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EC number: 204-884-0 | CAS number: 128-39-2
- 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

Sediment toxicity
Administrative data
Link to relevant study record(s)
Description of key information
Key value for chemical safety assessment
Additional information
Sediment
Weight of evidence approach
PNEC calculation based on terrestrial Read-Across data
Versonnen et al. 2014 (Sci Total
Environ.2014 Mar 15;475:123-31. doi: 10.1016/j.scitotenv.2013.10.058.
Epub 2013 Nov 14. Analysis of the ecotoxicity data submitted within the
framework of the REACH Regulation: part 4. Experimental terrestrial
toxicity assays. Versonnen B, Tarazona JV, Cesnaitis R, Sobanska MA,
Sobanski T, Bonnomet V, De Coen W.) describe that also for terrestrial
endpoints “Standard REACH information requirements can be adapted on the
basis of REACH column 2 rules for adaptation mentioned above, as well as
on the basis of the 'general rules for adaptation' listed in Annex XI of
the REACH Regulation. These general rules are applicable to all
endpoints and include weight of evidence (WoE) approaches, qualitative
or quantitative structure-activity relationship ((Q)SAR), in vitro
methods, grouping of substances and read-across, indications that
testing is technically not possible, and tailored exposure-driven
approaches”.
Therefore read across data from structural analogues in the “phenols”
category, using the OECD QSAR Toolbox 3.2.0.103 was generated:
Read across data
Test/OECD TG |
Predicted NOEC for 2,6-DTBP, mg/kg soildw |
Range of NOEC values used for read across, mg/kg soildw |
Long-term toxicity to terrestrial invertebrate (earthworm)/OECD 222 |
800 |
125 – 1250 |
Long-term toxicity to terrestrial plants: seedling emergence and growth/OECD 208 |
251 |
113-370 |
Long-term effects on soil microorganisms: nitrogen transformation test/OECD 216 |
399 |
2 – 1250 |
(see below under “Data basis- Newly generated data” for more details)
The read across assessments were
conducted according to the relevant guidance documents and 2,6-DTBP
falls in all three cases into the applicability domain (please see
chapter “Data basis” and Annex 2 for detailed prediction reports in TPRF
(Toolbox Prediction Reporting Format)). Therefore the consortium regards
this data to be scientifically valid.
Following ECHA guidance on PNECsoil calculation using assessment factors
(Table R.10-10 in Chapter R.10) the PNEC soil can be calculated using an
assessment factor (AF) of 10 (with three long-term NOEC values for three
trophic levels available) on the lowest of the three NOECs (251 mg/kg
soil dw).
Accordingly the PNECdry soilwould be 25.1 mg/kg soil dw.
Using as a worst case the lowest experimental NOEC value for the
analogues (2 mg/kg soildw) with an AF of 10 the respective PNECdry
soilcalculates out as 0.2 mg/kg soil dw.
All NOECs over all trophic levels fall into a relatively narrow range
and the NOECs predicted for 2,6-DTBP are well inside this range.
Therefore the consortiums deems these results to be scientifically
justified and applicable for hazard and risk assessment.
PNEC calculation based on newly generated aquatic toxicity data using the EPM method
Calculation of PNEC for sediments using the equilibrium partitioning method (EPM)
To calculate PNEC for freshwater sediment, marine sediment and soil the guidance on how to do this is on Chapter R.10 and R.16.
The equations R.10-2, R.10-3, R.10-5 in ECHA guidance Chapter R.10
The equations use default values and data you have already on the substance.
PNECcomp= Kcomp-water/RHOcomp* PNECwater* 1000
where,
comp' = environmental compartment, e. g. freshwater sediment, marine sediment, suspended matter or soil;
PNECcomp= Predicted No Effect Concentration in wet comp, mg/kg of wet comp;
Kcomp-water= comp-water partitioning coefficient, m³/m³;
RHOcomp= bulk density of wet comp, kg/m³ (= 1150 given); and
PNECwater= Predicted No Effect Concentration in water (freshwater or marine), mg/L.
