Bromomethane

Bromomethane	Last updated: 24/02/2026
(Also known as: methyl bromide; monobromomethane; methyl fume)

SUMMARY

Bromomethane is a multi-action plant protection agent used as a fumigant. It is highly soluble in water and highly volatile. It may be persistent in soil systems depending on local conditions but is not normally persistent in water systems. It tends to be moderately toxic to most fauna. Bromomethane is moderately toxic to mammals if ingested and is considered to be a reproduction/developmental toxin as well as being neurotoxic and an irritant.

Hazard alerts

The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.

PHT: Environmental fate	PHT: Ecotoxicity	PHT: Human health	Highly Hazardous Pesticide
Environmental fate High alert: Drainflow: Mobile	Ecotoxicity High alert: Birds acute ecotoxicity: High	Human health High alert: Mammals chronic toxicity: High; Genotoxic; Reproduction/development effects; Neurotoxicant	Highly Hazardous Pesticide (HHP) Type I alert Highly Hazardous Pesticide (HHP) Type II alert

GENERAL INFORMATION

Description

A multiaction fumigant used to control insects, weeds, rodents and pathogens

Example pests controlled

Termites; Rats; Mice; Nematodes; Soil-borne diseases; Weed seedlings

Example applications

Agricultural commodities; Non-agricultural situations including commercial structures; Grain elevators; Clothes; Furniture

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

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

Also used in

Australia; USA; Morocco; Japan

Chemical structure

Isomerism

None

Chemical formula

CH₃Br

Canonical SMILES

CBr

Isomeric SMILES

International Chemical Identifier key (InChIKey)

GZUXJHMPEANEGY-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/CH3Br/c1-2/h1H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
bromomethane	-

General status

Biopesticide type

Soil sterilant; Insecticide

Substance groups

Fumigant pesticide; Halogenated aliphatic herbicide

Minimum active substance purity

990 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Natural

Mode of action

Respiratory action, highly toxic

Substance source

A naturally occurring component of the environment, with oceans representing the largest natural source. It is formed by algae and kelp.

Uses

Crop protection; General pest management

Target pests

Termites; Rats; Mice; Nematodes; Soil-borne diseases; Weed seedlings

Target host

Agricultural commodities; Non-agricultural situations including commercial structures; Grain elevators; Clothes; Furniture

Farming system suitability

CAS RN

74-83-9

EC number

200-813-2

CIPAC number

128

US EPA chemical code

53201

PubChem CID

6323

CLP index number

602-002-00-2

Molecular mass

94.95

PIN (Preferred Identification Name)

bromomethane

IUPAC name

bromomethane

CAS name

bromomethane

Global Governance status: Listed (✓) under

UK Poisons List Order 1972	Rotterdam Convention	Montreal Protocol
✓Yes The Poisons List Order 1972	✓ (Annex II)Yes (Annex II) Rotterdam Convention	✓Yes Montreal Protocol
Stockholm Convention	OSPAR	EU Water Framework Directive
XNo Stockholm Convention	XNo OSPAR	XNo EU Water Framework Directive

Relevant Environmental Water Quality Standards

Forever chemical

Highly Hazardous Pesticide (HHP)

Type I

Yes [; ; ]

Type II

Yes [; ; ; ]

Other status information

Marine pollutant; PAN Bad Actor Chemical

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Fungicide Resistance Class (FRAC MOA class)

Not known

Examples of recorded resistance

Sitophilus granarius, Sitophilus granarius, Tribolium confusum

Physical state

Colourless gas

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Circa 1935, introduced

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

Dow AgroSciences
Hefei TNJ Chemical Industry Co.,Ltd.
Ameribrom Inc.

