Chemical Database



  • Formula: NH3
    Elements: Hydrogen, Nitrogen
  • CAS Number: 1336-21-6
  • CAS Number: 7664-41-7
  • Caswell Number: 044
  • RTECS Number: BO0875000
  • Synonyms/Related:
    • AM-FOL
    • Ammonia
    • Ammonia (ammonium hydroxide) 28% by weight or more NH3
    • Ammonia aqueous
    • Ammonia gas
    • Ammonia Solution
    • Ammonia solution, relative density <0.880 at 15 degree C in water, with >50% ammonia [UN3318] [Nonflammable gas, Poison gas]
    • Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia
    • Ammonia solution, strong
    • Ammonia solution, with more than 50% Ammonia
    • Ammonia solutions
    • Ammonia solutions, relative density <0.880 at 15 C in water, with >35% but not >50% ammonia [UN2073] [Nonflammable gas]
    • Ammonia solutions, relative density between 0.880 and 0.957 at 15 C in water, with >10% but not >35% ammonia [UN2672] [Corrosive]
    • Ammonia water
    • Ammonia water 29%
    • Ammonia, anhydrous
    • Ammonia, anhydrous, liquefied
    • Ammonia, aqua
    • Ammonia, aqueous
    • Ammonia, aqueous solution
    • Ammonia, gas
    • Ammonia, liquid
    • Ammonia, monohydrate
    • Ammonia, solution, with more than 10% but not more than 35% Ammonia
    • Ammonium aqueous (28% or less NH3)
    • Ammonium hydroxide
    • Ammonium hydroxide ((NH4) (OH))
    • Ammonium hydroxide (28% or less ammonia)
    • Ammonium hydroxide solution
    • Anhydrous ammonia
    • Anhydrous ammonia, liquefied
    • Aqua ammonia
    • Aquammonia
    • Aqueous ammonia
    • C01358
    • Ethyltrichloro silane
    • Household ammonia
    • NH(4) OH
    • NH4OH
    • Nitro-Sil
    • Spirit of Hartshorn
    • SX 1
    • SX 1 (ammonia water)


  • Incompatiblities:
    • acids
    • halogens
    • salts of silver
    • salts of zinc
    • strong oxidizers

Health & Regulatory Guidelines

  • EPA Regulations:
    • Reportable Quantity: 100 Lbs
    • Marine Polutant: No
  • NFPA 704 Rating:
    • Health Hazardard Rating: 3
    • Fire Hazardard Rating: 1
    • Reactivity Hazardard Rating: 0
  • NIOSH Guidelines:
    • TWA: ppm
    • STEL: ppm
    • IDLH: ppm
    • Conversion: 1 PPM = mg/m3@ 25°C & 1ATM
  • OSHA Regulations:
  • Health Risks: Toxic
  • Corrosive: Yes
  • Notes: Corrosive to copper & galvanized surfaces.

49 CFR 172.101 - Hazardous Materials Table

symHazardous materials description and proper shipping namesHaz class or divID#PGLCSpec prov §172.102Pack §173Qty limitVessel
ExcepNon BulkBulkPass air/railCargo air onlyLocOther
Current as of Oct. 6, 2011
D Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia2.2UN33182.213, T50None304314, 315ForbidForbidD40, 52, 57
I Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia2.3UN33182.3, 84, N87, T50None304314, 315ForbidForbidD40, 52, 57
D Ammonia, anhydrous2.2UN10052.213, T50None304314, 315ForbidForbidD40, 52, 57
I Ammonia, anhydrous2.3UN10052.3, 84, N87, T50None304314, 315ForbidForbidD40, 52, 57
D Ammonium hydroxide, see Ammonia solutions, etcForbidForbid
Anhydrous ammonia, see Ammonia, anhydrousForbidForbid
Aqua ammonia, see Ammonia solution, etcForbidForbid

2008 Emergency Response Guidebook Information

Produced by the US DOT the ERG is designed to aid first responders in quickly identifying specific or generic hazards of materials involved in an incident and protecting themselves and the general public during the initial response phase of an incident.

