(Also known as: benzeneazobenzene; diazobenzene; azobenzide; azobenzol; azodibenzene)
SUMMARY
Azobenzene is an obsolete miticide. It has a low aqueous solubility and is moderately volatile. It tends to be moderately toxic to biodiversity although there are large gaps in data. It is moderately toxic to mammals if ingested and is a recognised irritant.
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 Moderate alert: Drainflow: Slightly mobile
Warning: Significant data are missing
Ecotoxicity High alert: Daphnia chronic ecotoxicity: High
Warning: Significant data are missing
Human health High alert: Carcinogen
GENERAL INFORMATION
Description
A now obsolete insecticide that was formely used to control mites in a range of situations including glasshouses
Example pests controlled
Boll weevils; Aphids; Spidermites
Example applications
Glasshouse ornamentals including roses, flowering plants
Efficacy & activity
-
Availability status
Considered obsolete but may be available in some countries
Introduction & key dates
1945, first reported
UK regulatory status
UK COPR regulatory status
Not approved
Date COPR inclusion expires
Not applicable
UK LERAP status
No UK approval for use as a pesticide
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
Not applicable
EU Candidate for substitution (CfS)
Not applicable
Listed in EU database
No
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
Isomeric existing in the cis- and trans-forms. The two forms are photo-isomeric switching between forms depending on the light.
Acts by inhibiting oxidative phosphorylation, selective action
CAS RN
103-33-3
EC number
203-102-5
CIPAC number
241
US EPA chemical code
007401
PubChem CID
2272
CLP index number
611-001-00-6
Molecular mass
182.22
PIN (Preferred Identification Name)
diphenyldiazene
IUPAC name
azobenzene
CAS name
diphenyldiazene
Other status information
PAN Bad Actor Chemical
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 known
Fungicide Resistance Class (FRAC MOA class)
Not applicable
Examples of recorded resistance
Tetranychus urticae
Physical state
Orange crystals
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
Spencer Chemicals
Example products using this active
B25
Carbyne
Formulation and application details
Usually supplied as an emulsifiable concentrate
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
6.4
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
at 25 °C
Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
69
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
476
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Octanol-water partition coefficient at pH 7, 20 °C
P
6.61 X 1003
Calculated
-
Log P
3.82
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
High
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
-
-
-
Dissociation constant pKa) at 25 °C
-2.95
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
-
Very strong acid
Vapour pressure at 20 °C (mPa)
-
-
-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.42
V2 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 2 = Unverified data of unknown source
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)
-
-
-
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
-
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)
-
-
-
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)
-
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Slightly mobile
Koc (mL g⁻¹)
2930
Notes and range
Koc range 1350-4510 mL g⁻¹
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
-
-
-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
Cannot be calculated
-
-
Note
-
Potential for particle bound transport index
-
-
-
Potential for loss via drain flow
-
-
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
10
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Low potential
CT₅₀ (days)
-
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 1000
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 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)
-
-
-
Birds - Short term dietary (LC₅₀/LD₅₀)
-
-
-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
-
-
-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
-
-
-
Soil micro-organisms
-
-
-
Collembola
Acute LC₅₀ (mg kg⁻¹)
-
-
-
Chronic NOEC (mg kg⁻¹)
-
-
-
Non-target plants
-
-
-
-
-
-
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
-
-
-
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)
> 0.5
F3 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 ) 3 = Unverified data of known source
Oryzias latipes
Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
-
-
-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
F3 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 ) 3 = Unverified data of known source
Consumer exposure should be low or non-existent since compound is no longer produced or used in most of the developed world
Occupational
Occupational exposure should be low or non-existent since compound is no longer produced or used in most of the developed world
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
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
;
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
XNo, known not to cause a problem
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
Harmful is swallowed or inhaled Tumorigenic agent IARC Group 3 carcinogen - not classifiable; CLP data - known carcinogen; US EPA probable human carcinogen Probably liver toxicant
Handling issues
Property
Value and interpretation
General
IMDG Transport Hazard Class 9 Not compatible with strong oxidising agents
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
Environmental fate
Warning:
Ecotoxicity