Example products using this active

50-50 Preplant Soil Fumigant
Brom-O-gas
Coastal dowfume

Formulation and application details

Gaseous formulation used for fumigation treatments

Commercial production

It is manufactured for agricultural and industrial use by treating methanol with bromine in the presence of sulphur or hydrogen suphfide

Impact on climate of production and use

There are no precise, published data on the GHG emissions associated with the production of bromomethane. However, it can be estimated from other halogenated chemicals. Methanol production emits around 0.5–1.0 tonnes CO₂e per tonne. The synthesis of bromine or hydrogen bromide emits 1.0–2.0 tonnes CO₂e. Reaction and purification would add a further 0.5–1.0 tonnes CO₂e. This gives a very approximate total of 2–4 tonnes CO₂e per tonne of bromomethane.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C at pH 7 (mg l⁻¹)

13200

High

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

718000

Acetone

228100

Kerosene

925000

Ethyl acetate

Melting point (°C)

-93.7

Boiling point (°C)

3.56

Degradation point (°C)

Flashpoint (°C)

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

8.13 X 10⁰¹

Calculated

Log P

1.91

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

3.97

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

190000000

Highly volatile. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

13625.1

Volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

Volatilisation is potentially a concern for short and long range air transport

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

202nm = 3.1

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Moderately persistent

DT₅₀ (lab at 20 °C)

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

Moderately persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies estimated values DT₅₀ range 2.5-47 hours, DT₉₀ 30.8 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

4.8

Note

Published literature RL₅₀ range 1.0-12.3 days, 2 field & undercover grown crops, various matrices, n=3

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

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

Value

Non-persistent

Note

pH and temperature sensitive

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)

2.48

Mobile

K_oc (mL g⁻¹)

Notes and range

EU dossier K_d range 2.07-2.98 mL g⁻¹, K_oc range 37.7-41.4 mL g⁻¹, Soils=4

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)

104

Rat

Moderate

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

0.13

Dog 1-yr

High

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

7.0

Rat

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

Colinus virginianus

High

Birds - Short term dietary LC₅₀ (mg kg⁻¹ bw d⁻¹)

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)

> 50

Moderate

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)

Beneficial insects (Butterflies)

Contact

Notes

Oral

Notes

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

3.9

Oncorhynchus mykiss

Moderate

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

> 0.32

Oryzias latipes

Moderate

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

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

2.6

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) (48 hr EC₅₀)

3.2

Scenedesmus quadricauda

Moderate

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

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

Regulatory Threshold Levels (RTLs)

Note: These RTLs have been calculated using the regulatory approach used in the European Union and based on ecotoxocity values in the PPDB.

Species group

RTL

Notes

Mammals

0.026

Worst case of acute and chronic mammals

Birds

7.3

Worst case of acute and chronic birds

Soil organisms

No data

No data for acute and chronic earthworms

Terrestrial plants

No data

No data for non-target plants vegetative vigour and seedling emergence

Pollinators

No data

No data for contact and oral honeybees

Arthropods

No data

No data for parasitic wasps and predatory mites

Fish

0.032

Worst case of temperate acute and chronic fish

Aquatic invertebrates

0.026

Worst case of temperate acute and chronic aquatic invertebrates

Aquatic plants

0.32

Worst case of free-floating plants, rooted plants, acute and chronic algae

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)

104

Rat

Moderate

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

0.13

Dog 1-yr

High

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

7.0

Rat

Moderate

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

3.0

Rat 4 hr (whole body)

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 (%)

100

default

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Acceptable if PPE/PPC used

Mammalian dose elimination route and rate

Health issues

Specific human health issues (hazard-based)

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Mutagenic potential; Suspected of causing genetic defects
Highly toxic
Brain, kidney, respiratory toxicant
IARC Group 3 carcinogen - not classifiable

Handling issues

Property

Value and interpretation

General

Highly corrosive,Flammable gas
IMDG Transport Hazard Class 2

CLP classification 2013

Health: H301, H315, H319, H335, H341, H373
Environment: H400, H420

WHO Classification

Ib (Fumigant) (Highly hazardous)

UN Number

UN1581

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

bromomethane

French

bromure de methyle

German

Methylbromid

Danish

methylbromid

Italian

bromuro di metile

Spanish

bromuro de metil

Greek

methylbromide

Polish

bromek metylu

Swedish

Hungarian

metil-bromid

Dutch

broommethaan

Norwegian

Record last updated:	24/02/2026
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

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