of potassium cyanide and sodium cyanide, have gone missing from a laboratory at Osaka Metropolitan University’s Graduate School of Engineering.

A laboratory worker discovered that the bottles of highly toxic compounds were missing during an inventory check of poisons at around 1 p.m. on May 2. The matter was only reported to the university's management on Tuesday.

The compounds are fast-acting poisons — a dose of between 200 and 300 milligrams of either is considered lethal for an adult. If completely full, each bottle would contain enough of the chemicals to cause the deaths of at least 80 people. The university is not sure how much of the compounds remain in the missing bottles.

The university's vice president, Hiroyuki Sakuragi, apologized during a Thursday news conference in Osaka, bowing deeply and admitting that there had been a “significant delay” in notifying the police and other agencies.

“We deeply apologize for causing concern to all stakeholders related to the university, the neighboring community and the public,” Sakuragi said.

Two faculty members and several students searched the laboratory from May 7 to 10 but did not find the missing chemicals, Sakuragi said. A report was then made to the university's management on Tuesday afternoon.

The bottles had been stored in a locked cabinet with its electronically managed key accessible only to registered users, Sakuragi said.

The university has reviewed its records and interviewed faculty members and students but has been unable to determine the whereabouts of the missing bottles.

Its records show that they have not been used since 2010. The last time they were seen in the cabinet was in June 2023.

Having conducted a survey at all its laboratories, the university confirmed that no other chemicals were missing as of Thursday morning. It has consulted with the Sumiyoshi Police Station in Osaka Prefecture about the matter and plans to file a formal report on Friday morning.

Koichi Kitayoshi, a spokesperson for the Sumiyoshi Police Station, said Thursday evening that the police are not able to comment on the details of the case yet, but will handle it accordingly once they receive the university’s report.