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EC number: 203-137-6 | CAS number: 103-71-9
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
- Endpoint:
- activated sludge nitrification inhibition testing
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Justification for type of information:
- According to handbook data, isocyanates react rapidly with water forming aminic structures as well as carbamic acids, which are mostly unstable, and ureas under release of carbon dioxide. Monitoring the amine formation in hydrolysis studies gives a picture of the degradation of the isocyanate. This behaviour of isocyanates has been used in studies to determine the rate of degradation*. In Guidance on IR & CSA Chapter R.6 it is mentioned that degradation products instead of parent substance can be investigated for ecotoxicological effects if the hydrolysis is very rapidly (t1/2 <1 h), OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000) and Guidance on IR & CSA Chapter R.7b state the same. As phenyl isocyanate hydrolyses to aniline this is the ecotoxicological relevant species. Concluding, tests performed using the corresponding amine can equally be used to assess the ecotoxicological hazards of phenyl isocyanate. An underestimation of environmental hazards is thus avoided supporting a conservative and thus protective hazard assessment.
* Bayer Industry Services (2004), 4-chlorophenyl-isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300181. Leverkusen, Germany.
Bayer Industry Services (2003), Isopropyl isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300095. Leverkusen, Germany. - Reason / purpose for cross-reference:
- read-across source
- Duration:
- 2 h
- Dose descriptor:
- EC50
- Effect conc.:
- 7 mg/L
- Nominal / measured:
- nominal
- Conc. based on:
- test mat.
- Basis for effect:
- inhibition of nitrification rate
- Duration:
- 2 h
- Dose descriptor:
- NOEC
- Effect conc.:
- 2 mg/L
- Nominal / measured:
- nominal
- Conc. based on:
- test mat.
- Basis for effect:
- inhibition of nitrification rate
- Conclusions:
- The toxicity of aniline to microorganisms was tested according to ISO DIS 9509 (Method for Assessing the Inhibition of Nitrification of Activated Sludge Microorganisms by Chemicals and Waste Waters). After 2 hours an EC50 of 7mg/L and a NOEC of 2 mg/L were calculated.
- Executive summary:
The toxicity of aniline to microorganisms was tested according to ISO DIS 9509 (Method for Assessing the Inhibition of Nitrification of Activated Sludge Microorganisms by Chemicals and Waste Waters). After 2 hours an EC50 of 7mg/L and a NOEC of 2 mg/L were calculated.
According to handbook data, isocyanates react rapidly with water forming aminic structures as well as carbamic acids, which are mostly unstable, and ureas under release of carbon dioxide. Monitoring the amine formation in hydrolysis studies gives a picture of the degradation of the isocyanate. This behaviour of isocyanates has been used in studies to determine the rate of degradation*. In Guidance on IR & CSA Chapter R.6 it is mentioned that degradation products instead of parent substance can be investigated for ecotoxicological effects if the hydrolysis is very rapidly (t1/2 <1 h), OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000) and Guidance on IR & CSA Chapter R.7b state the same. As phenyl isocyanate hydrolyses to aniline this is the ecotoxicological relevant species. Concluding, tests performed using the corresponding amine can equally be used to assess the ecotoxicological hazards of phenyl isocyanate. An underestimation of environmental hazards is thus avoided supporting a conservative and thus protective hazard assessment.
* Bayer Industry Services (2004), 4-chlorophenyl-isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300181. Leverkusen, Germany.
Bayer Industry Services (2003), Isopropyl isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300095. Leverkusen, Germany.
