1-phenylazo-2-naphthol

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

The prediction is done using OECD QSAR toolbox version 3.3 and the supporting QMRF report has been attached.

Qualifier:

no guideline available

Principles of method if other than guideline:

The prediction is done using OECD QSAR toolbox version 3.3.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report):C. I. Solvent Yellow 14
- Molecular formula : C16H12N2O
- Molecular weight: 248.284 g/mole
- Substance type: Organic
- Physical state: Solid

Radiolabelling:

not specified

Analytical monitoring:

not specified

Positive controls:

not specified

Negative controls:

not specified

Transformation products:

not specified

Temp.:

25 °C

DT50:

108.89 d

Type:

other: Estimated

Remarks on result:

other: other details not available

Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

((((((("a" or "b" or "c" )  and "d" )  and "e" )  and "f" )  and "g" )  and ("h" and ( not "i") )  )  and ("j" and "k" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Aromatic azo by DNA binding by OECD

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Strong binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Phenols by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Not calculated by Hydrolysis half-life (pH 6.5-7.4) ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as days - weeks by Biodeg primary (Biowin 4) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Biodegrades Fast by Biodeg probability (Biowin 1) ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 7) ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Phenols by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Aromatic amines OR Ketones by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 192 Da

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 425 Da

Validity criteria fulfilled:

not specified

Conclusions:

The half-life of 1-phenylazo-2-naphthol was estimated to be 108.89 days at temperature 25degC, indicating that the substance 1-phenylazo-2- naphthol is not hydrolysable.

Executive summary:

The hydrolysis study of 1-phenylazo-2-naphthol was predicted using OECD QSAR toolbox version 3.3 (2017) to predict the hydrolysis half-life of test compound 1-phenylazo-2-naphthol (CAS No.842-07 -9). The half-life of 1-phenylazo-2-naphthol was estimated to be 108.89 days at temperature 25degC, indicating that the substance 1-phenylazo-2-naphthol is not hydrolysable.

Description of key information

The hydrolysis study of 1-phenylazo-2-naphthol was predicted using OECD QSAR toolbox version 3.3 (2017) to predict the hydrolysis half-life of test compound 1-phenylazo-2-naphthol (CAS No.842-07 -9). The half-life of 1-phenylazo-2-naphthol was estimated to be 108.89 days at temperature 25degC, indicating that the substance 1-phenylazo-2-naphthol is not hydrolysable.

Key value for chemical safety assessment

Half-life for hydrolysis:

108.89 d

at the temperature of:

25 °C

Additional information

In a different studies, 1-phenylazo-2-naphthol (CAS No. 842 -07 -9) has been investigated for its hydrolysis potential to a greater or lesser extent. These include predicted and experimental study for target substance 1-phenylazo-2-naphthol (CAS No. 842 -07 -9) and for its closest read across substance 1-[(2,5-dimethoxyphenyl)diazenyl]-2-naphthol (Citrus Red 2) (CAS No.- 6358-53-8) by considering its structure-activity relationships, were reviewed and are summarized as follows:

 

The hydrolysis study of 1-phenylazo-2-naphthol was predicted by SSS (2017) using OECD QSAR toolbox version 3.3 (2017) to predict the hydrolysis half-life of test compound 1-phenylazo-2-naphthol (CAS No.842-07 -9). The half-life of 1-phenylazo-2-naphthol was estimated to be 108.89 days at temperature 25degC, indicating that the substance 1-phenylazo-2-naphthol is not hydrolysable.

 

This is supported by the study from an authoritative database (Hazardous Substances Data Bank (HSDB);2017) for a read across substance 1-[(2,5- dimethoxy phenyl)diazenyl]-2-naphthol (Citrus Red 2) (CAS No.- 6358-53-8).The substance 1-[(2,5-dimethoxyphenyl)diazenyl]-2-naphthol (Citrus Red 2) (CAS No.- 6358- 53-8) is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions.

  

Based on the above available studies for the target and read across substance, it can be concluded that the test substance 1-phenylazo-2-naphthol (CAS No. 842 -07 -9) is not expected to undergo hydrolysis in the environment i.e., it is not hydrolysable.