UN#GuideName of MaterialISOH20 ReactTIH Gas(es)
Current as of: Oct. 2, 2011
1005125Ammonia, anhydrousYesNo 
1005125Anhydrous ammoniaYesNo 
2672154Ammonia, solution, with more than 10% but not more than 35% AmmoniaNoNo 
2672154Ammonium hydroxideNoNo 
3318125Ammonia solution, with more than 50% AmmoniaYesNo 
Isolation and Protective Action Distances Table
UN#Name of MaterialFirst ISOLATE in all DirectionsThen PROTECT Persons Downwind During-First ISOLATE in all DirectionsThen PROTECT Persons Downwind During-

Please see: How to use the table of initial isolation and protective action distances

Current as of: Oct. 2, 2011

1005Ammonia, anhydrous301000.
1005Anhydrous ammonia301000.
3318Ammonia solution, with more than 50% ammonia301000.

Related Resources

  • USDOT Hazardous Materials Table 49 CFR 172.101
    An online version of the USDOT's listing of hazardous materials from 49CFR 172.101. This table can be sorted by proper shipping name, UN/NA ID and/or by primary hazard class/division.
  • 2008 ERG (Emergency Response Guidebook)
    Have you ever wondered what those four digit numbers on the placards on the side of trucks and rail cars mean? Our online 2008 ERG will give you your answer. This is an online version of the guidebook produced by the USDOT for first responders during the initial phase of a Dangerous goods/HazMat incident. ERG data last verified/updated Oct. 2, 2011
  • US DOT Hazardous Materials Transportation Placards
    Hazardous materials placards (DOT placards) are required when shipping hazardous materials in the United States, Canada and Mexico. These pages provide US DOT definitions for each hazmat placard.
  • Guide for Handling Household Chemicals
    Things you can do to make your home safer.
  • Molarity, Molality and Normality
    Introduces stoichiometry and explains the differences between molarity, molality and normality.
  • Molar Mass Calculations and Javascript Calculator
    Molar mass calculations are explained and there is a JavaScript calculator to aid calculations.
  • Periodic Table of Elements
    Provides comprehensive data for each element of the periodic table of elements including up to 40 properties, names in 10 languages and common chemical compounds. Information also provided for 3,600 nuclides and 4,400 nuclide decay modes.

Editor's note: Some chemicals in this database contain more information than others due to the original reason this information was collected and how the compilation was accomplished.

While working with material safety data sheets (MSDS), I found that manufacturers sometimes used obscure names for constituent chemicals and I didn't always have a good idea of what I was dealing with. To resolve this problem, over the years, I compiled chemical names and identifiers into a personal database, cross referencing regulatory and health safety information when possible. Colleagues and friends eventually started suggesting that I make my data available on this website so that others could benefit from my efforts -- which I finally did in 2004. The more common, regulated and/or hazardous a chemical is, the more information I will have likely collected it.


If you are aware of any synonyms listed above that are registered trademarks, please contact us with relevant information so that trademarks can be appropriately noted.

Notes about mixtures

Some chemicals listed in this database or not pure chemical compounds, rather they are mixtures/solutions of chemicals. It is not uncommon for wide range of molar ratios of a mixture to be lumped together as "synonyms" of the same "chemical". In some instances chemicals that are very similar from a health & safety and/or regulatory standpoint also may have been lumped together.

Reference Sources

Data for this database was compiled from: hundreds of Material Safety Data Sheets (MSDS) of common industrial and household products; the Hazardous Materials Table from the United States "Code of Federal Regulations" title 49 section 172.101; the National Institute for Occupational Safety and Health Pocket Guide to Chemical Hazards; the US DOT 1996, 2000 & 2004 Emergency Response Guidebooks; U.S. National Library of Medicine and many other related resources.


WARNING: These pages are for general reference and educational purposes only and MUST NOT be relied upon as a sole source to determine regulatory compliance or where matters of life and health are concerned. This site and the author do not warrant or guarantee the accuracy or the sufficiency of the information provided and do not assume any responsibility for its use.

To ensure regulatory compliance when transporting hazardous materials or dangerous goods, one must receive proper training and certification from a qualified instructor and refer to the current year's Code of Federal Regulations Title 49 (49CFR) or your country's shipping regulations. In matters regarding workplace safety, refer to current OSHA regulations (29CFR) and NIOSH guidelines or your own country's health and safety regulations. No one should ever enter into a hazardous environment without proper training from qualified instructors.

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