Uranium sinker bars.

CFR · 2024-01-01 · US · Title 10

The licensee may use a uranium sinker bar in well logging applications only if it is legibly impressed with the words “CAUTION—RADIOACTIVE-DEPLETED URANIUM” and “NOTIFY CIVIL AUTHORITIES (or COMPANY NAME) IF FOUND.”

official document · source cfr-2024 · id 10:§ 39.49