Dicyclopentadiene	Last updated: 12/01/2021
(Also known as: cyclopentadiene dimer; DCPD)

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SUMMARY

Dicyclopentadiene is manufacturered from high temperature cracking of petroleum fractions in an ethylene manufacturing process. It is used in the manufacturer of some pesticides, as a grass growth regulator and, in some instances, as a mammal repellent. It has a low aqueous solubility, is highly volatile and flammable, and may be environmentally persistent. It is moderately toxic to mammals via ingestion but more so if the vapour is inhaled. It may cause chemical burns in contact with the skin and is a recognised irritant. It is moderately toxic to many animal and plant species..

GENERAL INFORMATION

Description	An unclassified plant growth regulator, pesticide intermediate and animal repellent
Example pests controlled	Large mammals including dogs, cats, rats, rabbits, hares, deer; Grass growth
Example applications	Grass, Lawns, Turf
Efficacy & activity	-
Availability status	Obsolete
Introduction & key dates	-

UK regulatory status

UK COPR regulatory status	Not approved
Date COPR inclusion expires	Expired
UK LERAP status	No UK approval for use

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

Also used in

Also used in	-

Chemical structure

Isomerism	A chiral molecule
Chemical formula	C₁₀H₁₂
Canonical SMILES	C1C=CC2C1C3CC2C=C3
Isomeric SMILES	C\2=C\C3C1/C=C\C(C1)C3C/2
International Chemical Identifier key (InChIKey)	HECLRDQVFMWTQS-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C14H18N6O7S/c1-5-27-12(21)8-7-15-20(2)11(8)28(23,24)19-14(22)18-13-16-9(25-3)6-10(17-13)26-4/h6-7H,5H2,1-4H3,(H2,16,17,18,19,22)
2D structure diagram/image available?	Yes

General status

Pesticide type	Plant growth regulator, Repellent
Substance group	Hydrocarbon
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Various routes, acts as a repellent via odour but is also a stomach and vapour toxin
CAS RN	77-73-6
EC number	201-052-9
CIPAC number	8103
US EPA chemical code	-
PubChem CID	6492
Molecular mass	132.20
PIN (Preferred Identification Name)	-
IUPAC name	3a,4,7,7a-tetrahydro-4,7-methano-1H-indene
CAS name	dicyclopentadiene
Other status information	-
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	Not applicable
Herbicide Resistance Classification (WSSA)	Not applicable
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	White cyrstalline solid at room temperature in its pure form and has a characteristic odour. Commercial products may be a colourless liquid.

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	-
Example products using this active	Staehler Dow
Formulation and application details	Usually supplied as impregnated strips for tree use or as a solublecontrate for use as an aqueous spray

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		26.5	T4 T = UN EPFA database 4 = Verified data	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		-	-	-
Melting point (°C)		33.6	T4 T = UN EPFA database 4 = Verified data	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	6.03 X 1002	Calculated	-
	Log P	2.78	T4 T = UN EPFA database 4 = Verified data	Moderate
Bulk density (g ml⁻¹)		0.977	T4 T = UN EPFA database 4 = Verified data	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		1.3 X 1006	T4 T = UN EPFA database 4 = Verified data	Highly volatile
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		6.38 X 1003	V3 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 3 = Unverified data of known source	Volatile
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)	2000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	Very persistent
	DT₅₀ (lab at 20 °C)	2000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	Very persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Other sources: DT₅₀ 4-7 years
Dissipation rate RL₅₀ on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ on and in plant matrix	Value	-	-	-
	Note	-
Aqueous photolysis DT₅₀ (days) at pH 7	Value	Stable	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	Stable
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	Stable	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	Stable
	Note	-
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source	Slightly mobile
	Koc	1478
	Notes and range	Estimated
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		2.74	Calculated	Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	2.07 X 10-01	Calculated	-
	Note	-
Potential for particle bound transport index		High	Calculated	-
Potential for loss via drain flow		Slightly mobile	Calculated	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	221	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Whole fish	Threshold for concern
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		750	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source 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)		1010	V1 V = ChemID online databases / IPCS INCHEM (ChemID; IPCS INCHEM ) 1 = Estimated data with little or no verification Unknown species	Moderate
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		15.9	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		10.5	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (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)		-	-	-
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		-	-	-
Algae - Chronic 96 hour NOEC, growth (mg l⁻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)	Non-toxic	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Non-toxic
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 pollinators (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other pollinators (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		-	-	-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Other soil macro-organisms	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Other arthropod (1)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Soil micro-organisms		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-

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)		750	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		5080	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		1.0	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Rat 4 hr	-
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	Low risk to Europeans as no longer approved for use
	Occupational	Workers may become exposed via inhalation, skin absorption and ingestion
European MRLs		EU MRL pesticide database
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor No data found A0 A = Chromosome aberration (EFSA database) 0 = No data ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C0 C = Gene mutation (EFSA database) 0 = No data ; D0 D = Genome mutation (EFSA database) 0 = No data ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found XNo, known not to cause a problem No data found Respiratory tract irritant Skin irritant Skin sensitiser ✓Yes, known to cause a problem ✓Yes, known to cause a problem No data found Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		Moderately toxic Ingestion may damage nervous system and/or liver and kidney damage May cause chemical burns in contact with tissue,

Handling issues

Property	Value and interpretation
General	Mixtures of the vapour with air are explosive May react with oxygen Flammable
CLP classification 2013	Health: H302
EC Risk Classification	Xn - Harmful: R20/22 Xi - Irritant: R36/37/38 H - Handling risks: F11 N - Dangerous for the environment: R51, R53
EC Safety Classification	S2, S36/37, S61
WHO Classification	NL (Not listed)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	dicyclopentadiene
French	dicyclopentadiène
German	Dicyclopentadien
Danish	dicyclopentadien
Italian	diciclopentadiene
Spanish	diciclopentadiene
Greek	-
Polish	dicyklopentadien
Swedish	-
Hungarian	-
Dutch	-

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Record last updated:	12/01/2021
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