Hexachlorobenzene (Ref: ENT 1719)	Last updated: 27/10/2025
(Also known as: HCB; perchlorobenzene)

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SUMMARY

Hexachlorobenzene is a fumigant fungicide. It has a low aqueous solubility and is volatile with a low potential for leaching to groundwater. It may be very persistent in soil systems. Hexachlorobenzene las a low mammalian toxicity but a high potential to bioaccumulate. It may also be carcinogenic. It is highly toxic to fish and moderately toxic to birds, aquatic invertebrates, algae and earthworms.

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 High alert: Potential for particle bound transport: High Warning: Significant data are missing	Ecotoxicity High alert: Fish acute ecotoxicity: High; Fish chronic ecotoxicity: High; Daphnia chronic ecotoxicity: High	Human health High alert: Carcinogen; Endocrine disruptor

GENERAL INFORMATION

Description	An chlorinated hydrocarbon fungicide used to control bunt and a pesticide transformation product
Example pests controlled	Common and Dwarf bunt
Example applications	Wheat and some other cereals
Efficacy & activity	-

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

Also used in	-

Chemical structure

Isomerism	None
Chemical formula	C₆Cl₆
Canonical SMILES	C1(=C(C(=C(C(=C1Cl)Cl)Cl)Cl)Cl)Cl
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	CKAPSXZOOQJIBF-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C6Cl6/c7-1-2(8)4(10)6(12)5(11)3(1)9
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
hexachlorobenzene	-

General status

Pesticide type		Fungicide; Metabolite; Other substance
Metabolite Type		Soil
Other bioactivity & uses		Biocide; Wood preservative
Substance groups		Organochloride fungicide; Fumigant fungicide
Minimum active substance purity		-
Known relevant impurities		-
Substance origin		Synthetic
Mode of action		Fumigant action on fungal spores. It affects porphyrin synthesis and consequently the proteins involved in the metabolism and transport of oxygen.
CAS RN		118-74-1
EC number		204-273-9
CIPAC number		161
US EPA chemical code		061001
PubChem CID		8370
CLP index number		602-065-00-6
Molecular mass		284.80
PIN (Preferred Identification Name)		-
IUPAC name		perchlorobenzene
CAS name		hexachlorobenzene
Listed (✓) under		UK Poisons List Order 1972 Rotterdam Convention Montreal Protocol XNo The Poisons List Order 1972 ✓ (Annex II;III)Yes (Annex II;III) Rotterdam Convention XNo Montreal Protocol Stockholm Convention OSPAR EU Water Framework Directive ✓Yes Stockholm Convention ✓ (Section B)Yes (Section B) OSPAR ✓ Yes EU Water Framework Directive
Relevant Environmental Water Quality Standards		EU Directive 2008/105/EC EQS surface waters: annual average 0.01 µg l⁻¹; max measured 0.05 µg l⁻¹ UK Statutory standard for the protection of aquatic life in inland, coastal and territorial waters: 0.03 µg l⁻¹ as annual average Other standards are also available
Forever chemical		-
Highly Hazardous Pesticide (HHP)	Type I	Yes [ C1 Criterion 1: Pesticide active ingredients that meet the criteria of classes Ia or Ib of the WHO Recommended Classification of Pesticides by Hazard ; C2 Criterion 2: Pesticide active ingredients that meet the criteria of carcinogenicity Categories 1A and 1B of the Globally Harmonized System on Classification and Labelling of Chemicals (GHS) (those with a CLP classification of H350) ; C5 Criterion 5: Pesticide active ingredients listed by the Stockholm Convention in its Annexes A and B, and those meeting all the criteria in paragraph 1 of Annex D of the Convention (those identified as Persistent Organic Pollutants (POPs) in annexes A or B of the Stockholm Convention) ; C6 Criterion 6: Pesticide active ingredients listed by the Rotterdam Convention in its Annex III (those subject to PIC (Prior Informed Consent) regulations under the Convention) ]
	Type II	Yes [ R01 Rule 1: Pesticide active ingredients that meet the criteria of classes Ia or Ib of the WHO Recommended Classification of Pesticides by Hazard (or those with a CLP classification of H330) ; R02 Rule 2: Pesticide active ingredients that meet the criteria of carcinogenicity Categories 1A and 1B of the Globally Harmonized System on Classification and Labelling of Chemicals (GHS) (those with a CLP classification of H350) ; R05 Rule 5: Pesticide active ingredients that are confirmed endocrine disruptors according to the World Health Organization (WHO) definition of an endocrine disruptor ; R06 Rule 6: Pesticide active ingredients listed by the Stockholm Convention in its Annexes A and B, and those meeting all the criteria in paragraph 1 of Annex D of the Convention (those identified as Persistent Organic Pollutants (POPs) in annexes A or B of the Stockholm Convention) ; R07 Rule 7: Pesticide active ingredients listed by the Rotterdam Convention in its Annex III (those subject to PIC (Prior Informed Consent) regulations under the Convention) ; R09 Rule 9: Pesticide active ingredients that have demonstrated a high aquatic toxicity (where acute ecotoxicity for fish, invertebrates or algae =< 0.1 mg l⁻¹) ; R12 Rule 12: Pesticide active ingredients that are bioaccumulative (where bio-concentration factor (BCF) > 2000 l kg⁻¹ (if BCF is not available, where Log P >=5)) ]
Other status information		Severe marine pollutant
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 known
Examples of recorded resistance		-
Physical state		Colourless crystals

Can be a metabolite of:

Parent	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
quintozene	Soil	-	-

Commercial

Property	Value
Availability status	Banned in many countries
Introduction & key dates	Circa 1947, introduced
Example manufacturers & suppliers of products using this active now or historically	Bayer CropScience
Example products using this active	Anticarie Bent-cure Granero No Bunt
Formulation and application details	Often used as a seed dressing.
Commercial production	Hexachlorobenzene is commercially produced through the chlorination of benzene. Production starts with the direct chlorination of benzene at around 200 DegC under atmospheric pressure, where chlorine gas reacts with benzene in the presence of a catalyst such as ferrous oxide to facilitate the substitution of hydrogen atoms with chlorine. This process yields hexachlorobenzene as the primary product, although it can also form as a by-product during the manufacture of other chlorinated compounds, such as pentachlorobenzene or certain pesticides like lindane. An alternative route involves the catalytic chlorination of hexachlorocyclohexane (HCH) isomers, which can also produce hexachlorobenzene.
Impact on climate of production and use	-

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)		0.0047	G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 4 = Verified data	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		-	-	-
Melting point (°C)		226	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Boiling point (°C)		325	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		242	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	8.51 X 1003	Calculated	-
	Log P	3.93	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	High
Fat solubility of residues	Solubility	Soluble	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
	Data type	Regulatory data - observed in metabolism and farm animal feeding studies	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
Density (g ml⁻¹)		2.044	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		1.45	G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 4 = Verified data	Low volatility. 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)		1.03 X 1001	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	Moderately 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)	2000	G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source	Very persistent
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	General literature states DT₅₀ range 2.7-7.5 years, highly persistent
Dissipation rate RL₅₀ (days) on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ (days) on and in plant matrix	Value	9.7	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source	-
	Note	Lettuce leaves, n=1
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	Kd (mL g⁻¹)	-	G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source	Non-mobile
	Koc (mL g⁻¹)	50000
	Notes and range	-
Freundlich	Kf (mL g⁻¹)	-	-	-
	Kfoc (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		-2.31	Calculated	Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	5.35 X 10-03	Calculated	-
	Note	Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW
Potential for particle bound transport index		High	Calculated	-
Potential for loss via drain flow		Non-mobile	Calculated	-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk		-	-	-
Bio-concentration factor	BCF (l kg⁻¹)	35000	A3 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 3 = Unverified data of known source (Other literature values Log BCF range 1.6-5.4 (R3); PIC DGD gives BCF range 375-35000)	High potential
	CT₅₀ (days)	Not available		-

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 10000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source 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)		> 575	G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 4 = Verified data Colinus virginianus	Moderate
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)		> 1000	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Eisenia foetida	Low
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)		0.03	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Oncorhynchus mykiss	High
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)		> 0.0048	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Pimephales promelas 32 day	High
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.5	F2 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 2 = Unverified data of unknown source Daphnia magna 24 hr	Moderate
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		> 0.003	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data Daphnia magna	High
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) (EC₅₀)		0.01	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Scenedesmus abundans	Moderate
Algae - Chronic (growth rate, fresh; mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	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)		> 10000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	Low
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		List I	-	-
Exposure Routes	Public	Primary source of exposure is via diet but risk is low as substance is banned
	Occupational	Risk via exhalation
MRLs	European	EU MRL pesticide database
	Great Britain	GB MRL Register
	Notes	-
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-
Mammalian dose elimination route and rate		-	-	-

Health issues

Specific human health issues (hazard-based)		Carcinogen Genotoxic Endocrine disruptor ✓Yes, known to cause a problem 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 ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative ✓Yes, known to cause a problem Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified XNo, known not to cause a problem No data found Respiratory tract irritant Skin irritant Skin sensitiser No data found ✓Yes, known to cause a problem No data found Eye irritant Phototoxicant   XNo, known not to cause a problem No data found
General human health issues		Extremely hazardous IARC Group 2B carcinogen; CLP data - known human carcinogen; US NTP - suspected carcinogen; US EPA - probable human carcinogen Endocrine issues - Severely disruption of thyroid hormone production

Handling issues

Property	Value and interpretation
General	IMDG Transport Hazard Class 6.1
CLP classification 2013	Health: H350, H372 Environment: H400, H410
WHO Classification	Ia (Extremely hazardous)
UN Number	UN2729
Waste disposal & packaging	Packaging Group III (minor danger)
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	hexachlorobenzene
French	hexachlorobenzène
German	Hexachlorbenzol
Danish	hexachlorbenzen
Italian	esaclorobenzene
Spanish	hexaclorobenceno
Greek	-
Polish	heksachlorobenzen
Swedish	-
Hungarian	-
Dutch	hexachloorbenzeen
Norwegian	-

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Record last updated:	27/10/2025
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