Iridium-192 is nasty stuff—the isotope is so radioactive that if it comes into contact with the skin the only remedy is often amputation. It can cause harm, or even death, from up to 30 meters away. Yet when a company in the Chinese city of Nanjing misplaced a soybean-sized piece of the stuff on May 7, it neglected to tell the public for 36 hours.

The radioactive pellet eventually turned up in a grassy area a kilometer from its original location, a construction project owned by state-run oil company Sinopec. The Tianjin Hongdi Engineering Development Company was using the isotope to check for flaws in metal components. The iridium was eventually found on May 9 in a plastic bag, indicating that it had been handled by someone, perhaps looking for scrap materials to salvage.

People “should not pick up metals,” Tang Shuangling, director of the radiation prevention and environmental protection department under Nanjing University of Science and Technology, helpfully suggested in an interview with the state-owned China Daily.

The loss or theft of dangerous radioactive isotopes happens distressingly often. Thieves stole a container full of cobalt-60 in Mexico last year, likely burning or killing themselves in the process, and a container of iridium-192 was lost en route to Kathmandu, Nepal on May 1.