Ammonium Hydroxide

1Identification

Name

Ammonium Hydroxide

IUPAC name

azanium hydroxide

CAS number

1336-21-6

EC number

215-647-6

Molecular formula

H5NO

Molecular weight

35.046 g/mol

InChIKey

VHUUQVKOLVNVRT-UHFFFAOYSA-N

SMILES

[NH4+].[OH-]

PubChem CID

14923

Synonyms

ammonium hydroxide, Ammonia water, Ammonia aqueous, Aquammonia, Ammonia, aqua, Household ammonia, NH4OH, Ammonia, monohydrate, Ammonia water 29%, SX 1 (ammonia water), Ammonium hydroxide ((NH4)(OH)), Hydroxide, Ammonium, RefChem:6613, Ammonium hydrate

Recommended uses

• CIR ingredient: Ammonium Hydroxide
  Cosmetic Ingredient Review (CIR)
• Used in manufacturing rayon and other textiles, pharmaceuticals, paper, rubber, detergents, inks, and other organic chemicals; Also used in photographic development, metal extracting, and water purification; Also used as a fertilizer for direct application to the soil, a household cleanser, and a food additive; [HSDB] Also used as a mordant in textile dyeing; [www.ci.tucson.az.us/arthazards/medium.html] Other uses include leather processing and electroplating; [OECD SIDS] Used to regulate acidity in foods; [JECFA]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Electroplating [Category: Plate] Pulp and Paper Processing [Category: Industry] Textiles (Fiber & Fabric Manufacturing) [Category: Industry] Sewer and Wastewater Treatment [Category: Industry] Leather Tanning and Processing [Category: Industry] Photographic Processing [Category: Other] Textiles (Printing, Dyeing, or Finishing) [Category: Industry] Farming (Respiratory Hazards) [Category: Industry] Metal Extraction and Refining [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Intermediate Chelating agent Solids separation (precipitating) agent, not otherwise specified Adhesion/cohesion promoter Etching agent Laboratory chemicals Oxidizing agent Surface modifier Brightener Fixing agent (mordant) Cleaning agent Not Known or Reasonably Ascertainable Corrosion inhibitor Catalyst Soil amendments (fertilizers) Reducing agent Semiconductor and photovoltaic agent Processing aids not otherwise specified pH regulating agent Plating agent Vapor pressure modifiers Chemical reaction regulator Flavoring and nutrient Solvent Binder Other
  EPA Chemical Data Reporting (CDR)
• Other Binder Dispersing agent Opacifer pH regulating agent Processing aids not otherwise specified Semiconductor and photovoltaic agent Tanning agents not otherwise specified Reducing agent Preservative Soil amendments (fertilizers) Not Known or Reasonably Ascertainable Catalyst Cleaning agent Fixing agent (mordant) Laboratory chemicals Etching agent Adhesion/cohesion promoter Chelating agent Intermediate
  EPA Chemical Data Reporting (CDR)

Use categories: EPA Safer Chemical Functional Use Classes -> Specialized Industrial Chemicals · Safer Chemical Classes -> Yellow triangle - The chemical has met Safer Choice Criteria for its functional ingredient-class, but has some hazard profile issues · Food Additives -> ACIDITY_REGULATOR -> JECFA Functional Classes · Cosmetics -> Buffering; Denaturant

Description

• Ammonium hydroxide appears as a colorless aqueous solution. Concentration of ammonia ranges up to approximately 30%. Ammonia vapors (which arise from the solution) irritate the eyes.
  CAMEO Chemicals
• Ammonium hydroxide is a solution of ammonia in water. It has a role as a food acidity regulator.
  ChEBI
• The CIR Expert Panel concluded that Ammonia and Ammonium Hydroxide are safe as used in hair dyes and colors and safe in cosmetics applied directly to the skin in the present practices of use and concentration described in the safety assessment when formulated to be non-irritating.
  Cosmetic Ingredient Review (CIR)

