Substance profile
Ammonium hydroxide
Ammonium hydroxide is a colorless liquid with an intense, pungent, suffocating odor.
01 · Identification
What Ammonium hydroxide is
Ammonium hydroxide is a colorless liquid with an intense, pungent, suffocating odor. It boils at 38 °C, melts at -58 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
02 · Identifiers
Ammonium hydroxide identifiers and molecular data
Ammonium hydroxide CAS number and EC number
Ammonium hydroxide molecular formula and molecular weight
Other names for Ammonium hydroxide
- ammonia solution
- aqueous ammonia
- ammonia water
- NH4OH
- Ammonia, Aqua
- Ammonia, Monohydrate
- Aqua Ammonia
- ammonia ....%
03 · GHS classification
Ammonium hydroxide hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Ammonium hydroxide pictograms and signal word
Ammonium hydroxide hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Skin corrosion/irritation GHS chapter 3.2 | Category 1A or 1B or 1C | H314 | GHS05 |
| Hazardous to the aquatic environment - acute GHS chapter 4.1 | Category 1 | H400 | GHS09 |
Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.
Ammonium hydroxide hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H314 | Causes severe skin burns and eye damage. |
| H400 | Very toxic to aquatic life. |
This page lists only the codes assigned to Ammonium hydroxide. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Ammonium hydroxide
Our own Ammonium hydroxide safety data sheet walks through all sixteen sections of the published data. What it is not is the document an inspector asks for: an SDS is issued for a product by its supplier, so the sheet covering the grade actually standing in your store exists only in that supplier’s version. Collecting those and keeping them current as suppliers revise them is a separate job.
04 · Precautionary statements
Ammonium hydroxide precautionary statements
CLP Annex VI assigns 8 precautionary statements to Ammonium hydroxide. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Ammonium hydroxide name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | амоняк ....% |
| Spanish español | Amoniaco al … % |
| Czech čeština | amoniak, roztok …% |
| Danish dansk | ammoniak ....% |
| German Deutsch | Ammoniak ….% Ammoniaklösung … % |
| Estonian eesti | ammoniaak ….% |
| Greek ελληνικά | αμμωνία … % |
| English English | ammonia ….% |
| French français | ammoniac …% |
| Croatian hrvatski | amonijak ....% |
| Italian italiano | ammoniaca ....% |
| Latvian latviešu | amonjaks …. % |
| Lithuanian lietuvių | ….% amoniakas |
| Hungarian magyar | ammónia ….% |
| Maltese Malti | ammonijaku …% |
| Dutch Nederlands | ammoniak …. % |
| Polish polski | amoniak, roztwór … % |
| Portuguese português | amoníaco a ...% |
| Romanian română | amoniac ….% |
| Slovak slovenčina | amoniak ….% |
| Slovenian slovenščina | amonijak … % |
| Finnish suomi | ammoniakki ....% |
| Swedish svenska | ammoniak ….% |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Ammonium hydroxide GHS label elements
Everything CLP Annex VI fixes for Ammonium hydroxide, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Ammonium hydroxide
- Causes severe skin burns and eye damage.
- Very toxic to aquatic life.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- Immediately call a POISON CENTER/doctor/…
- Do NOT induce vomiting.
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Ammonium hydroxide in the GHS label constructor →
07 · Health hazards
Ammonium hydroxide health hazards and exposure limits
Ammonium hydroxide hazard summary
Corrosive to skin; [Quick CPC] High inhalation exposure can cause pulmonary edema. [HSDB] A corrosive substance that can cause injury to the skin, eyes and respiratory tract; Inhalation of high concentrations may cause laryngeal edema, respiratory tract inflammation, and pneumonia; Prolonged or repeated exposure to vapor or aerosol may cause injury to lungs; [ICSC] Solution of <28% aqueous ammonia: Causes burns; Short-term exposure causes smarting of the skin and first-degree burns; Second-degree burns can result from extended exposure; [CHRIS] Human inhalation of 408 ppm causes focal fibrosis (pneumoconiosis) and acute pulmonary edema; [RTECS] Causes burns; A lachrymator; Toxic by ingestion; Inhalation may cause corrosive injuries to upper respiratory tract and lungs; [Aldrich MSDS] See Ammonia.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Ammonium hydroxide occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| IDLH | 300 ppm /Ammonia/ | Hazardous Substances Data Bank (HSDB) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
Ammonium hydroxide properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Ammonium hydroxide boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 38 °C (100.4 °F) | ICSC | |
| 36 °C (96.8 °F) | at 760 mmHg | DOE PAC |
Ammonium hydroxide melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -58 °C (-72.4 °F) | ICSC | |
| -77 °C (-106.6 °F) | DOE PAC |
Ammonium hydroxide density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.9 g/cm³ | ICSC | |
| 0.9 g/cm³ | at 25 °C | DOE PAC | |
| About 0.90 @ 25 °C/25 °C | at 25 °C | HSDB |
Ammonium hydroxide solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Exists only in solution | HSDB | |
| Solubility in water: miscible | ICSC |
Ammonium hydroxide vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 360.03 mmHg | at 20 °C | ICSC |
| 2160 mmHg | at 25 °C | HSDB |
Ammonium hydroxide vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 0.6 (air = 1) | ICSC |
Ammonium hydroxide odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor Threshold Low: 50.0 [ppm] | Haz-Map | |
| [HSDB] Odor threshold from CHRIS | Haz-Map |
Ammonium hydroxide corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Dissolves copper, zinc | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Handling and storage
Ammonium hydroxide storage and handling
Ammonium hydroxide reactive group
CAMEO Chemicals places Ammonium hydroxide in the reactive groups Bases, Weak, Water and Aqueous Solutions. Compatibility with other chemicals is worked out from the group, not from the individual substance — which is why two substances you have never seen react can still be flagged as a pair that must be separated.
