Pyridine-2-carbaldehyde

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

key study

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 adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
EPIWIN software by US-EPA

2. MODEL (incl. version number)
ECOSAR v1.11

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
O=Cc(nccc1)c1

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- The model and the training and validation sets are published by US Environmental Protection Agency (USA). Details in addition to the summary provided here can be found in the program.
- Defined endpoint:
ECOSAR study criteria articulate that the toxicity should be measured at pH 7 (replicating environmental conditions), the total organic carbon content should not exceed 2 mg/L, the water hardness should be approximately 150 mg/L CaCO3, results should be adjusted to, or measured at, 100% active ingredient, and flow-through measured is preferred over static nominal, etc. Data received or identified in the open literature which is not accompanied with full study details to confirm conditions are often not considered appropriate for model development. Therefore, many measured ecotoxicity data points can be found in the open literature which are not considered suitable for inclusion in the ECOSAR model.
When collecting studies for inclusion in the training sets, standard test species were preferred as identified in OPPTS guidelines for aquatic toxicity testing. For freshwater fish data, species frequently include bluegill sunfish (Lepomis macrochirus), common carp (Cyprinus carpio), fathead minnow (Pimephales promelas), guppy (Poecilia reticulate), rainbow trout (Oncorhynchus mykiss), red killifish (Oryzias latipes), or zebrafish (Brachydanio rerio). For freshwater invertebrates, species frequently include Daphnia magna or Daphnia pulex. For freshwater algae, species frequently include Desmodesmus subspicatus or Pseudokirchneriella subcapitata. Therefore, the equations in ECOSAR are derived from surrogate species of fish, zooplankton, and phytoplankton.
- Unambiguous algorithm: After collecting the training set information for each chemical including estimated log Kow and valid toxicity results, regression techniques are applied to the class-specific data sets to derive mathematical relationships between log Kow and toxicity (often called the resulting algorithm). These resulting class-specific equations typically take the form of y = mx + b, where “y” represents the toxic effect concentration (i.e. log LC50 in mmol/L) and “x” represents the log Kow value. Using these resulting linear equations, toxicity values (mmol/L) for untested chemicals may then be calculated in a three-step process: (1) select the appropriate class using the ECOSAR class definitions, (2) input the measured or estimated log Kow value of the molecule into the mathematical regression equation to estimate the toxic effect concentration (mmol/L), (3) use molecular weight of the subject chemical to convert the estimated effect concentration from mmol/L to mg/L for use in aquatic toxicity hazard profiles. The computerized ECOSAR program is designed to automatically complete all three steps when providing estimates based on the users chemical input.
- Defined domain of applicability: EPI Suite cannot be used for all chemical substances. The intended application domain is organic chemicals. Inorganic and organometallic chemicals generally are outside the domain. To estimate the toxicity to aquatic organisms of neutral organics and organic classes with excess toxicity, the log Kow and molecular weight are required. In general, when the log Kow is less than or equal to 5.0 for fish and daphnid, or 6.4 for green algae, ECOSAR provides reliable quantitative (numeric) toxicity estimates for acute effects. For chronic exposures, the applicable log Kow range to derive reliable quantitative (numeric) values is extended up to log Kow 8.0. In the development of the ECOSAR equations for neutral organics and classes with excess toxicity, the training sets generally include chemicals with log Kow values in the range of -3 to 8 and molecular weights less than 1000. However, the domain of the model is considered to be larger than the descriptor range of the training set of chemicals.

5. APPLICABILITY DOMAIN
- Descriptor domain: 2-Pyridinecarboxaldehyde is an organic chemical with a molecular weight of 107.11 g/mol, its logPow is 0.714 at pH 6.4-6.8, and hence falls into the applicability domain of the model providing accurate results.
- Structural and mechanistic domains: The substance falls hence in the structural domain of the model (Aldehydes - Mono)
- Similarity with analogues in the training set: There are currently 130 chemical classes programmed into ECOSAR: Acid Chlorides/Halides, Acrylamides, Acrylates, Aldehydes - Mono, Aldehydes - Poly, Aliphatic Amines, Allyl / Vinyl Aldehydes, Allyl / Vinyl Alcohols, Allyl / Vinyl Ethers, Allyl / Vinyl Halides, Allyl / Vinyl Ketones, Allyl / Vinyl Nitriles, Allyl / Vinyl Sulfones, Allyl / Vinyl Thiocarbamates, Alkoxysilanes, Amides , Anilines - Aromatic Amines, Anilines, Amino (meta), Anilines, Amino (ortho) , Anilines, Amino (para) , Azides, Aziridines, Azonitriles, Baseline Toxicity Equations, Benzodioxoles, Benzothiazoles, Benzotriazoles, