ANSI K61.1:1999 Safety Requirements for the Storage and Handling of Anhydrous Ammonia.
Ammonia is extremely hard to ignite and is a relatively stable compound. It begins to dissociate into nitrogen and hydrogen at approximately 850 °F (454 CC) at atmospheric pressure. Experiments conducted by a nationally recognized laboratory showed that an ammonia-air mixture in a standard quartz test container does not ignite at less than 1562 °F (850 CC). Ammonia gas is flammable in the air in the range of 16% to 25% by volume. Conditions favorable for ignition are seldom encountered during normal operations due to the high ignition temperature required. However, the release of ammonia gas into a tightly enclosed or inadequately ventilated space may result in the accumulation of a flammable mixture that can cause a combustion explosion if a high temperature ignition source is present.
1.3.5
Under some circumstances ammonia and ammonium compounds can react with other chemicals to form explosive products. Ammonia should never be combined with other chemicals unless the possible reactions have been adequately investigated and appropriate precautions taken. Refer to NFPA 45. Hazardous Chemicals Data (5].
1.3.6
Although most metals are not attacked by ammonia, zinc, copper, and copper base alloys such as brass are subject to rapid deterioration by ammonia. Certain high tensile strength steels have developed stress-corrosion cracking in ammonia contaminated with small quantities of air. Such cracking can be minimized by the consistent use of 0.2% water by weight in the ammonia as an inhibitor. Weld heat affected zones can be areas of high hardness, which are susceptible to stress corrosion cracking. U.S. Department of Transportation (DOT) regulations require that ammonia cargo tanks constructed of such steels be post-weld heat treated.

2.25 Positive pressure Self-contained Breathing Apparatus (SCBA)
A full facepiece respirator approved by NIOSH/MSHA for respiratory protection for both entry into, or escape
from. oxygendeficient atmospheres or a concentration of gases or vapors that are immediately dangerous to
life or health where the supply of air is carried by the wearer. The air pressure inside the facepiece is positive in
relation to the air pressure of the outside atmosphere during exhalation and inhalation.
2.26 Pressure relief valve
A device designed to open to prevent an increase in internal fluid pressure in excess of a specified value due
to an emergency or abnormal condition and to close and prevent further flow after normal conditions have been
restored.
2.27 ProtectIve gloves, boots, and suits
Items made of rubber or other material impervious to ammonia. Gloves refer to gauntlet-style of sufficient length to allow for cuffing, and which provide thermal protection suitable for ammonia exposure.
2.28 Pounds per square inch gauge (psig) and pounds per square inch absolute (psia)