After the deadly Oklahoma City bombing and the most recent explosion in Oslo, Norway, the Department of Homeland Security has proposed regulating the sale and transfer of 25 pounds or more of ammoniun nitrate.

Although it is one of the most widely used fertilizers in agriculture, ammonium nitrate also is an ingredient in home-made bombs.

The Ammonium Nitrate Security Program, as proposed, would require those selling ammonium nitrate to retain records and report thefts or losses of the product within 24 hours of discovery, according to a news release.

Homeland Security would issue registration numbers to those approved to buy, sell or transfer ammonium nitrate.

Read the full proposal in the Federal Register.

Homeland Security will accept public comments for 120 days.