1-methylcyclopropene

1-methylcyclopropene	Last updated: 19/09/2024
(Also known as: 1-MCP; MCP; methylcyclopropene)

SUMMARY

1-methylcyclopropene is a plant growth regulator used to extend the life of cut ornamentals. It is moderately soluble in water, highly volatile and has some potential for leaching to groundwater. It is not persistent in soil systems but may, under certain conditions, persist in aquatic systems. It has no herbicidal activity. It is relatively non-toxic to mammals, although it may bioaccumulate. There are gaps in knowledge regarding its toxicity to biodiversity but there is data showing that it is moderately toxic to fish and algae. It is highly toxic to earthworms.

Data 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.

Environmental fate	Ecotoxicity	Human health
Environmental fate High alert: Drainflow: Mobile	Ecotoxicity High alert: Birds acute ecotoxicity: High; Earthworms acute ecotoxicity: High	Human health Low alert

GENERAL INFORMATION

Description

A gas used as a plant regulator to extend the life of cut and potted flowers, other ornamental plants and fruit.

Example pests controlled

Ripening processes

Example applications

Harvested fruit and vegetables especially apples; Ornamentals especially cutflowers, potted flowering plants, spring bedding, nursery andfoliage plants

Efficacy & activity

Efficiacy has been tested experimentally and in practice. The substance has been in active use for many years.

Availability status

Current

Introduction & key dates

1999, first USA registration

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/07/2034

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Netherlands/Portugal

Date EC 1107/2009 inclusion expires

31/07/2034

EU Candidate for substitution (CfS)

Yes - low ADI / ARfD / AOEL

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, Canada

Chemical structure

Isomerism

None

Chemical formula

C₄H₆

Canonical SMILES

CC1=CC1

Isomeric SMILES

International Chemical Identifier key (InChIKey)

SHDPRTQPPWIEJG-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C4H6/c1-4-2-3-4/h2H,3H2,1H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Plant Growth Regulator

Substance groups

Fumigant PGR

Minimum active substance purity

980 g kg⁻¹

Known relevant impurities

EU dossier 2024 - 3-CMP <0.3 g kg⁻¹; 1-CMP <0.2 g kg⁻¹; heptane

Substance origin

Synthetic

Mode of action

Inhibits the effects of ethylene on ripening

CAS RN

3100-04-7

EC number

608-567-1

CIPAC number

767

US EPA chemical code

224459

PubChem CID

151080

Molecular mass

54.09

PIN (Preferred Identification Name)

IUPAC name

1-methylcyclopropene

CAS name

1-methylcyclopropene

Other status information

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

Product is a white powder which then releases a colourless gas with faint sweet odour

Formulations

Property

Value

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

Landseer
Rohm and Hass
AgroFresh Inc,
Janssen

Example products using this active

SmartFresh
LupoFresh
EthylBloc
SmartTabs

Formulation and application details

Usually supplied in powder form for mixing with water which then releases the 1-MCP gas for fumigation within a closed space.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

137

Moderate

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

2450

n-Heptane

2250

Xylene

12500

Ethyl acetate

11000

Methanol

Melting point (°C)

-100

Boiling point (°C)

4.7

Degradation point (°C)

260

Flashpoint (°C)

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

2.51 X 10⁰²

Calculated

Log P

2.4

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

0.634

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

2.00 X 10⁰⁸

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)

4.39 X 10^-09

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Gas phase: 205nm=70.9; 290nm=0.119

Surface tension (mN m⁻¹)

Not applicable

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier estimated data

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

Stable

Note

Stable pH 5 to pH 9 at 20 °C. Rapid at elevated temperatures ~50 °C.

Water-sediment DT₅₀ (days)

Water 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)

Mobile

K_oc (mL g⁻¹)

42.7

Notes and range

EU dossier estimated data

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.79

Calculated

Transition state

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Value

1.34 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

methylally alcohol

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

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)

> 81

Colinus virginianus

High

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

5.0

Eisenia foetida corr

High

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

2.0

Eisenia foetida corr

Moderate

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

=> 300

Various plants n=10
Seedling emergence, ER₅₀
as g ha⁻¹

=> 300

Various plants n=10
Vegatative vigour, ER₅₀
as 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)

> 10.0

Apis mellifera as inhalation ppm

Moderate

Chronic

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) as Mortality LR₅₀

> 300

Chrysoperla carnea

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ ppm

10.0

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ ppm

10.0

Typhlodromus pyri

Beneficial insects (Ground beetles) as Mortality LR₅₀

> 300

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

> 0.966

Oncorhynchus mykiss

Moderate

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

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

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

> 0.776

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

> 5.8

Lemna gibba

Moderate

Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)

> 0.838

Selenastrum capricornutum

Moderate

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Intermediate (class II)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

>= 5.12

Rat

Other Mammal toxicity endpoints

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

0.02

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

0.12

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

0.12

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

0.04

Dermal penetration studies (%)

0.05-10

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Minimal as normally only used inside commercial premises
Small risk from digestion of treated food commodities
Source: US EPA

Occupational

Minimal - user should not be present during plant treatment which should be done in small enclosed spaces such as glasshouses

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Not allocated

Mammalian dose elimination route and rate

Rapidly excreted via expelled air. No unchanged substance in excreta.

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Possibly slight effects on some haemathological parameters

Handling issues

Property

Value and interpretation

General

Non-oxidising
Flammable
Auto-ignition at 188-191 DegC

CLP classification 2013

None allocated

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

1-methylcyclopropene

French

1-methylcyclopropene

German

1-Methylcyclopropen

Danish

1-methylcyclopropene

Italian

1-metilciclopropene

Spanish

1-metilciclopropene

Greek

Polish

1-metylocyklopropen

Swedish

Hungarian

Dutch

1-methylcyclopropeen

Norwegian

Record last updated:	19/09/2024
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