2-hydroxypyridine 1-oxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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:

Data is from OECD QSAR toolbox version 3.3 and the QMRAF report has been attached.

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using the OECD QSAR toolbox version 3.3.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 2-Hydroxypyridine 1-oxide
- Molecular formula : C5H5NO2
- Molecular weight : 111.1 g/mol
- Smiles notation : n1(c(O)cccc1)=O
- InChl : 1S/C5H5NO2/c7-5-3-1-2-4-6(5)8/h1-4,7H
- Substance type: Organic
- Physical state: Solid

Analytical monitoring:

not specified

Details on sampling:

No data available

Vehicle:

not specified

Details on test solutions:

No data available

Test organisms (species):

Daphnia magna

Details on test organisms:

- Common name: Water flea

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

No data available

Post exposure observation period:

No data available

Hardness:

60 mg/L CaCO3

Test temperature:

22 ± 1 ºC

pH:

7.0– 7.3

Dissolved oxygen:

6.8 mg/L (77 % saturation) to 8.3 mg/L (94 % saturation)

Salinity:

No data available

Conductivity:

No data available

Nominal and measured concentrations:

Nominal

Details on test conditions:

No data available

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

180.95 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

other: Intoxication

Remarks on result:

other: Data is predicted

Details on results:

No data available

Results with reference substance (positive control):

No data available

Reported statistics and error estimates:

No data available

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

((((((((("a" or "b" or "c" or "d" or "e" )  and ("f" and ( not "g") )  )  and "h" )  and "i" )  and ("j" and ( not "k") )  )  and ("l" and ( not "m") )  )  and "n" )  and "o" )  and ("p" and "q" )  )

Domain logical expression index: "a"

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

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Aryl OR Heterocyclic Phenol OR N-Oxide OR Pyridine by Organic Functional groups ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Heterocyclic Phenol OR N-Oxide OR Overlapping groups by Organic Functional groups (nested) ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Alcohol, olefinic attach [-OH] OR Aromatic Carbon [C] OR Aromatic Nitrogen OR Hydroxy, aromatic attach [-OH] OR Miscellaneous sulfide (=S) or oxide (=O) OR Nitrogen oxide, aromatic nitrogen [n=O] OR Nitrogen oxide, aromatic nitrogen [n=O] non fused  OR Olefinic carbon [=CH- or =C<] OR Oxygen, one aromatic attach [-O-] OR Pyridine, non fused rings  by Organic functional groups (US EPA) ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Aromatic compound OR N-oxide OR Phenol by Organic functional groups, Norbert Haider (checkmol) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as No alert found by DNA binding by OASIS v.1.3

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as AN2 OR AN2 >> Nucleophilic addition to alpha, beta-unsaturated carbonyl compounds OR AN2 >> Nucleophilic addition to alpha, beta-unsaturated carbonyl compounds >> alpha, beta-Unsaturated Aldehydes OR AN2 >> Schiff base formation OR AN2 >> Schiff base formation >> alpha, beta-Unsaturated Aldehydes OR Non-covalent interaction OR Non-covalent interaction >> DNA intercalation OR Non-covalent interaction >> DNA intercalation >> DNA Intercalators with Carboxamide Side Chain OR Radical OR Radical >> Radical mechanism by ROS formation OR Radical >> Radical mechanism by ROS formation >> Polynitroarenes OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroarenes with Other Active Groups OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitrophenols, Nitrophenyl Ethers and Nitrobenzoic Acids OR Radical >> Radical mechanism via ROS formation (indirect) >> Single-Ring Substituted Primary Aromatic Amines OR SN1 OR SN1 >> Alkylation after metabolically formed carbenium ion species OR SN1 >> Alkylation after metabolically formed carbenium ion species >> Polycyclic Aromatic Hydrocarbon Derivatives OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation >> Nitroarenes with Other Active Groups OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Single-Ring Substituted Primary Aromatic Amines OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroarenes with Other Active Groups OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitrophenols, Nitrophenyl Ethers and Nitrobenzoic Acids OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Polynitroarenes OR SN2 OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation >> Polycyclic Aromatic Hydrocarbon Derivatives OR SN2 >> Direct acting epoxides formed after metabolic activation OR SN2 >> Direct acting epoxides formed after metabolic activation >> Quinoline Derivatives OR SN2 >> SN2 at an activated carbon atom OR SN2 >> SN2 at an activated carbon atom >> Quinoline Derivatives OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 >> Nitroarenes with Other Active Groups by DNA binding by OASIS v.1.3

