Illegal or Dangerous Items
If you think you can put everything that crosses your mind in a safe deposit box, you’ve got another thing coming.
Your bank should have a list of items allowed to be kept in a safe deposit box. It goes without saying that anything illegal, such as illicit drugs, or dangerous, like firearms, explosives and hazardous materials, is not allowed.
However, different banks may have different rules, therefore, you should always read the fine print provided by your bank. If things are still not clear, you can always ask your banker to clarify any hazy aspects.