Registration Dossier
Registration Dossier
Diss Factsheets
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: 203-674-6 | CAS number: 109-46-6
- 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 respiration inhibition testing
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 2015
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
- GLP compliance:
- yes (incl. QA statement)
- Specific details on test material used for the study:
- None.
- Analytical monitoring:
- no
- Details on sampling:
- n.a.
- Vehicle:
- no
- Details on test solutions:
- The synthetic sewage feed was prepared to contain the following constituents per liter:
- 16 g peptone
- 11 g meat extract
- 3 g urea
- 0.7 g sodium chloride
- 0.4 g calcium chloride dihydrate CaCl2, 2H2O
- 0.2 g magnesium sulfate heptahydrate MgSO4, 7H2O
- 2.8 g di-potassium hydrogen phosphate K2HPO4
The final volume was filled up with ultra-pure water. - Test organisms (species):
- activated sludge of a predominantly domestic sewage
- Details on inoculum:
- The inoculum was obtained on 31 August 2015 from the activated sludge of the biological wastewater treatment plant from Abidos (France, 64) which handles predominantly domestic sewage. On arrival at the laboratory, the activated sludge (around 10L) was centrifuged (1000g for 10 minutes) and the solid sewage inoculum pellet was re-suspended in 10L French source water (Volvic®). 500 mL synthetic sewage feed was then added. Sewage sludge was maintained under aerated conditions for a maximum of 4 days and fed daily with synthetic sewage feed at a rate of 50 mL/L. In order to obtain the required sludge suspended solids concentration of 3 g/L in the stock solution to be used in the experiments, the solid content of the 10-L sludge solution was determined by removing a sub-sample of homogenised sludge and drying it an oven at approximately 105°C. The suspended solids concentration was subsequently adjusted to the recommended guideline value of 3 g/L ± 10%.
- Test type:
- static
- Water media type:
- freshwater
- Limit test:
- no
- Total exposure duration:
- 3 h
- Remarks on exposure duration:
- None.
- Hardness:
- Not reported.
- Test temperature:
- 19.6°C - 21.2°C (min - max)
- pH:
- 7.4 - 7.6 (min - max)
- Dissolved oxygen:
- Around 8 mg/L during the 3-h incubation and around 8 mg/L at the beginning of the 10-min incubation period with oxygen depletion monitoring.
- Salinity:
- Freshwater.
- Conductivity:
- Not reported
- Nominal and measured concentrations:
- Nominal test item concentrations: 0 ; 1 ; 3.2 ; 10 ; 32 ; 100 mg/L
Nominal reference item concentrations: 0 ; 3.2 ; 10 ; 32 mg/L - Details on test conditions:
- At the start of the test, 16 mL of synthetic sewage feed were made up to 250 mL with ultra-pure water and 250 mL activated sludge inoculum with a sludge concentration of nominally 1.5 g/L (dry weight) were added to the first control vessels couple. Thereafter, at time intervals of about fifteen minutes, the procedure was repeated with test vessels couples in which the 16 mL of synthetic sewage were made up to 250 mL with the appropriate amounts of reference or test item diluted in ultra-pure water to obtain a volume of 250 mL. As for the controls, 250 mL of activated sludge inoculum (1.5 g/L) were then added. Fifteen minutes after the preparation of the last treatment, the second control vessels couple was prepared at last. The fifteen minutes interval was done so that the 10 min incubation period with O2 depletion monitoring could take place exactly 3 hours after start of incubation of each test vessel. The addition of the inoculum was considered as the start of the 3-hours incubation time period.
All solutions were incubated at 20 +/- 2°C in darkness for 3 hours in a temperature controlled room. Solutions were mixed by stirring and aerated with clean, oil-free compressed air via narrow bore glass tubes at a rate of 0.5 to 1.0 liter per minute during 3 hours. At the end of the test incubation period, a well-mixed sample of each solution (following their order of preparation) were poured into a BOD bottle in which dissolved oxygen concentrations were measured at 1 min intervals for up to a maximum period of 10 min or until the oxygen concentration felt below 1 mg/L.
The temperature was monitored throughout the test period. - Reference substance (positive control):
- yes
- Remarks:
- 3,5-dichlorophenol ; CAS 951-35-5
- Key result
- Duration:
- 3 h
- Dose descriptor:
- NOEC
- Effect conc.:
- >= 100 mg/L
- Nominal / measured:
- nominal
- Conc. based on:
- act. ingr.
- Basis for effect:
- inhibition of total respiration
- Details on results:
- 1,3-dibutylthiourea did not cause any significant respiratory inhibition up to the highest tested concentration. The NOEC is therefore considered superior or equal to 100 mg/L. This test met the validity criteria of the guideline:
- The coefficient of variation of oxygen uptake rate in the controls should be no more than 30% at the end of the definitive test: the maximum was determined to be 8.1%
- The blank controls oxygen uptake was not less than 20 mg oxygen/g of activated sludge (dry weight of suspended solids) in an hour: min. 29.80 mg O2/g of activated sludge (dry weight of suspended solids)/h - Results with reference substance (positive control):
- The 3h-EC50 for 3,5-dichlorophenol to activated sludge was estimated under the conditions of the test as follows: 17.0 mg/L for total respiration. The test with 1,3-dichlorophenol met the validity criteria of the guideline:
- The coefficient of variation of oxygen uptake rate in the controls should be no more than 30% at the end of the definitive test: the maximum was determined to be 1.3%
- The 3h-EC50 for 3,5-dichlorophenol (17.0 mg/L) was between 2 and 25 mg/L for total respiration
- The blank controls oxygen uptake was not less than 20 mg oxygen/g of activated sludge (dry weight of suspended solids) in an hour: 34.72 and 35.36 mg O2/g of activated sludge (dry weight of suspended solids)/h - Reported statistics and error estimates:
- LOEC and NOEC for respiration inhibition were calculated using appropriate statistical methods with the software ToxRatPro Version 3.1.0®. ECx-values and their associated lower and upper 95% confidence limits could not be determined because the test item actually had no effects.
