Ammonia (NH3)

NH3, Ammoniak

 At room temperature, ammonia is a colourless gas with a strong, pungent odour¹. Ammonium ions (NH₄⁺) and hydroxide ions (OH^-) are formed when ammonia reacts with water.

Uses

Ammonia is used within industry for production of artificial fertilizers, nitric acid, amines, paints, fibres, plastics, nylon and explosives. Ammonia is also used in flue gas treatment for reduction of nitrogen oxides and as cooling agent in refrigeration². Ammonia is available to the general public through products such as artificial fertilizers and alkali cleaning products (e.g. window cleaners and floor cleaners).

Sources and transportation pathways

Ammonia is both produced synthetically and formed naturally by degradation of organic matter containing nitrogen. Handling of fertilizer within agriculture is the single largest source of ammonia emissions in Sweden³. Ammonia is emitted to air, where it is converted into ammonium (NH₄⁺) and is deposited to land, water and vegetation⁴. The chemical reaction of ammonia to ammonium may occur before or after deposition⁵.

Effects on environment and health

Deposition of ammonia results in acidification and eutrophication of land and water⁶. Acidification harms plants and animals, both on land and in water⁷. When the ground turns acidic, vital nutrients are leached from the soil, which eventually may result in reduced forest growth. Furthermore, metals are released in the ground that can harm decomposing organisms in the ground as well as birds and mammals higher up in the food chain, including humans⁸. Eutrophication occurs when there is an excess of nutrients (e.g. nitrogen) in land or water⁹. The abundance of nutrients threatens biological diversity by allowing species that thrive in a nutrient-rich environment to outcompete species that are adapted to a more nutrient-poor environment¹⁰.

In concentrated solution, ammonia is strongly corrosive. Ammonia gas causes severe irritation of eyes and mucous membranes. Inhaling highly concentrated ammonia gas may cause difficulty in breathing and lung damage¹¹.

International agreements and regulations

Ammonia is regulated by the UN Convention on Long-range Transboundary Air Pollution (CLRTAP) as well as by the EU National Emissions Ceilings Directive (2001/81/EC) and the EU Industrial Emissions Directive (2010/75/EU). The UN Protocol on PRTRs and the EU E-PRTR regulation regulate how data on ammonia emissions is made available.



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¹ http://prtr.ec.europa.eu/#/pollutantinfo
² http://www.yara.se/industriella-losningar/process-kemikalier/ammoniak/ 
³ http://www.naturvardsverket.se/Sa-mar-miljon/Statistik-A-O/Ammoniak-utslapp-till-luft/
⁴ https://www.eea.europa.eu/publications/air-quality-in-europe-2016
⁵ https://www.naturvardsverket.se/Documents/publikationer/91-620-8089-X.pdf?pid=3879
⁶ http://www.naturvardsverket.se/Sa-mar-miljon/Klimat-och-luft/Luftfororeningar/Kvaveoxider/
⁷ https://www.eea.europa.eu/publications/air-quality-in-europe-2016
⁸ http://www.airclim.se/f%C3%B6rsurningens-effekter
⁹ https://www.eea.europa.eu/publications/air-quality-in-europe-2016
¹⁰ http://www.miljomal.se/sv/Miljomalen/7-Ingen-overgodning/
¹¹ https://giftinformation.se/kemikalieregister/ammoniak/