Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 266-096-3 | CAS number: 66063-05-6
Biodegradation in water and sediment: simulation tests
Administrative data
Link to relevant study record(s)
- Endpoint:
- biodegradation in water: simulation testing on ultimate degradation in surface water
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 1986-03-10. Revision: 2001-06-08
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- test procedure in accordance with national standard methods with acceptable restrictions
- Qualifier:
- no guideline available
- Principles of method if other than guideline:
- Weight of Evidence based on mineralisation observed in water/sediment study
- GLP compliance:
- no
- Remarks:
- Carried out prior to GLP
- Radiolabelling:
- yes
- Remarks:
- Specific radioactivity:1287.6 kBq/mg
- Oxygen conditions:
- aerobic
- Inoculum or test system:
- natural water / sediment
- Details on inoculum:
- Two sediments and associated waters were freshly collected from the field. The characterisation of the water sediment systems is given in Table 1.
The water was filtered through a large folded filter and the sediment was sieved through a 2 mm sieve, followed by dry weight determination. A number of 16 incubation vessels were prepared; 8 for each water-sediment system. Prior to dosing, there was an acclimatisation period of 14 days. Although it is assumed that the conditions during the acclimatisation period were the same as during the incubation, this is not confirmed in the report. - Duration of test (contact time):
- 91 d
- Initial conc.:
- 0.4 mg/L
- Based on:
- act. ingr.
- Parameter followed for biodegradation estimation:
- radiochem. meas.
- Details on study design:
- System for determination of degradation:
The exact size of the incubation vessels is not given. Each vessel had three openings on top. Two of them were used for O2 measurements of the water phase and driving out CO2 via a special device. To the other opening, a volatile trap was connected, filled with soda lime and closed with an oil-coated quartz wool plug. The volatile traps were designed to absorb 14CO2 and volatile organic compounds and were permeable for oxygen. There were also two openings on the side. One in the headspace, closed with a septum, could be used for gas determination and one below the water surface, closed with a tap, could be used to decant water.
Processing of water:
A portion of the water (50 mL) was transferred to a fresh test vessel. The system was closed and 3 mL concentrated hydrochloric acid was injected through the septum onto the water (pH = 1) and stirred for 2 hours with a magnetic stirrer. After sweeping out volatile compounds from the vessel into the trap (using compressed air), 1 mL of acetic acid was added to the entire batch (except for the last sampling time). According to the authors this was done to liberate carbon dioxide.
Extraction:
The remaining water was centrifuged and then filtered through a < 0.2 µm membrane filter (filter II) after first passing through an initial filter (filter I). The centrifugate was processed together with the sediment. After filtration, the water was extracted three times with ethyl acetate. The organic phases were combined and evaporated to dryness on a rotary evaporator. Then they were dissolved in methanol and analysed by TLC. The extracted aqueous phase was freeze-dried and dissolved in methanol and analysed by TLC. Solids that were not soluble in methanol were combusted after centrifugation to determine the radioactivity.
Processing of sediment:
The aqueous sediment was extracted 3 times with ethanol and once with ethyl acetate. Each extract was centrifuged and decanted through a folded filter (filter III). The filtered solutions were combined, evaporated to dryness at 40ºC, dissolved in methanol and analysed by TLC. Solids that were not soluble in methanol were combusted after centrifugation for determination of radioactivity.
To determine the amount of carbonate in the sediment, a portion of sediment was placed in a fresh test vessel (as described above) and distilled water was added; the system was closed and concentrated hydrochloric acid was injected through the septum onto the water (pH = 1) and stirred for 2 hours with a magnetic stirrer. Then volatile compounds were swept out of the test vessel into the trap by compressed air.
Radioactivity measurements:
The amount of radioactivity was determined before and after each processing step. The oil-coated quartz wool plug were extracted with ethyl acetate. A part of the extract was used for measuring radioactivity. 14CO2 was liberated from the soda lime of the trap by the treatment with a HCl solution in a suitable apparatus. Liberated CO2 was swept into a beta-phenylethylamine/butyl-PBD cocktail by a stream of nitrogen. The cocktail was subsequently measured. Liquid samples were measured by LSC. Sub-samples of air-dried and ground sediment were combusted in an oxidizer to determine the radioactivity. Filter was combusted to determine the radioactivity. Filter II was extracted with methanol and the radioactivity in the methanol was determined. Filter III was dissolved in ethyl acetate and the radioactivity was determined by LSC. - Compartment:
- entire system
- % Non extractable:
- 13.35
- % CO2:
- 1.55
- % Recovery:
- 106.35
- Remarks on result:
- other: Day 14 Lienden total system
- Compartment:
- entire system
- % Non extractable:
- 18.8
- % CO2:
- 5.35
- % Recovery:
- 104.65
- Remarks on result:
- other: Day 30 Lienden total system
- Compartment:
- entire system
- % Non extractable:
- 20.45
- % CO2:
- 12.9
- % Recovery:
- 102.2
- Remarks on result:
- other: Day 63 Lienden total system
- Compartment:
- entire system
- % Non extractable:
- 23.85
- % CO2:
- 21.7
- % Recovery:
- 96.7
- Remarks on result:
- other: Day 91 Lienden total system
- Compartment:
- entire system
- % Non extractable:
- 11.55
- % CO2:
- 0.85
- % Recovery:
- 102.15
- Remarks on result:
- other: Day 14 IJzendoorn total system
- Compartment:
- entire system
- % Non extractable:
- 15.05
- % CO2:
- 2.2
- % Recovery:
- 109.55
- Remarks on result:
- other: Day 30 IJzendoorn total system
- Compartment:
- entire system
- % Non extractable:
- 17.5
- % CO2:
- 5.2
- % Recovery:
- 105.45
- Remarks on result:
- other: Day 63 IJzendoorn total system
- Compartment:
- entire system
- % Non extractable:
- 29.45
- % CO2:
- 11.5
- % Recovery:
- 105.6
- Remarks on result:
- other: Day 91 IJzendoorn total system
- Remarks on result:
- other: Not specified
- Transformation products:
- not measured
- Remarks:
- See details on results
- Details on results:
- In Table 2 and Table 3, the distribution of recovered radioactivity is given for the IJzendoorn and the Lienden system, respectively. In the IJzendoorn system, the total recovery of the radioactivity varied between 102% and 110%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (91.1% a.r.) was recovered in the sediment (61.65% extractable and 29.45% un-extractable). In the Lienden system, the total recovery of the radioactivity varied between 96.7% and 106%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (60.0% a.r.) was recovered in the sediment (36.15% extractable and 23.85% unextractable).
TRANSFORMATION PRODUCTS
Three minor metabolites were identified in the water and sediment phases of both systems: Metabolite III (N-[(4-chlorophenyl)methyl]-N-cyclopentylurea = M03), Metabolite IV (N-cyclopentyl- N’-phenylurea = M04) and metabolite XVI (N-[(4-chlorophenyl)methyl]-N-cyclopentylamine = M16). The latter metabolite was not found in a separate study, because they used the [carbonyl-14C]Pencycuron label. The distribution of the radioactivity as extracted from water and sediment and the total system is presented in Table 4 - 6, for the IJzendoorn system and in Table 7 – 9 for the Lienden system. - The study was not conducted according a specific guideline and not in compliance with GLP (the latter was introduced just a couple of years before the study was carried out).
- No measurements of the redox potential in the sediment were conducted during this study. No experimental evidence is available that the sediment was aerobic at the surface and anaerobic below the surface (as required by OECD 208 to simulate an aerobic test system simulating natural surface water). However, the water was aerobic during incubation, and the water was gently stirred without disturbance of the sediment, which could be adequate conditions to create the required gradient in the sediment (aerobic at the surface and anaerobic below the surface).
- It should be noted though, that the sediment layer was only about 1.3 cm thick (OECD 308 requires 2.5±0.5 cm).
- Overall conclusion: the study is acceptable.
- Validity criteria fulfilled:
- yes
- Remarks:
- Minor deviations: The study was carried out prior to GLP The redox potential in sediment was not measured. No day 0 measurements were made. The sediment layer was only about 1.3 cm thick (OECD 308 requires 2.5±0.5 cm) Study is considered to be acceptable.
- Conclusions:
- In the Ijzendoorn system, the total recovery of the radioactivity varied between 102% and 110%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (91.1% a.r.) was recovered in the sediment (61.65% extractable and 29.45% un-extractable). In the Lienden system, the total recovery of the radioactivity varied between 96.7% and 106%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (60.0% a.r.) was recovered in the sediment (36.15% extractable and 23.85% unextractable).
Three minor metabolites were identified in the water and sediment phases of both systems: Metabolite III (N-[(4-chlorophenyl)methyl]-N-cyclopentylurea = M03), Metabolite IV (N-cyclopentyl-N-phenylurea = M04) and metabolite XVI (N-[(4-chlorophenyl)methyl]-N-cyclopentylamine = M16).
Modelling parameters were derived in a separate study from Hammel&Kahl (2009) following FOCUS guidelines and recalculated in the DAR. - Executive summary:
Radiolabelled [Cyclopentyl-3,5-14C]Pencycuron and [Cyclopentyl-3,5-14C]Pencycuron were applied to two water/sediment systems collected from the Netherlands at a rate of 0.4 mg/L. Incubation over 91 days at 22 ± 0.5 ºC in the dark was carried out and samples were taken on 14, 30, 63 and 91 days.
The system Lienden (with a higher amount of sand) degraded the compound about twice as rapidly as the system Uzendoorn.After 91 days of incubation, 11.5% and 21.7% of the appliedradioactivity was degraded to 14CO2 in the Uzendoorn and Liendentest systems, respectively. The percentage of extracted PENCYCURON was 55% and 39%, respectively. Three metaboliteswere identified by thin layer chromatography (TLC):N-cyclopentyl-N'-phenylurea, N-[(4-chlorophenyl)methyl]-N-cyclo=pentylurea and N-[(4-chlorophenyl)methyl]-N-cyclopentylamine.- Endpoint:
- biodegradation in water: sediment simulation testing
- Type of information:
- calculation (if not (Q)SAR)
- Adequacy of study:
- key study
- Study period:
- 2009-03-19
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- guideline study with acceptable restrictions
- Reason / purpose for cross-reference:
- reference to other study
- Qualifier:
- according to guideline
- Guideline:
- other: FOCUS (2005) - Reference Sanco/10058/2005
- GLP compliance:
- no
- Remarks:
- This is a kinetic evaluation
- Oxygen conditions:
- aerobic
- Details on study design:
- A modelling study was undertaken using the results of the water-sediment study with pencycuron, summarised in Scholz & Freymiller (1986), in order to derive level I modelling DT50 and DT90 values for pencycuron and pencycuron-PB-amine, and level II modelling DT50 values for pencycuron, according to the guidance in FOCUS (2005: SANCO/1058/2005 version 1.0).
The kinetic evaluation was performed according to FOCUS [2005]. Generally, singlephase evaluations can be separated from multiple-phase evaluations. Single phase evaluations are denoted as Level I evaluations and apply to degradation in the total system and dissipation in either the water- or the sediment phase. Multi-phase evaluations, denoted as Level II evaluation, acknowledge the co-existence of water and sediment phase and include a reversible transfer of the compound between the phases. Because this transfer is explicitly included, the estimated endpoint represents degradation (not dissipation) for both phases.
A Level I evaluation was performed for the total system (degradation), and the single phases (dissipation) considering the parent and the metabolite. A Level II evaluation was performed for the parent.
In general, residue data were used as reported in Scholz and Freymiller [2001]. Since no time zero samples were taken, the value for the metabolite in water and sediment was set to 0 [FOCUS, 2005], because only the parent was applied to the system.
Identification of Appropriate Kinetic Model:
The choice of the appropriate kinetic model was based on visual inspection of the fit and the scaled Chi^2-error. The Level II model further had to pass the FSed-test. It is checked by the T-test whether degradation or dissipation parameters are sufficiently reliable to be used for exposure modelling. - Key result
- Compartment:
- natural water / sediment
- DT50:
- 139 d
- Type:
- other: SFO
- Temp.:
- 22 °C
- Remarks on result:
- other: Total system - IJzendoorn
- Key result
- Compartment:
- natural water / sediment
- DT50:
- 353 d
- Type:
- other: SFO
- Temp.:
- 12 °C
- Remarks on result:
- other: Total system - IJzendoorn (calculated from 22°C)
- Key result
- Compartment:
- natural water / sediment
- DT50:
- 82.6 d
- Type:
- other: SFO
- Temp.:
- 22 °C
- Remarks on result:
- other: Total system - Lienden
- Key result
- Compartment:
- natural water / sediment
- DT50:
- 210.3 d
- Type:
- other: SFO
- Temp.:
- 12 °C
- Remarks on result:
- other: Total system - Lienden (calculated from 22°C)
- Key result
- Compartment:
- water
- DT50:
- 0.11 d
- Type:
- other: FOMC
- Temp.:
- 22 °C
- Remarks on result:
- other: Dissipation - IJzendoorn
- Key result
- Compartment:
- water
- DT50:
- 0.28 d
- Type:
- other: FOMC
- Temp.:
- 12 °C
- Remarks on result:
- other: Dissipation - IJzendoorn (calculated from 22°C)
- Key result
- Compartment:
- water
- DT50:
- 3.8 d
- Type:
- other: FOMC
- Temp.:
- 22 °C
- Remarks on result:
- other: Dissipation - Lienden
- Key result
- Compartment:
- water
- DT50:
- 9.7 d
- Type:
- other: FOMC
- Temp.:
- 12 °C
- Remarks on result:
- other: Dissipation - Lienden (calculated from 22°C)
- Transformation products:
- not measured
- Details on results:
- For the parent the SFO fits were visually and statistically well acceptable. Thus biphasic models were not tested. For the metabolite, Chi2-errors reached about 16 %. In these cases the overall level of values is low (mostly below 10 % AR) and the scatter is high which both leads to a high Chi^2-error.
For the IJzendoorn data set the concentrations of Pencycuron-PB-Amine are underestimated at the beginning and overestimated at the end of the experiment. The underestimation is due to the estimation of the initial parent mass of only 91 %, which led to a reduced metabolite formation. This in total produced a conservative dissipation rate for Pencycuron-PB-Amine. The low estimated initial mass of the parent led also to a conservative dissipation rate of Pencycuron. For the Lienden data set the Chi2-error value is below 15 % and the overall trend of the data is fitted well for Pencycuron and Pencycuron-PB-Amine.
PENCYCURON, LEVEL P-I, WHOLE SYSTEM:
SFO was applied to the day 14-91 replicate whole system data with M0 free. This gave an acceptable SFO fit through the measured data. The day 0 value for pencycuron was underestimated (91% AR for IJzendoorn and 88% AR for Lienden), but this reflects a conservative estimation of the SFO degradation rate. FOMC was not run by the authors of the report, as this was not meaningful without a day 0 value. As a check, fitting of the whole system study data to SFO and FOMC with inclusion of a presumed day 0 value of 100% AR was performed by the RMS (M0 free). For both systems, SFO gave an acceptable fit, which was not improved by FOMC fitting. Moreover, the degradation rates determined by fitting with inclusion of the assumed day 0 values of 100% AR were slightly higher than the reported values, and the latter are therefore preferred in a worst case approach.