- Validity criteria fulfilled:
- yes
- Conclusions:
- 1,3-dibutylthiourea did not cause any significant respiratory inhibition up to the highest tested concentration. The NOEC is therefore considered superior or equal to 100 mg/L.
- Executive summary:
This GLP OECD 209 study was carried out in order to determine the 3h-EC50 and 3h-NOEC of 1,3 -dibutythiourea on total respiration inhibition of activated sludge. The inoculum was obtained on 31 August 2015 from the activated sludge of the biological wastewater treatment plant from Abidos (France, 64) which handles predominantly domestic sewage. The sludge was prepared so as to obtain a 10 -L stock solution at a concentration of 3g/L of suspended solids (dry weight) diluted in Volvic water medium supplemented with a synthetic sewage feed.
At the start of the test, 16 mL of synthetic sewage feed were made up to 250 mL with ultra-pure water and 250 mL activated sludge inoculum with a sludge concentration of nominally 1.5 g/L (dry weight) were added to the first control vessels couple. Thereafter, at time intervals of about fifteen minutes, the procedure was repeated with test vessels couples in which the 16 mL of synthetic sewage were made up to 250 mL with the appropriate amounts of reference or test item diluted in ultra-pure water to obtain a volume of 250 mL. As for the controls, 250 mL of activated sludge inoculum (1.5 g/L) were then added. Fifteen minutes after the preparation of the last treatment, the second control vessels couple was prepared at last. The fifteen minutes interval was done so that the 10 min incubation period with O2 depletion monitoring could take place exactly 3 hours after start of incubation of each test vessel. The addition of the inoculum was considered as the start of the 3-hours incubation time period. All solutions were incubated at 20 +/- 2°C in darkness for 3 hours in a temperature controlled room. Solutions were mixed by stirring and aerated with clean, oil-free compressed air via narrow bore glass tubes at a rate of 0.5 to 1.0 liter per minute during 3 hours. At the end of the test incubation period, a well-mixed sample of each solution (following their order of preparation) were poured into a BOD bottle in which dissolved oxygen concentrations were measured at 1 min intervals for up to a maximum period of 10 min or until the oxygen concentration felt below 1 mg/L. The temperature was monitored throughout the test period. 1,3-dibutylthiourea did not cause any significant respiratory inhibition up to the highest tested concentration. The NOEC is therefore considered superior or equal to 100 mg/L. The 3h-EC50 for 3,5-dichlorophenol to activated sludge was 17.0 mg/L for total respiration. The test met all the validity criteria of the guideline.
Reference
Total respiration was inhibited at each tested concentrations as described below:
Test item nominal concentration (mg/L) |
Inhibition of total respiration (%) |
1.0 |
6.8 |
3.2 |
1.9 |
10.0 |
4.5 |
32.0 |
3.3 |
100.0 |
8.6 |
Description of key information
This GLP OECD 209 study was carried out in order to determine the 3h-EC50 and 3h-NOEC of 1,3 -dibutythiourea on total respiration inhibition of activated sludge. The inoculum was obtained on 31 August 2015 from the activated sludge of the biological wastewater treatment plant from Abidos (France, 64) which handles predominantly domestic sewage. The sludge was prepared so as to obtain a 10 -L stock solution at a concentration of 3g/L of suspended solids (dry weight) diluted in Volvic water medium supplemented with a synthetic sewage feed.
At the start of the test, 16 mL of synthetic sewage feed were made up to 250 mL with ultra-pure water and 250 mL activated sludge inoculum with a sludge concentration of nominally 1.5 g/L (dry weight) were added to the first control vessels couple. Thereafter, at time intervals of about fifteen minutes, the procedure was repeated with test vessels couples in which the 16 mL of synthetic sewage were made up to 250 mL with the appropriate amounts of reference or test item diluted in ultra-pure water to obtain a volume of 250 mL. As for the controls, 250 mL of activated sludge inoculum (1.5 g/L) were then added. Fifteen minutes after the preparation of the last treatment, the second control vessels couple was prepared at last. The fifteen minutes interval was done so that the 10 min incubation period with O2 depletion monitoring could take place exactly 3 hours after start of incubation of each test vessel. The addition of the inoculum was considered as the start of the 3-hours incubation time period. All solutions were incubated at 20 +/- 2°C in darkness for 3 hours in a temperature controlled room. Solutions were mixed by stirring and aerated with clean, oil-free compressed air via narrow bore glass tubes at a rate of 0.5 to 1.0 liter per minute during 3 hours. At the end of the test incubation period, a well-mixed sample of each solution (following their order of preparation) were poured into a BOD bottle in which dissolved oxygen concentrations were measured at 1 min intervals for up to a maximum period of 10 min or until the oxygen concentration felt below 1 mg/L. The temperature was monitored throughout the test period. 1,3-dibutylthiourea did not cause any significant respiratory inhibition up to the highest tested concentration. The NOEC is therefore considered superior or equal to 100 mg/L. The 3h-EC50 for 3,5-dichlorophenol to activated sludge was 17.0 mg/L for total respiration. The test met all the validity criteria of the guideline.
Key value for chemical safety assessment
- EC10 or NOEC for microorganisms:
- 100 mg/L
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.