- Endpoint:
- activated sludge nitrification inhibition testing
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Study period:
- 2000
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- guideline study with acceptable restrictions
- Justification for type of information:
- According to handbook data, isocyanates react rapidly with water forming aminic structures as well as carbamic acids, which are mostly unstable, and ureas under release of carbon dioxide. Monitoring the amine formation in hydrolysis studies gives a picture of the degradation of the isocyanate. This behaviour of isocyanates has been used in studies to determine the rate of degradation*. In Guidance on IR & CSA Chapter R.6 it is mentioned that degradation products instead of parent substance can be investigated for ecotoxicological effects if the hydrolysis is very rapidly (t1/2 <1 h), OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000) and Guidance on IR & CSA Chapter R.7b state the same. As phenyl isocyanate hydrolyses to aniline this is the ecotoxicological relevant species. Concluding, tests performed using the corresponding amine can equally be used to assess the ecotoxicological hazards of phenyl isocyanate. An underestimation of environmental hazards is thus avoided supporting a conservative and thus protective hazard assessment.
* Bayer Industry Services (2004), 4-chlorophenyl-isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300181. Leverkusen, Germany.
Bayer Industry Services (2003), Isopropyl isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300095. Leverkusen, Germany. - Reason / purpose for cross-reference:
- read-across: supporting information
- Qualifier:
- according to guideline
- Guideline:
- ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms)
- Deviations:
- yes
- Remarks:
- activated sludge of wwtp treating industrial sewage, inoculum with lower nitrification rate (0.5 mg/g/h) and incubation time: 2 h
- GLP compliance:
- not specified
- Analytical monitoring:
- no
- Vehicle:
- no
- Test organisms (species):
- activated sludge, industrial
- Details on inoculum:
- - Type: mixed population of aquatic microorganisms
- Origin: aeration tank of sewage treatment plant Uerdingen of the Bayer AG
- Pretreatment: sludge was washed one time - Test type:
- static
- Water media type:
- freshwater
- Limit test:
- no
- Total exposure duration:
- 2 h
- Test temperature:
- 22+/-1 °C
- Nominal and measured concentrations:
- 0, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 and 32.0 mg/L
- Details on test conditions:
- - test concentration of activated sludge: 3 g/L ss
- specific nitrification rate: 0.5 mg/g/h (inoculum with lower nitrification rate than specified in guideline; nevertheless the inhibition of nitrification could be determined.)
- incubation time: 2 h (deviation from guideline) - Reference substance (positive control):
- yes
- Remarks:
- allylthiourea (11.6 g/L)
- Duration:
- 2 h
- Dose descriptor:
- EC50
- Effect conc.:
- 7 mg/L
- Nominal / measured:
- nominal
- Conc. based on:
- test mat.
- Basis for effect:
- inhibition of nitrification rate
- Duration:
- 2 h
- Dose descriptor:
- NOEC
- Effect conc.:
- 2 mg/L
- Nominal / measured:
- nominal
- Conc. based on:
- test mat.
- Basis for effect:
- inhibition of nitrification rate
- Validity criteria fulfilled:
- not specified
- Conclusions:
- The toxicity of aniline to microorganisms was tested according to ISO DIS 9509 (Method for Assessing the Inhibition of Nitrification of Activated Sludge Microorganisms by Chemicals and Waste Waters). After 2 hours an EC50 of 7 mg/L and a NOEC of 2 mg/L were calculated.
- Executive summary:
The toxicity of aniline to microorganisms was tested according to ISO DIS 9509 (Method for Assessing the Inhibition of Nitrification of Activated Sludge Microorganisms by Chemicals and Waste Waters). After 2 hours an EC50 of 7 mg/L and a NOEC of 2 mg/L were calculated.
According to handbook data, isocyanates react rapidly with water forming aminic structures as well as carbamic acids, which are mostly unstable, and ureas under release of carbon dioxide. Monitoring the amine formation in hydrolysis studies gives a picture of the degradation of the isocyanate. This behaviour of isocyanates has been used in studies to determine the rate of degradation*. In Guidance on IR & CSA Chapter R.6 it is mentioned that degradation products instead of parent substance can be investigated for ecotoxicological effects if the hydrolysis is very rapidly (t1/2 <1 h), OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000) and Guidance on IR & CSA Chapter R.7b state the same. As phenyl isocyanate hydrolyses to aniline this is the ecotoxicological relevant species. Concluding, tests performed using the corresponding amine can equally be used to assess the ecotoxicological hazards of phenyl isocyanate. An underestimation of environmental hazards is thus avoided supporting a conservative and thus protective hazard assessment.