PENCYCURON, LEVEL P-I, WATER
In the absence of day 0 samples, and considering the fast dissipation of the parent in the water, the initial amount of pencuycuron in the water was fixed to 100% during the fitting. The SFO model did not give an acceptable fit (for IJzendoorn and Lienden respectively, X^2 (err) value 48% and 38%; systematic underestimation of concentrations at later time points). Therefore FOMC was also fitted to the data, and this model gave a statistically and visually acceptable fit. Other models (HS, DFOP) were not run since the 10% of the initial amount was reached within the study period. The accuracy of the DT50 values is not certain, since the initial amount of pencycuron was fixed to 100%, and the dissipation was extremely rapid, with >95% or about 75% dissipation having occurred at the first sampling. However, the endpoints are only used for comparison with trigger values. Since the order of magnitude of the DT50 is acceptable, and the highest DT50 (water) is well above the trigger value of 2 days, mentioned in the Guidance Document on Aquatic Ecotoxicology (SANCO/3268/2001 rev.4 of 17 October 2002, the estimates are accepted.
The water-sediment study was performed at 22°C. The normalisation of the test results to 20°C was performed by the RMS and took into consideration the Q10 factor of 2.58 recommended by EFSA (2007: EFSA Journal (2007) 622, 1-32). - Validity criteria fulfilled:
- yes
- Conclusions:
- Pencycuron, 20°C: level I DT50 values 99.1 and 166.7 days (whole system), 0.13 and 4.6 days (water)
- Executive summary:
A modelling study was undertaken using the results of the water-sediment study with pencycuron, in order to derive level I modelling DT50 and DT90 values for pencycuron, according to the guidance in FOCUS (2005: SANCO/1058/2005 version 1.0).
- Endpoint:
- biodegradation in water: sediment simulation testing
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1986-03-10. Revision: 2001-06-08
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- test procedure in accordance with national standard methods with acceptable restrictions
- Qualifier:
- no guideline available
- Principles of method if other than guideline:
- See Detail on study design and Details on inoculum.
- GLP compliance:
- no
- Remarks:
- Carried out prior to GLP
- Radiolabelling:
- yes
- Remarks:
- Specific radioactivity:1287.6 kBq/mg
- Oxygen conditions:
- aerobic
- Inoculum or test system:
- natural water / sediment
- Details on inoculum:
- Two sediments and associated waters were freshly collected from the field. The characterisation of the water sediment systems is given in Table 1.
The water was filtered through a large folded filter and the sediment was sieved through a 2 mm sieve, followed by dry weight determination. A number of 16 incubation vessels were prepared; 8 for each water-sediment system. Prior to dosing, there was an acclimatisation period of 14 days. Although it is assumed that the conditions during the acclimatisation period were the same as during the incubation, this is not confirmed in the report. - Duration of test (contact time):
- 91 d
- Initial conc.:
- 0.4 mg/L
- Based on:
- act. ingr.
- Parameter followed for biodegradation estimation:
- radiochem. meas.
- Details on study design:
- System for determination of degradation:
The exact size of the incubation vessels is not given. Each vessel had three openings on top. Two of them were used for O2 measurements of the water phase and driving out CO2 via a special device. To the other opening, a volatile trap was connected, filled with soda lime and closed with an oil-coated quartz wool plug. The volatile traps were designed to absorb 14CO2 and volatile organic compounds and were permeable for oxygen. There were also two openings on the side. One in the headspace, closed with a septum, could be used for gas determination and one below the water surface, closed with a tap, could be used to decant water.
Processing of water:
A portion of the water (50 mL) was transferred to a fresh test vessel. The system was closed and 3 mL concentrated hydrochloric acid was injected through the septum onto the water (pH = 1) and stirred for 2 hours with a magnetic stirrer. After sweeping out volatile compounds from the vessel into the trap (using compressed air), 1 mL of acetic acid was added to the entire batch (except for the last sampling time). According to the authors this was done to liberate carbon dioxide.
Extraction:
The remaining water was centrifuged and then filtered through a < 0.2 µm membrane filter (filter II) after first passing through an initial filter (filter I). The centrifugate was processed together with the sediment. After filtration, the water was extracted three times with ethyl acetate. The organic phases were combined and evaporated to dryness on a rotary evaporator. Then they were dissolved in methanol and analysed by TLC. The extracted aqueous phase was freeze-dried and dissolved in methanol and analysed by TLC. Solids that were not soluble in methanol were combusted after centrifugation to determine the radioactivity.
Processing of sediment:
The aqueous sediment was extracted 3 times with ethanol and once with ethyl acetate. Each extract was centrifuged and decanted through a folded filter (filter III). The filtered solutions were combined, evaporated to dryness at 40ºC, dissolved in methanol and analysed by TLC. Solids that were not soluble in methanol were combusted after centrifugation for determination of radioactivity.
To determine the amount of carbonate in the sediment, a portion of sediment was placed in a fresh test vessel (as described above) and distilled water was added; the system was closed and concentrated hydrochloric acid was injected through the septum onto the water (pH = 1) and stirred for 2 hours with a magnetic stirrer. Then volatile compounds were swept out of the test vessel into the trap by compressed air.
Radioactivity measurements:
The amount of radioactivity was determined before and after each processing step. The oil-coated quartz wool plug were extracted with ethyl acetate. A part of the extract was used for measuring radioactivity. 14CO2 was liberated from the soda lime of the trap by the treatment with a HCl solution in a suitable apparatus. Liberated CO2 was swept into a beta-phenylethylamine/butyl-PBD cocktail by a stream of nitrogen. The cocktail was subsequently measured. Liquid samples were measured by LSC. Sub-samples of air-dried and ground sediment were combusted in an oxidizer to determine the radioactivity. Filter was combusted to determine the radioactivity. Filter II was extracted with methanol and the radioactivity in the methanol was determined. Filter III was dissolved in ethyl acetate and the radioactivity was determined by LSC. - Compartment:
- natural water / sediment: freshwater
- Remarks on result:
- other: The calculation of the original study is not correct. The correct DT50 is in XXX.
- Transformation products:
- yes
- No.:
- #3
- No.:
- #4
- No.:
- #16
- Details on transformation products:
- -Formation of each transformation product during test: Three minor metabolites were identified in the water and sediment phases of both systems: Metabolite III (N-[(4-chlorophenyl)methyl]-N-cyclopentylurea = M03), Metabolite IV (N-cyclopentyl- N’-phenylurea = M04) and metabolite XVI (N-[(4-chlorophenyl)methyl]-N-cyclopentylamine = M16). The latter metabolite was not found in a separate study, because they used the [carbonyl-14C]Pencycuron label. The distribution of the radioactivity as extracted from water and sediment and the total system is presented in Table 4 - 6, for the IJzendoorn system and in Table 7 – 9 for the Lienden system.
- Details on results:
- In Table 2 and Table 3, the distribution of recovered radioactivity is given for the IJzendoorn and the Lienden system, respectively. In the IJzendoorn system, the total recovery of the radioactivity varied between 102% and 110%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (91.1% a.r.) was recovered in the sediment (61.65% extractable and 29.45% un-extractable). In the Lienden system, the total recovery of the radioactivity varied between 96.7% and 106%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (60.0% a.r.) was recovered in the sediment (36.15% extractable and 23.85% unextractable).
- The study was not conducted according a specific guideline and not in compliance with GLP (the latter was introduced just a couple of years before the study was carried out).
- No measurements of the redox potential in the sediment were conducted during this study. No experimental evidence is available that the sediment was aerobic at the surface and anaerobic below the surface (as required by OECD 208 to simulate an aerobic test system simulating natural surface water). However, the water was aerobic during incubation, and the water was gently stirred without disturbance of the sediment, which could be adequate conditions to create the required gradient in the sediment (aerobic at the surface and anaerobic below the surface).
- It should be noted though, that the sediment layer was only about 1.3 cm thick (OECD 308 requires 2.5±0.5 cm).
- Overall conclusion: the study is acceptable.
- Validity criteria fulfilled:
- yes
- Remarks:
- Minor deviations: The study was carried out prior to GLP The redox potential in sediment was not measured. No day 0 measurements were made. The sediment layer was only about 1.3 cm thick (OECD 308 requires 2.5±0.5 cm) Study is considered to be acceptable.
- Conclusions:
- In the IJzendoorn system, the total recovery of the radioactivity varied between 102% and 110%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (91.1% a.r.) was recovered in the sediment (61.65% extractable and 29.45% un-extractable). In the Lienden system, the total recovery of the radioactivity varied between 96.7% and 106%. At the end of the incubation (after 91 days), the major part of the applied radioactivity (60.0% a.r.) was recovered in the sediment (36.15% extractable and 23.85% unextractable).
Three minor metabolites were identified in the water and sediment phases of both systems: Metabolite III (N-[(4-chlorophenyl)methyl]-N-cyclopentylurea = M03), Metabolite IV (N-cyclopentyl-N-phenylurea = M04) and metabolite XVI (N-[(4-chlorophenyl)methyl]-N-cyclopentylamine = M16).
Modelling parameters were derived in a separate study M-0344097-01-1 following FOCUS guidelines and recalculated in the DAR. - Executive summary:
Radiolabelled [Cyclopentyl-3,5-14C]Pencycuron and [Cyclopentyl-3,5-14C]Pencycuron were applied to two water/sediment systems collected from the Netherlands at a rate of 0.4 mg/L. Incubation over 91 days at 22 ± 0.5 ºC in the dark was carried out and samples were taken on 14, 30, 63 and 91 days.