2Hazard identification

Signal word

Danger

Pictograms

GHS05, GHS09

Classification source

Regulation (EC) No 1272/2008 of the European Parliament and of the Council

Precautionary statements

Other reported classifications

6 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

Health hazards

• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination. (ERG, 2024)
  CAMEO Chemicals
• · TOXIC and/or CORROSIVE; may be fatal if inhaled, ingested or absorbed through skin. · Vapors are extremely irritating and corrosive. · Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. · Fire will produce irritating, corrosive and/or toxic gases. · Runoff from fire control or dilution water may cause environmental contamination.
  Emergency Response Guidebook (ERG)
• · TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death. · Contact with molten substance may cause severe burns to skin and eyes. · Avoid any skin contact. · Fire may produce irritating, corrosive and/or toxic gases. · Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.
  Emergency Response Guidebook (ERG)

Fire hazards

• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion or sodium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2024)
  CAMEO Chemicals
• · Some may burn but none ignite readily. · Vapors from liquefied gas are initially heavier than air and spread along ground. · Some of these materials may react violently with water. · Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices. · Containers may explode when heated. · Ruptured cylinders may rocket. · For UN1005: Anhydrous ammonia, at high concentrations in confined spaces, presents a flammability risk if a source of ignition is introduced.
  Emergency Response Guidebook (ERG)
• · Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. · Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). · Corrosives in contact with metals may evolve flammable hydrogen gas. · Containers may explode when heated. · For electric vehicles or equipment, GUIDE 147 (lithium ion or sodium ion batteries) or GUIDE 138 (sodium batteries) should also be consulted.
  Emergency Response Guidebook (ERG)

Hazards 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;
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• The major hazards encountered in the use and handling of ammonium hydroxide stem from its toxicologic properties. Toxic by all routes (ie, inhalation, ingestion, and dermal contact), exposure to this colorless, intensely pungent-smelling liquid may occur from its use in fertilizers, dyes, explosives, plastics, cleansing agents, fibers, and resins. Effects from exposure may include extreme irritation of the eyes and mucous membranes, contact burns to the skin and eyes, and life-threatening pulmonary edema. In activities and situations where over-exposure is possible, wear a self-contained breathing apparatus, and protective clothing (including full face protection).
  Hazardous Substances Data Bank (HSDB)

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Refer to the "General First Aid" section. Specific First Aid: For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required. (ERG, 2024)
  CAMEO Chemicals
• General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).
  Emergency Response Guidebook (ERG)

Symptoms of exposure

• Cough. Sore throat. Burning sensation. Laboured breathing. Shortness of breath.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness. Pain. Blisters. Serious skin burns.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness. Pain. Blurred vision. Severe burns.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

Not available in the public sources we compile. Check Section 5 of the supplier's SDS.

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary. FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
  CAMEO Chemicals
• Immediate precautionary measure · Isolate spill or leak area for at least 100 meters (330 feet) in all directions. Spill · For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances. · For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary. Fire · If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions.
  Emergency Response Guidebook (ERG)

Spill cleanup

• Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment. Cautiously neutralize spilled liquid with dilute acid such as dilute sulfuric acid. Wash away remainder with plenty of water.
  ILO-WHO International Chemical Safety Cards (ICSCs)

7Handling and 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.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Keep cool in strong glass, plastic, or rubber stoppered bottles not completely filled. /Ammonia water: 28-29%/
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)
  CAMEO Chemicals
• Employees working in areas where /ammonium hydroxide/ is used must be trained in escape methods and in the use of safety equipment, including goggles, gas masks, showers, eye fountains, water hoses, exits, lifelines and first-aid equipment ... Equipment must by constantly inspected to prevent accidents. All valves should be labeled to prevent accidental opening. If a contaminated area must be entered, a full-face airline mask or self-contained oxygen mask must be worn.
  Hazardous Substances Data Bank (HSDB)
• [ACGIH; Guidelines Select of Chem Protect Clothing Volume #1 Field Guide p.67 (1983)] Some data suggest breakthrough times for ammonium hydroxide of approximately an hour or more for natural rubber. For ammonium hydroxide (30-70%), breakthrough times greater than one hour have been reported (normally) by two or more testers for viton.
  Hazardous Substances Data Bank (HSDB)
• For ammonium hydroxide, two or more testers have reported (normally) breakthrough times for neoprene to be greater than one hour.
  Hazardous Substances Data Bank (HSDB)

