Radioactive Material  From  Fertilizer Production
An ingredient in some fertilizers is the mineral phosphorous. The most common method for making fertilizer
containing phosphorous leaves behind a waste called phosphogypsum.

      Phosphogypsum emits radon, a radioactive gas. It also contains uranium and radium, which are
       radioactive elements.

      Phosphogypsum is stored in big piles called stacks. Some stacks cover hundreds of acres and are
       hundreds of feet high.

      As the phosphogypsum dries out, it forms a thick crust that keeps the radon from escaping into the air.

About Radioactive  Material  From Fertilizer Production

Phosphate rock contains the mineral phosphorus, an ingredient
used in some fertilizers to help plants grow strong roots.
Phosphate rock also contains small amounts of naturally
occurring radionuclides, mostly uranium and radium. When
processing phosphate rock to make fertilizer, the phosphorous is
removed by dissolving the rock in an acidic solution. The waste
that is left behind is called phosphogypsum. Most of the naturally
occurring uranium and radium  found in phosphate rock end up in
this waste. As a result, phosphogypsum has a higher
concentration of these naturally occurring radioactive elements.
Uranium decays to radium and radium decays to radon, a
radioactive gas.
The waste that is produced in fertilizer production is stored in
large piles (stacks). In the aerial photo at right, you can see that
the top of a phosphogypsum stack is covered in water.
Phosphogypsum is very watery when it is first put on the stack.
As the phosphogypsum dries out, a crust forms on the stack.
The crust thickens over time,  reducing the amount of radon that
can escape and  helping keep the waste from blowing in the

Rules and Guidance


EPA has regulated phosphogypsum since 1989. It has banned
all use of this waste unless it has very little radioactivity. EPA
requires phosphogypsum to be placed in stacks.
Phosphogypsum is watery at first. As it dries,
  it forms a crust, which blocks most of the
                                                            Phosphogypsum waste is stored in stacks.
  United States Environmental Protection Agency | Office of Radiation and Indoor Air (6608T)  | EPA 402-F-14-004 | August 2014 | p. 1

Some states have worked with EPA to write rules for managing phosphogypsum. In Florida, companies have
to follow special rules to close (shut down) a stack that won't be used any more. Florida is also working on
ways to reduce the amount of waste from the wet acid process that creates phosphogypsum.

What you can do

Phosphogypsum stacks are located on private property away from people. Unless you are visiting a facility,
you will not encounter a phosphogypsum stack.

Where to learn  more

You can learn more about radioactive material from fertilizer production by visiting the resources available on
the following webpage:
  United States Environmental Protection Agency | Office of Radiation and Indoor Air (6608T) | EPA 402-F-14-004 | August 2014 |  p. 2