The unknown term in the above equation is the partitioning coefficient, Kcomp-water, which is derived from equation R.16-7 in ECHA guidance Chapter R.16:
Kcomp-water= Faircomp* Kair-water+ Fwatercomp+ Fsolidcomp* (Kpcomp/1000) * RHOsolid
where,
Faircomp= fraction of air in comp, m³/m³ -- only relevant for soil; Fairsoil= 0.2 m³-air/m³-soil, from Table R.16-9
Kair-water= air-water partitioning coefficient;
Fwatercomp= fraction of water in comp, m³/m³; Fwatersusp= 0.9 m³-water/m³-suspended matter, Fwatersed= 0.8 m³-water/m³-sediment, Fwatersoil= 0.2 m³-water/m³-soil, from Table R.16-9
Fsolidcomp= fraction of solids in comp, m³/m³; Fsolidsusp= 0.1 m³-soilds/m³-suspended matter, Fsolidsed= 0.2 m³-soilds/m³-sediment, Fsolidsoil = 0.6 m³-soilds/m³-soil, from Table R.16-9
Kpcomp= solids-water partitioning coefficient in comp, L/kg;
Kpcomp= Foccomp* Koc equation R.16-6
where,
Foccomp= weight fraction organic carbon in comp solids, kg-oc/kg-solids;
Focsusp= 0.1 kg-oc/kg-solid
Focsed= 0.05 kg-oc/kg-solid
Focsoil= 0.02 kg-oc/kg-solid
Koc = partitioning coefficient organic carbon-water (4493 L/kg -- from data set for the substance being registered)
RHOsolid= density of the solid phase, kg/m³ (= 2500 given).
Compartment |
PNECcomp |
Kcomp-water |
RHOcomp |
PNECwater |
Faircomp |
Kair-water |
Fwatercomp |
Fsolidcomp |
Kpcomp |
RHOsolid |
Foccomp |
Koc |
HLC |
v. p |
MW |
water solubility |
|
mg/kg of wet comp |
m3/m3 |
kg/m3 |
mg/L |
m3/m3 |
|
m3/m3 |
m3/m3 |
L/kg |
kg/m3 |
kg/kg |
|
Pa-m3/mole |
Pa |
g/mole |
mg/L |
freshwater sediment |
0.0689 |
113 |
1150 |
0.0007 |
NA |
NA |
0.9 |
0.1 |
477 |
2500 |
0.1 |
4493 |
|
|
|
|
marine sediment |
0.00689 |
113 |
1150 |
0.000070 |
NA |
NA |
0.9 |
0.1 |
477 |
2500 |
0.1 |
4493 |
|
|
|
|
soil |
0.0556 |
135 |
1150 |
0.0007 |
0.2 |
0.0145 |
0.2 |
0.6 |
95.4 |
2500 |
0.02 |
4493 |
34.3 |
1.01 |
206.33 |
4.11 |
PNECfreshwater= 0.0007 mg/L
PNECmarine water= 0.000070 mg/L
Koc = 4493
MW = 206.33
water solubility = 4.11 mg/L
vapour pressure = 1.01 Pa
PNECfreshwater wet sediment= 0.0689 mg/kg ww
PNECfreshwater dry sediment= 0.317 mg/kg dw
PNECmarine wet sediment= 0.00689 mg/kg ww
PNECmarine dry sediment= 0.0317 mg/kg dw
PNECwet soil= 0.0556 mg/kg ww
PNECdry soil= 0.063 mg/kg dw
Conclusion on sediment toxicity
Comparison of PNECdry soil:
Data base |
PNECdry soil |
Based on three available long-term terrestrial studies for the registered substance (this dossier) |
0.693 mg/kg soil dw (experimentally determined) |
Based on the EPM method (calculation performed as described above) |
0.063 mg/kg dwn (calculated with EPM-method) |
The comparison of PNECdry soil values shows that using the Daphnia magna reproduction test data in combination with the EPM method leads to the lowest (=more conservative) PNECdry soilvalue. The comparison with the respective value derived from terrestrial long-term studies clearly indicates that the EPM value is significantly more conservative. Based on the outcome of this analysis, the registered substance has no properties which makes it more toxic to soil organisms than predicted by the EPM method. It can be assumed that this is also true for sediment organisms. As shown for the soil compartment, we consider the calculation of the PNEC sediment by the EPM method as conservative.
In addition column 2 of the Corrigendum to Regulation (EC) No 1907/2006, Annex X, states, “Long-term toxicity testing shall be proposed by the registrant if the results of the chemical safety assessment indicates the need to investigate further the effects of the substance and/or relevant degradation products on sediment organisms. The choice of the appropriate test(s) depends on the results of the chemical safety assessment”
The risk assessment based on the result of the (conservative) equilibrium partitioning method does not indicate any cause for concern with regard to the sediment. The RCRs for the sediment were all less than 1.
Based on the above, the waiving of sediment studies according to column 2 is considered to be justified.
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