* Bayer Industry Services (2004), 4-chlorophenyl-isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300181. Leverkusen, Germany.
Bayer Industry Services (2003), Isopropyl isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300095. Leverkusen, Germany.
Referenceopen allclose all
test concentration nitrate and nitrite inhibition
produced (mg/L) (%)
blank 3.05
ref. inhib. < 1.0 100
aniline (mg/L):
0.5 3.05 0
1.0 3.15 0
2.0 3.05 0
4.0 2.65 16
8.0 1.75 52
16.0 < 1.0 100
32.0 < 1.0 100
quantification limit of nitrate-N and nitrite-N: 1 mg/L
half of the quantification limit was used for calculation of
% inhibition.
test concentration nitrate and nitrite inhibition
produced (mg/L) (%)
blank 3.05
ref. inhib. < 1.0 100
aniline (mg/L):
0.5 3.05 0
1.0 3.15 0
2.0 3.05 0
4.0 2.65 16
8.0 1.75 52
16.0 < 1.0 100
32.0 < 1.0 100
quantification limit of nitrate-N and nitrite-N: 1 mg/L
half of the quantification limit was used for calculation of
% inhibition.
Description of key information
Due to the rapid hydrolysis of phenyl isocyanate, results from the
hydrolysis product aniline are also taken into account for assessment.
In order to protect the efficiency of domestic and industrial waste
water treatment plants, inhibition of nitrification by the hydrolysis
product aniline is identified to be the most sensitive test system.
Nitrification inhibition was measured on activated sludge determined
according to ISO DIS 9509 (Method for Assessing the Inhibition of
Nitrification of Activated Sludge Microorganisms by Chemicals and Waste
Waters). An EC50 of 7 mg/l and and a NOEC of 2 mg/L was determined after
2 hours incubation.
Key value for chemical safety assessment
- EC50 for microorganisms:
- 7 mg/L
- EC10 or NOEC for microorganisms:
- 2 mg/L
Additional information
The toxicity to microorganisms of phenyl isocyanate was tested according to OECD Guideline 209 "Activated Sludge, Respiration Inhibition Test". During 3 hours an EC10 of 309 mg/L and an EC50 of 702 mg/L was measured. Due to the rapid hydrolysis of phenyl isocyanate, results from the hydrolysis product aniline are also taken into account for assessment, based on the justification for read-across:
According to handbook data, isocyanates react rapidly with water forming aminic structures as well as carbamic acids, which are mostly unstable, and ureas under release of carbon dioxide. Monitoring the amine formation in hydrolysis studies gives a picture of the degradation of the isocyanate. This behaviour of isocyanates has been used in studies to determine the rate of degradation*. In Guidance on IR & CSA Chapter R.6 it is mentioned that degradation products instead of parent substance can be investigated for ecotoxicological effects if the hydrolysis is very rapidly (t1/2 <1 h), OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000) and Guidance on IR & CSA Chapter R.7b state the same. As phenyl isocyanate hydrolyses to aniline this is the ecotoxicological relevant species. Concluding, tests performed using the corresponding amine can equally be used to assess the ecotoxicological hazards of phenyl isocyanate. An underestimation of environmental hazards is thus avoided supporting a conservative and thus protective hazard assessment.
* Bayer Industry Services (2004), 4-chlorophenyl-isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300181. Leverkusen, Germany.
Bayer Industry Services (2003), Isopropyl isocyanate: Investigation on Stability in Aqueous Test Solutions. Project No: 200300095. Leverkusen, Germany.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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