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Class 5 (Not possible to classify according to these rules) by Acute aquatic toxicity classification by Verhaar (Modified) ONLY

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Very fast by Bioaccumulation - metabolism half-lives ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Alkali Earth OR Halogens OR Transition Metals by Groups of elements

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Group 14 - Carbon C AND Group 15 - Nitrogen N AND Group 16 - Oxygen O by Chemical elements

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Group 16 - Sulfur S by Chemical elements

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Aryl AND Heterocyclic Phenol AND N-Oxide AND Pyridine by Organic Functional groups ONLY

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Heterocyclic Phenol AND N-Oxide AND Overlapping groups by Organic Functional groups (nested) ONLY

Domain logical expression index: "p"

Parametric boundary:The target chemical should have a value of log Kow which is >= -1.93

Domain logical expression index: "q"

Parametric boundary:The target chemical should have a value of log Kow which is <= 0.613

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 value was estimated to be 180.94 mg/l when 2-Hydroxypyridine 1-oxide was exposed to Daphnia magna for 48hrs.

Executive summary:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, toxicity on Daphnia magna was predicted for 2-Hydroxypyridine 1-oxide (13161-30-3).The EC50 value was estimated to be 180.94 mg/l when 2-Hydroxypyridine 1-oxide was exposed to Daphnia magna for 48hrs.

Description of key information

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, toxicity on Daphnia magna was predicted for 2-Hydroxypyridine 1-oxide (13161-30-3).The EC50 value was estimated to be 180.94 mg/l when 2-Hydroxypyridine 1-oxide was exposed to Daphnia magna for 48hrs.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

180.94 mg/L

Additional information

The toxicity of the chemical 2-Hydroxypyridine 1-oxide (13161-30-3) on the growth of aquatic invertebrates was studied by considering and collecting the data from various databases for target chemical. Some RA (read across) chemicals were also studied. The result are summarised as below:

In the first weight of evidence study for 2-Hydroxypyridine 1-oxide (13161-30-3) based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, toxicity on Daphnia magna was predicted for 2-Hydroxypyridine 1-oxide (13161-30-3).The EC50 value was estimated to be 180.94 mg/l when 2-Hydroxypyridine 1-oxide was exposed to Daphnia magna for 48hrs.

 

In the second weight of evidence study for target chemical 2-Hydroxypyridine 1-oxide (13161-30-3) ECOSAR, 2017. Based on the prediction done by EPI suite, ECOSAR version 1.1, on the basis of similarity of structure to chemicals for which the aquatic toxicity has been previously measured by structure-activity relationships (SARs) program, the LC 50 value for short term toxicity to aquatic invertebrates was predicted. On the basis of this program, the LC 50 value for short term toxicity to aquatic invertebrates was predicted to be 22147 mg/l 2- Hydroxy -pyridine 1-oxide in 48 hrs. Based on this value it can be concluded that the substance is considered to be not toxic to aquatic environment and cannot be classified as toxic as per the criteria mentioned in CLP regulation.

 

Similarly in the third weight of evidence study for RA chemical (108-80-5) J-check, Short-term toxicity study of Isocyanuric acid on the mobility of aquatic invertebrates for 48 hrs. Test was performed in static conditions. Based on the immobilization of daphnia due to Isocyanuric acid, the EC50 was 1000mg/l. Based on the EC50 value, the chemical Isocyanuric acid was not toxic and can be consider to be classified as nontoxic as per the CLP classification criteria.

 

Similarly in the fourth weight of evidence study for another RA chemical 123-33-1 (1,2-Dihydro-3,6-pyridazinedione) from HSDB and ECOTOX, 2017, Short term toxicity of Maleic hydrazide (1,2-Dihydro-3,6-pyridazinedione) on the growth of daphnia magna was studied for 48 hrs. Test was performed by static system on 1 ins age of fish. Based on the intoxication of daphnia magna by the exposure of Maleic hydrazide (1,2-Dihydro-3,6-pyridazinedione) the EC50 was 107.5 mg/l. Based on the EC50 value Maleic hydrazide (1,2-Dihydro-3,6-pyridazinedione) was not toxic and cannot be consider as classified as toxic to aquatic environment as per the CLP classification criteria.

Based on the data from various sources, it can be concluded that the substance 2-Hydroxypyridine 1-oxide is likely to be not toxic at environmentally relevant concentrations and can be considered as 'not classified' as per the criteria mentioned in CLP regulation.