A reactive group is a CAMEO Chemicals (US NOAA) grouping, not a GHS hazard class: it has no code, no category and no legal force. It is what the storage compatibility matrix on this site computes from.
Ammonium hydroxide safe storage
Store in an area without drain or sewer access. Separated from food and feedstuffs. See Chemical Dangers. Cool. Well closed. Keep in a well-ventilated room. Provision to contain effluent from fire extinguishing.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Ammonium hydroxide storage conditions
Keep cool in strong glass, plastic, or rubber stoppered bottles not completely filled. /Ammonia water: 28-29%/
Source: Hazardous Substances Data Bank (HSDB)
Ammonium hydroxide incompatible materials
CAUSTIC LIQ FORMS EXPLOSIVE CMPD WITH MANY HEAVY METALS SUCH AS SILVER, LEAD, ZINC, & THEIR SALTS, ESPECIALLY HALIDE SALTS.
Source: Hazardous Substances Data Bank (HSDB)
Ammonium hydroxide reactivity
AMMONIUM HYDROXIDE reacts exothermically with acids. Evolves toxic gaseous ammonia with strong bases. Reacts extremely violently with dimethyl sulfate [NFPA 491M 1991]. Reacts with aqueous silver nitrate sodium hydroxide to give a black precipitate of silver nitride. Such a precipitate can explode on stirring [MCA Case History 1554 1968]. Aqueous ammonia and Hg react to form an explosive solid, likely a fulminate. (Thodos, G. Amer. Inst. Chen. Engrs. J., 1964, 10, 274.).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Ammonium hydroxide in the storage compatibility matrix →
10 · Transport
Ammonium hydroxide UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
The same CAS number is shipped under more than one UN number. Which entry applies follows from the form and the concentration of the consignment — read the proper shipping name, not the CAS.
Ammonium hydroxide under UN 2073 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| AMMONIA SOLUTION, relative density less than 0.880 at 15 °C in water, with more than 35 % but not more than 50 % ammonia | 2 | 4A | — | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 2 is “Gases” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 35 percent but not more than 50 percent ammonia | 2.2 | — | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 2.2 is “Non-flammable compressed gas” (49 CFR 173.2).
Ammonium hydroxide under UN 2672 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| AMMONIA SOLUTION, relative density between 0.880 and 0.957 at 15 °C in water, with more than 10 % but not more than 35 % ammonia | 8 | C5 | III | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 8 is “Corrosive substances” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Ammonia solution, relative density between 0.880 and 0.957 at 15 degrees C in water, with more than 10 percent but not more than 35 percent ammonia | 8 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 8 is “Corrosive material” (49 CFR 173.2).
Ammonium hydroxide under UN 3318 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| AMMONIA SOLUTION, relative density less than 0.880 at 15 °C in water, with more than 50 % ammonia | 2 | 4TC | — | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 2 is “Gases” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia | 2.3 | — | |
| Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia | 2.2 | — | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 2.3 is “Poisonous gas” (49 CFR 173.2).
11 · Questions
Ammonium hydroxide — frequently asked questions
What is the CAS number of Ammonium hydroxide?
The CAS number of Ammonium hydroxide is 1336-21-6. Its EC number is 215-647-6.
What does a Ammonium hydroxide label have to show?
Under CLP Annex VI the label for Ammonium hydroxide carries the pictograms Corrosion and Environment and the signal word is Danger.
Is Ammonium hydroxide flammable?
CLP Annex VI assigns Ammonium hydroxide no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it.
Is Ammonium hydroxide a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Ammonium hydroxide. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.
What is the boiling point of Ammonium hydroxide?
The boiling point reported for Ammonium hydroxide is 38 °C (100.4 °F) (ICSC).
What is the melting point of Ammonium hydroxide?
The melting point reported for Ammonium hydroxide is -58 °C (-72.4 °F) (ICSC).
How should Ammonium hydroxide be stored?
Keep cool in strong glass, plastic, or rubber stoppered bottles not completely filled. /Ammonia water: 28-29%/ (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Ammonium hydroxide
Keep going: substances starting with A, or search the whole database by name, CAS number, pictogram or signal word.
Next