IRIS Assessment for Ammonia

EPA, 20 September 2016

The first thing that probably comes to your mind when I say ‘ammonia’ is that household product you use to clean just about anything in your house.

Besides being used as an all-purpose cleaner, ammonia also occurs naturally in air, soil, and water.  As you’re reading this, you’re producing ammonia too – it’s used in nucleic acid and protein synthesis, and helps your body maintain its acid-base balance – all part of normal biological processes.

The largest and most significant use of ammonia is in agricultural fertilizers, which represents about 80% of commercially produced ammonia.

Ammonia is also used in food products as an antimicrobial agent, in water purification, and in refrigeration systems.  It’s also an important chemical intermediate in the production of pharmaceuticals and other chemicals, and is used to reduce nitrogen oxide emissions from combustion sources like some industrial boilers and diesel engines.

Some major sources of ammonia gas come from leaks and spills during the production, storage, or processing stages of the chemical.  Other sources include decaying manure from livestock, application of fertilizers in agricultural, and sewage or wastewater emissions in the environment.

EPA’s Toxic Release Inventory reports that over 150 million pounds of ammonia was released from reporting facilities in 2014.  There are a number of ways that humans can be exposed to ammonia.  The most common route of exposure is through breathing air that contains ammonia.  Humans can be exposed to ammonia gas from household cleaning products or through direct skin contact via products that contain the chemical.

Livestock and poultry farmers that work in animal feeding operations or confinement areas can be exposed to ammonia released from animal waste, and farmers can be exposed when applying ammonia-containing fertilizers to fields.

To characterize the potential health effects that humans can acquire from inhaling high concentrations of ammonia, EPA recently released an Integrated Risk Information System (IRIS) assessment that looks at the non-cancer health hazards that may result from inhalation of ammonia.