9Physical and chemical properties

10Stability and reactivity

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.).
  CAMEO Chemicals
• Water soluble. Generates a small amount of heat when diluted with water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• CAUSTIC LIQ FORMS EXPLOSIVE CMPD WITH MANY HEAVY METALS SUCH AS SILVER, LEAD, ZINC, & THEIR SALTS, ESPECIALLY HALIDE SALTS.
  Hazardous Substances Data Bank (HSDB)
• With sodium hydroxide and silver nitrate: During preparation of an oxidizing agent on a larger scale than described, addition of warm sodium hydroxide solution to warm ammoniacal silver nitrate with stirring caused immediate precipitation of black silver nitride, which exploded. Similar incidents had been reported previously, including one where explosion appeared to be initiated by addition of Devarda's alloy (Al-Cu-Zn).
  Hazardous Substances Data Bank (HSDB)
• Incompatible with acrolein, nitromethane, acrylic acid, chlorosulfonic acid, dimethyl sulfate, halogens, (Au + aqua regia), HCl, HF, HNO3, oleum, beta-propiolactone, propylene oxide, ... Ag2O, (Ag2O + C2H5OH), AgMnO4, H2SO4.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Short-term exposure effects

• The substance is corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion. Inhalation of high concentrations of the vapour may cause laryngeal oedema, inflammation of the respiratory tract and pneumonia. Exposure could cause asphyxiation due to swelling in the throat. The effects may be delayed.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• Repeated or prolonged inhalation may cause effects on the lungs.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.
  Hazardous Substances Data Bank (HSDB)
• Neutralization: Put into large vessel containing water. Neutralize with hydrochloric acid. ... Recommendable methods: Landfill, ... chemical treatment. Not recommendable method: Thermal destruction. Peer-review: Small amounts only: Landfill, great dilution before discharge to sewer. Large amounts of ammonia in landfill leachate may make disposal of leachate difficult. (Peer-review conclusions of an IRPTC expert consultation (May 1985))
  Hazardous Substances Data Bank (HSDB)

14Transport information

UN numbers: UN 2672, UN 2073, UN 1005

Shipping name

• UN 2672; Ammonia solutions density (specific gravity) between 0.880 and 0.957 at 15 °C in water with more than 10% but not more than 35% ammonia.
  Hazardous Substances Data Bank (HSDB)
• UN 2073; Ammonia solutions density (specific gravity) less than 0.880 at 15 °C in water, with more than 35% but not more than 50% ammonia.
  Hazardous Substances Data Bank (HSDB)

DOT label

• Corrosive
  CAMEO Chemicals

UN classification

• UN Hazard Class: 8; UN Pack Group: III
  ILO-WHO International Chemical Safety Cards (ICSCs)

Emergency Response Guidebook

• 2073 125
  Emergency Response Guidebook (ERG)
• 2672 154
  Emergency Response Guidebook (ERG)

How DOT hazard classes work →

15Regulatory information

• Residues of ammonium hydroxide are exempted from the requirement of a tolerance when used as a solvent, cosolvent, neutralizer, or solublizing agent in accordance with good agricultural practices as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest.
  Hazardous Substances Data Bank (HSDB)
• Designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance.
  Hazardous Substances Data Bank (HSDB)
• Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).
  Hazardous Substances Data Bank (HSDB)
• Ammonium hydroxide used as a general purpose food additive in animal drugs, feeds, and related products is generally recognized as safe when used in accordance with good manufacturing or feeding practice.
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 14923 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.