Ammonia (NH3)
Ammonia Detector (NH3) - Personal Gas Monitor & Alarms
Ammonia gas is a severe respiratory tract irritant. It is noticeable by smell at 0.6 to 53 ppm. Volunteers have first noticed nose and throat irritation at concentrations as low as 24 ppm after 2-6 hours exposure. A 10-minute exposure to 30 ppm was considered faintly irritating by 2/6 volunteers, while 50 ppm was considered moderately irritating by 4/6. Irritation of the nose and throat was noticeable in 5/10 and 10/10 volunteers after a 5-minute exposure to 72 or 134 ppm. At 500 ppm, immediate and severe irritation of nose, and throat occurs. Brief exposure to concentrations above 1500 ppm can cause pulmonary edema, a potentially fatal accumulation of fluid in the lungs. The symptoms of pulmonary edema (tightness in the chest and difficulty breathing) may not develop for 1-24 hours after an exposure. Numerous cases of fatal ammonia exposure have been reported, but actual exposure levels have not been well documented. If the victim survives, complete recovery may occur depending on the extent of injury to the respiratory tract and lungs. However, long-term respiratory system and lung disorders have been observed following severe short-term exposures to ammonia.
People repeatedly exposed to ammonia may develop a tolerance (or acclimatization) to the irritating effects after a few weeks. Tolerance means that higher levels of exposure are required to produce effects earlier seen at lower concentrations.