4,4'-oxydi(benzenesulphonohydrazide)

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Data waiving:

other justification

Justification for data waiving:

other:

Justification for type of information:

In accordance with column 2 of REACH Annex IX, section 9.2., further biotic degradation testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the degradation of the substance and its degradation products. The CSA does not indicate the need for further testing since RCRs are well below 1 for all environmental compartments, thus demonstrating safe use (highest RCR (OBSH) = 0.025 for agricultural soil, highest RCR (hydrazine) = 0.036 for fresh water). According to the ITS described in ECHA Guidance on Information Requirements and CSA, R.7b (Figure R.7.9-3), sufficient data is available fulfilling the three regulatory needs, i.e. environmental hazard classification, PBT/vPvB assessment and exposure assessment. Furthermore, according to the ECHA Guidance R.7b, simulation studies may be required for a substance to refine the persistence assessment for a substance. Even though OBSH and its two transformation products hydrazine hydrate and 4,4’-oxybis(benzenesulfonic acid) are not considered readily biodegradable, a PBT/vPvB concern can be ruled out since neither of the substances are bioaccumulative (please refer to the cross-references).

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Assessed substance:

transformation product

PBT status of the assessed substance:

the substance is not PBT / vPvB

Remark:

Hydrazine is inorganic and therefore the concept of biodegradability does not apply.
Hydrazine will degrade in aqueous media in the presence of metal ions and organic matter. The time for complete degradation will depend on the presence of both factors. Base on available experimental studies, the environmental half life of hydrazine in the aquatic compartment will be < 40 days and thereby the P criterion. is not fulfilled.

Conclusion on P / vP properties:

not P/vP

Remark:

There is no experimental BCF available. The estimated BCF is 3.16 (log BCF 0.5, BCFBAF v3.02). Furthermore, rapid degradation and a low log Kow combined with high water solubility lead to the conclusion that the potential to bioaccumulate is low.

Conclusion on B / vB properties:

not B/vB

other evidence

Remark:

Hydrazine is classified as Carc. Cat. 2.

Conclusion on T properties:

T

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Assessed substance:

transformation product

PBT status of the assessed substance:

the substance is not PBT / vPvB

Remark:

There are no experimental data available. Based on in silico data generated by EPI Suite's BIOWIN models, 4,4’-oxybis(benzenesulfonic acid) does not biodegrade fast. The model Biodegradation ultimate (Biowin 3) indicates weeks-months for ultimate biodegradation.
The PBT Prioritizing Scheme integrated in the QECD QSAR Toolbox 4.4.1 indicates: P, not B.

--------------------------- BIOWIN v4.10 Results ----------------------------

SMILES : OS(=O)(=O)c1ccc(Oc2ccc(cc2)S(O)(=O)=O)cc1
CHEM :
MOL FOR: C12 H10 O7 S2
MOL WT : 330.33

--------------------------- BIOWIN v4.10 Results ----------------------------
Biowin1 (Linear Model Prediction) : Does Not Biodegrade Fast
Biowin2 (Non-Linear Model Prediction): Does Not Biodegrade Fast
Biowin3 (Ultimate Biodegradation Timeframe): Weeks-Months
Biowin4 (Primary Biodegradation Timeframe): Days-Weeks
Biowin5 (MITI Linear Model Prediction) : Not Readily Degradable
Biowin6 (MITI Non-Linear Model Prediction): Not Readily Degradable
Biowin7 (Anaerobic Model Prediction): Does Not Biodegrade Fast
Ready Biodegradability Prediction: NO

Conclusion on P / vP properties:

No conclusion can be reached based on available information

Remark:

There are no experimental data available. Based on in silico data generated by EPI Suite's BIOWIN models, 4,4’-oxybis(benzenesulfonic acid) does not biodegrade fast. The model Biodegradation ultimate (Biowin 3) indicates weeks-months for ultimate biodegradation.
The PBT Prioritizing Scheme integrated in the QECD QSAR Toolbox 4.4.1 indicates: P, not B.

Not B and not vB based on: Log Kow ≤ 4.5

Remark:

There is no experimental data available. Based on in silico calculations, the estimated log Kow is -0.06.

KOWWIN Program (v1.68) Results:
Log Kow(version 1.69 estimate): -0.06

Not B and not vB based on: BCF ≤ 2,000 L/kg

Remark:

There are no experimental data available. Based on in silico calculations, the estimated BCF is 3.16 L/kg wet-wt.

BCFBAF v3.01:
Summary Results:
Log BCF (regression-based estimate): 0.50 (BCF = 3.16 L/kg wet-wt)
Biotransformation Half-Life (days) : 0.0715 (normalized to 10 g fish)
Log BAF (Arnot-Gobas upper trophic): -0.02 (BAF = 0.962 L/kg wet-wt)

Log Kow (experimental): not available from database
Log Kow used by BCF estimates: -0.06

Equation Used to Make BCF estimate:
Log BCF = 0.50 (Ionic; Log Kow dependent)

Estimated Log BCF = 0.500 (BCF = 3.162 L/kg wet-wt)

Conclusion on B / vB properties:

not B/vB

Remark:

Based on the available data, the 4,4’-oxybis(benzenesulfonic acid) is not bioaccumulative. The PBT Prioritizing Scheme integrated in the QECD QSAR Toolbox 4.4.1 indicates: P, not B.

Conclusion on T properties:

No conclusion can be reached based on available information

Remark:

There are no data available. The automated workflow provided in the OECD QSAR Toolbox v. 4.4.1 cannot predict the LC50 for fish. In conclusion, no information on toxicity for 4,4’-oxybis(benzenesulfonic acid) is available.

Results and discussion

Transformation products:

yes

Identity of transformation products

Identity of transformation products 1

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

Hydrazine, hydrate

CAS number:

10217-52-4

Identity:

Hydrazine, monohydrate

Identifier:

EC number

Identity:

10217-52-4

Molecular formula:

H6N2O

Molecular weight:

50

SMILES notation:

NN.O

Identity of transformation products 2

No.:

#2

Reference

Reference substance name:

Unnamed

IUPAC name:

4,4’-oxybis(benzenesulfonic acid)

CAS number:

NA

Molecular formula:

C12H10O7S2

Molecular weight:

330

SMILES notation:

OS(=O)(=O)c1ccc(Oc2ccc(cc2)S(=O)(=O)O)cc1