Ammonium hydroxide

Ammonium hydroxide	Last updated: 18/09/2025
(Also known as: ammonia solution; aqua ammonia; ammonium hydroxyde)

SUMMARY

Ammonium hydroxide is an inorganic herbicide, fungicide and microbiocide.It is non-volatile and highly soluble in water. Ammonium hydroxide has a moderate mammalian toxicity and there is some risk of bioaccumulation. It is a recognised irritant. It is highly toxic to fish and moderately toxic to aquatic invertebrates.

Hazard alerts

The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
Environmental fate Low alert: Potential for particle bound transport: Low Warning: Significant data are missing	Ecotoxicity High alert: Fish acute ecotoxicity: High Warning: Significant data are missing	Human health Moderate alert: Mammals acute toxicity: Moderate Warning: Significant data are missing

GENERAL INFORMATION

Description

An inorganic herbicide, fungicide and microbiocide used as a general purpose sterilant

Example pests controlled

Coccidial oocysts; General bacteria

Example applications

Surfaces; Building structures

Efficacy & activity

Appearance and life cycle

Taxonomic classification

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

GB LERAP status

No UK approval for use as a plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Not applicable

Date EC 1107/2009 inclusion expires

Expired

EU Candidate for substitution (CfS)

Not applicable

Listed in EU database

Yes

Approved for use (✓) under EC 1107/2009 in the following EU Member States

ATAustria	BEBelgium	BGBulgaria	CYCyprus	CZCzech Republic	DEGermany	DKDenmark	EEEstonia	ELGreece

ESSpain	FIFinland	FRFrance	HRCroatia	HUHungary	IEIreland	ITItaly	LTLithuania	LULuxembourg

LVLatvia	MTMalta	NLNetherlands	PLPoland	PTPortugal	RORomania	SESweden	SISlovenia	SKSlovakia

Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries

ISIceland	NONorway

Additional information

Known to be also used in the following countries

Chemical structure

Isomerism

None

Chemical formula

NH₄OH

Canonical SMILES

[NH4+].[OH-]

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

VHUUQVKOLVNVRT-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/H3N.H2O/h1H3;1H2

2D structure diagram/image available?

Yes

General status

Biopesticide type

Herbicide; Other substance

Other bioactivity & uses

Microbiocide

Substance groups

Inorganic compound

Minimum active substance purity

Known relevant impurities

Substance origin

Natural

Mode of action

As a fungicide it is a protectant, inhibiting fungal spores and pathogens from entering the host tissues

Substance source

Ammonium hydroxide is found naturally in the air, water, soil, plants and naimals

Uses

Non-agricultural

Target pests

Coccidial oocysts; General bacteria

Target host

Surfaces; Building structures

Farming system suitability

Not normally used in agriculture

CAS RN

1336-21-6

EC number

215-647-6

CIPAC number

8013

US EPA chemical code

PubChem CID

14923

CLP index number

007-001-01-2

Molecular mass

35.05

Chemical name

ammonium hydroxide

PIN (Preferred Identification Name)

IUPAC name

CAS name

Forever chemical

Other status information

US GRAS

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Colourless liquid

Commercial

Property

Value

Availability status

Current

Introduction & key dates

First agricultural use undocumented

Example manufacturers & suppliers of products using this active now or historically

Cenik Chemicals UK
Hawkins Inc. USA
KMG Chemicals, Inc.
HeGo Biotec GmbH

Example products using this active

Ammonia Liquor
Aqua Ammonia
Technical Grade Ammonium Hydroxide

Formulation and application details

Supplied as a liquid in various container sizes

Commercial production

Ammonium hydroxide is produced by dissolving ammonia gas into water, forming a weakly basic solution known as aqua ammonia. The process typically begins by cooling distilled water to enhance gas absorption, followed by introducing ammonia gas into the water using a gas absorption apparatus or sparger. This reaction is reversible and yields ammonium ions and hydroxide ions, resulting in ammonium hydroxide.

Impact on climate of production and use

The GHG emissions from manufacturing ammonium hydroxide are primarily tied to the production of its key input: anhydrous ammonia, which is synthesised via the energy-intensive Haber-Bosch process. This process has an estimated footprint of 1.8–2.0 kg CO₂e per kg of ammonia produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

1000000

at 25 °C

High

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

Flashpoint (°C)

Octanol-water partition coefficient at pH 7, 20 °C

2.19 X 10^-03

Calculated

Log P

-2.66

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

0.9

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

1.00 X 10^-10

Low volatility

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

4.09 X 10^-12

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.1

Non-persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

0.1

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Natural substance that rapidly disperses in the environment

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

350

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹ dw soil)

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic

Notes

Bumblebees (Bombus spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Other bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

0.024

Lepomis macrochirus

High

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

< 5

Ceriodaphnia dubia

Moderate

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Daphnia magna

Moderate

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Aquatic Plants (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

350

Rat

Moderate

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Health issues

Specific human health issues (hazard-based)

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Toxic
May cause corrosion to the esophagus and stomach with perforation and peritonitis
May cause rapid lowering of blood pressure

Handling issues

Property

Value and interpretation

General

Corrosive
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H314
Environment: H400

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

ammonium hydroxide

French

hydroxyde d'ammonium

German

Ammoniumhydroxid

Danish

ammoniumhydroxid

Italian

idrossido di ammonio

Spanish

hidróxido de amonio

Greek

Polish

wodorotlenek amonu

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	18/09/2025
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242