The system Lienden (with a higher amount of sand) degraded the compound about twice as rapidly as the system Uzendoorn.After 91 days of incubation, 11.5% and 21.7% of the appliedradioactivity was degraded to 14CO2 in the Uzendoorn and Liendentest systems, respectively. The percentage of extracted PENCYCURON was 55% and 39%, respectively. Three metaboliteswere identified by thin layer chromatography (TLC):N-cyclopentyl-N'-phenylurea, N-[(4-chlorophenyl)methyl]-N-cyclo=pentylurea and N-[(4-chlorophenyl)methyl]-N-cyclopentylamine.
Referenceopen allclose all
Mineralisation to CO2 measured as 11.5 - 21.7 % AR in the aerobic water sediment study.
Table 2. Distribution of recovered radioactivity (% a.r.) in the IJzendoorn system, mean of duplicate test vessels
Incubation time | (days) | 14 | 30 | 63 | 91 |
Volatiles
Water | soda lime oil-coated quartz wool plug | 0.85 < 0.01 7.20 | 2.20 < 0.01 4.55 | 5.20 < 0.01 5.00 | 11.50 < 0.1 3.05 |
Sediment | extracted | 82.55 | 87.75 | 77.75 | 61.65 |
| sediment after extraction | 6.30 | 11.90 | 15.05 | 26.95 |
| folded filter (III) | 1.75 | 1.25 | 1.20 | 0.95 |
| initial filter (I) | 0.95 | 0.70 | 0.45 | 0.20 |
| membrane filter (II) | 2.55 | 1.20 | 0.80 | 1.35 |
| subtotal not-extractable portion | 11.55 | 15.05 | 17.50 | 29.45 |
Subtotal sediment | 94.10 | 102.80 | 95.25 | 91.10 | |
Total | 102.15 | 109.55 | 105.45 | 105.60 | |
Table 3. Distribution of recovered radioactivity (% a.r.) in the Lienden system, mean of duplicate test vessels
Incubation time | (days) | 14 | 30 | 63 | 91 |
Volatiles | soda lime | 1.55 | 5.35 | 12.9 | 21.70 |
| oil-coated quartz wool plug | < 0.01 | < 0.01 | < 0.01 | < 0.1 |
Water |
| 35.85 | 21.25 | 21.50 | 14.95 |
Sediment | extracted | 56.55 | 59.25 | 47.35 | 36.15 |
| sediment after extraction | 3.75 | 9.25 | 16.35 | 20.00 |
| folded filter (III) | 2.15 | 1.35 | 0.90 | 0.75 |
| initial filter (I) | 2.35 | 2.75 | 1.20 | 0.90 |
| membrane filter (II) | 4.05 | 4.60 | 2.00 | 2.20 |
| subtotal not-extractable portion | 13.35 | 18.80 | 20.45 | 23.85 |
Subtotal sediment | 68.90 | 78.05 | 67.80 | 60.00 | |
Total | 106.35 | 104.65 | 102.20 | 96.70 | |
Table 4. Proportions (% a.r.) of radioactive components in water of the IJzendoorn system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 3.90 | 0.55 | 1.35 | 1.15 | 0.15 | 0.15 | 7.20 |
30 | 2.15 | 0.25 | 0.70 | 1.10 | 0.20 | 0.15 | 4.55 |
63 | 1.95 | 0.45 | 0.45 | 1.25 | 0.80 | 0.10 | 5.00 |
91 | 1.20 | 0.60 | 0.15 | 0.95 | 0.10 | 0.10 | 3.05 |
1 Average of duplicates
Table 5. Proportions (% a.r.) of radioactive components in the sediment extract of the IJzendoorn system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 77.25 | 0.30 | 0.50 | 4.55 | - | - | 82.55 |
30 | 79.10 | 0.50 | 0.50 | 7.15 | - | 0.5 | 87.75 |
63 | 68.45 | 1.00 | 0.65 | 6.85 | 0.70 | 0.10 | 77.75 |
91 | 53.50 | 1.50 | 0.30 | 4.05 | 2.10 | 0.25 | 61.65 |
1 Average of duplicates
Table 6. Proportions (% a.r.) of radioactive components in the total IJzendoorn system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 81.15 | 0.80 | 1.85 | 5.70 | 0.10 | 0.15 | 89.75 |
30 | 81.25 | 0.75 | 1.20 | 8.25 | 0.20 | 0.65 | 92.30 |
63 | 70.40 | 1.45 | 1.10 | 8.10 | 1.50 | 0.20 | 82.75 |
91 | 54.70 | 2.10 | 0.35 | 5.00 | 2.20 | 0.35 | 64.70 |
1 Average of duplicates
Table 7. Proportions (% a.r.) of radioactive components in water of the Lienden system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 24.90 | 2.70 | 4.25 | 2.80 | 0.95 | 0.25 | 35.85 |
30 | 13.80 | 1.35 | 2.50 | 2.70 | 0.50 | 0.40 | 21.25 |
63 | 11.45 | 3.00 | 2.60 | 2.45 | 1.85 | 0.15 | 21.50 |
91 | 5.55 | 4.30 | 0.95 | 3.50 | 0.35 | 0.30 | 14.95 |
1 Average of duplicates
Table 8. Proportions (% a.r.) of radioactive components in the sediment extract of the Lienden system at several time points after application of the test substance (mean of two duplicate vessels1)
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 52.80 | < 0.1 | < 0.10 | 2.80 | 0.95 | - | 56.55 |
30 | 54.65 | 0.50 | < 0.10 | 3.40 | 0.35 | 0.40 | 59.25 |
63 | 43.05 | 1.10 | 0.30 | 2.35 | 0.55 | < 0.10 | 47.35 |
91 | 33.25 | 0.50 | < 0.10 | 2.30 | < 0.10 | < 0.10 | 36.15 |
1 Average of duplicates
Table 9. Proportions (% a.r.) of radioactive components in the total Lienden system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 77.70 | 2.70 | 4.25 | 5.60 | 1.90 | 0.25 | 92.40 |
30 | 68.45 | 1.80 | 2.50 | 6.10 | 0.85 | 0.80 | 80.50 |
63 | 54.50 | 4.10 | 2.90 | 4.80 | 2.40 | 0.15 | 68.85 |
91 | 38.80 | 4.80 | 1.00 | 5.80 | 0.35 | 0.35 | 51.10 |
1 Average of duplicates
A separate modelling study was conducted in 2009, which derived level I modelling DT50 and DT90 values for pencycuron and pencycuron-PB-amine, and level II modelling DT50 values for pencycuron, according to the guidance in FOCUS (2005: SANCO/1058/2005 version 1.0).
Remarks by RMS
Table 2. Distribution of recovered radioactivity (% a.r.) in the IJzendoorn system, mean of duplicate test vessels
Incubation time | (days) | 14 | 30 | 63 | 91 |
Volatiles
Water | soda lime oil-coated quartz wool plug | 0.85 < 0.01 7.20 | 2.20 < 0.01 4.55 | 5.20 < 0.01 5.00 | 11.50 < 0.1 3.05 |
Sediment | extracted | 82.55 | 87.75 | 77.75 | 61.65 |
| sediment after extraction | 6.30 | 11.90 | 15.05 | 26.95 |
| folded filter (III) | 1.75 | 1.25 | 1.20 | 0.95 |
| initial filter (I) | 0.95 | 0.70 | 0.45 | 0.20 |
| membrane filter (II) | 2.55 | 1.20 | 0.80 | 1.35 |
| subtotal not-extractable portion | 11.55 | 15.05 | 17.50 | 29.45 |
Subtotal sediment | 94.10 | 102.80 | 95.25 | 91.10 | |
Total | 102.15 | 109.55 | 105.45 | 105.60 | |
Table 3. Distribution of recovered radioactivity (% a.r.) in the Lienden system, mean of duplicate test vessels
Incubation time | (days) | 14 | 30 | 63 | 91 |
Volatiles | soda lime | 1.55 | 5.35 | 12.9 | 21.70 |
| oil-coated quartz wool plug | < 0.01 | < 0.01 | < 0.01 | < 0.1 |
Water |
| 35.85 | 21.25 | 21.50 | 14.95 |
Sediment | extracted | 56.55 | 59.25 | 47.35 | 36.15 |
| sediment after extraction | 3.75 | 9.25 | 16.35 | 20.00 |
| folded filter (III) | 2.15 | 1.35 | 0.90 | 0.75 |
| initial filter (I) | 2.35 | 2.75 | 1.20 | 0.90 |
| membrane filter (II) | 4.05 | 4.60 | 2.00 | 2.20 |
| subtotal not-extractable portion | 13.35 | 18.80 | 20.45 | 23.85 |
Subtotal sediment | 68.90 | 78.05 | 67.80 | 60.00 | |
Total | 106.35 | 104.65 | 102.20 | 96.70 | |
Table 4. Proportions (% a.r.) of radioactive components in water of the IJzendoorn system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 3.90 | 0.55 | 1.35 | 1.15 | 0.15 | 0.15 | 7.20 |
30 | 2.15 | 0.25 | 0.70 | 1.10 | 0.20 | 0.15 | 4.55 |
63 | 1.95 | 0.45 | 0.45 | 1.25 | 0.80 | 0.10 | 5.00 |
91 | 1.20 | 0.60 | 0.15 | 0.95 | 0.10 | 0.10 | 3.05 |
1 Average of duplicates
Table 5. Proportions (% a.r.) of radioactive components in the sediment extract of the IJzendoorn system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 77.25 | 0.30 | 0.50 | 4.55 | - | - | 82.55 |
30 | 79.10 | 0.50 | 0.50 | 7.15 | - | 0.5 | 87.75 |
63 | 68.45 | 1.00 | 0.65 | 6.85 | 0.70 | 0.10 | 77.75 |
91 | 53.50 | 1.50 | 0.30 | 4.05 | 2.10 | 0.25 | 61.65 |
1 Average of duplicates
Table 6. Proportions (% a.r.) of radioactive components in the total IJzendoorn system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 81.15 | 0.80 | 1.85 | 5.70 | 0.10 | 0.15 | 89.75 |
30 | 81.25 | 0.75 | 1.20 | 8.25 | 0.20 | 0.65 | 92.30 |
63 | 70.40 | 1.45 | 1.10 | 8.10 | 1.50 | 0.20 | 82.75 |
91 | 54.70 | 2.10 | 0.35 | 5.00 | 2.20 | 0.35 | 64.70 |
1 Average of duplicates
Table 7. Proportions (% a.r.) of radioactive components in water of the Lienden system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 24.90 | 2.70 | 4.25 | 2.80 | 0.95 | 0.25 | 35.85 |
30 | 13.80 | 1.35 | 2.50 | 2.70 | 0.50 | 0.40 | 21.25 |
63 | 11.45 | 3.00 | 2.60 | 2.45 | 1.85 | 0.15 | 21.50 |
91 | 5.55 | 4.30 | 0.95 | 3.50 | 0.35 | 0.30 | 14.95 |
1 Average of duplicates
Table 8. Proportions (% a.r.) of radioactive components in the sediment extract of the Lienden system at several time points after application of the test substance (mean of two duplicate vessels1)
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 52.80 | < 0.1 | < 0.10 | 2.80 | 0.95 | - | 56.55 |
30 | 54.65 | 0.50 | < 0.10 | 3.40 | 0.35 | 0.40 | 59.25 |
63 | 43.05 | 1.10 | 0.30 | 2.35 | 0.55 | < 0.10 | 47.35 |
91 | 33.25 | 0.50 | < 0.10 | 2.30 | < 0.10 | < 0.10 | 36.15 |
1 Average of duplicates
Table 9. Proportions (% a.r.) of radioactive components in the total Lienden system at several time points after application of the test substance (mean of two duplicate vessels)1
Incubation time (d) | Pencycuron | Metabolite III (M03) | Metabolite IV (M04) | Metabolite XVI (M16) | Unidentified radioactivity | Residue insoluble in methanol | Total |
14 | 77.70 | 2.70 | 4.25 | 5.60 | 1.90 | 0.25 | 92.40 |
30 | 68.45 | 1.80 | 2.50 | 6.10 | 0.85 | 0.80 | 80.50 |
63 | 54.50 | 4.10 | 2.90 | 4.80 | 2.40 | 0.15 | 68.85 |
91 | 38.80 | 4.80 | 1.00 | 5.80 | 0.35 | 0.35 | 51.10 |
1 Average of duplicates
A separate modelling study was conducted in 2009, which derived level I modelling DT50 and DT90 values for pencycuron and pencycuron-PB-amine, and level II modelling DT50 values for pencycuron, according to the guidance in FOCUS (2005: SANCO/1058/2005 version 1.0).
Remarks by RMS
Description of key information
Two water/sediment systems were treated with [cyclopentyl-3,5-14C]-pencycuron at a concentration of 0.4 mg/L and incubated at 22°C in the dark for 91 days. Mineralisation and formation of non-extractable sediment residues reached maximum levels of 12-22% AR and 24-29% AR, respectively, after 91 days, The levels of pencycuron in the total water/sediment system decreased to 39-55% AR after 91 days. The levels of parent pencycuron reached a maximum in sediment of 55-79% AR on day 30, and decreased to 33-54% AR after 91 days. In water, the levels of parent pencycuron were 3.9-25% AR on day 14, and 1.2-5.6% AR after 91 days. No single metabolite exceeded 10% AR in water or sediment. The main metabolite was pencycuron-PB-amine, detected at maximum levels of 3.5% AR in water and 7.15% AR in sediment. The levels of other metabolites did not exceed 5% AR in water and sediment.
The normalised total system DT50 water/sediment values are 139 days and 82.6 days at 22°C for Ijzendoom and Lienden. When converted to 12°C these values are 354 and 210 days (average value of 282 days).
| Test Type | Result | Assessment | Reference |
| Aerobic water/sediment study guidelines were not specified | The geomean DT50 value of Pencycuron in the total water/sediment system was 107.2 days (at 22°C). This equates to 273 days at 12°C. | Key study | Scholz and Freymiller (1986) |
| Kinetic assessment of water/sediment degradation carried out in line with Focus guidelines. | Total system DT50 values 82.6 and 139 days were calculated at 22°C. These equate to 210 and 354 days at 12°C, respectively. | Key study | Hammel & Kahl (2009) |
| OECD 308 | Mineralisation to CO2 measured as 11.5 - 21.7 % AR in the aerobic water sediment study | Weight of evidence | Scholz and Freymiller (1986) |
| Anaerobic water/sediment study to EPA guidelines | DT50 of 211.5 days at 20°C, (or 448 days at 12°C). Not considered relevant for EU submission. | Not required under REACH | Hellpointner (2003) |
| Aerobic water/sediment study guidelines were not specified | No result, the sediment % in the study was above recommendations (at 27%) | Not accepted in the DAR (too much sediment at 27%) | Leslie and Close (1985) |
Key value for chemical safety assessment
- Half-life in freshwater:
- 282 d
- at the temperature of:
- 12 °C
- Half-life in freshwater sediment:
- 282 d
- at the temperature of:
- 12 °C
Whole System
- Half-life in whole system:
- 282 d
- at the temperature of:
- 12 °C
- Type of system:
- fresh water and sediment
Additional information
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.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
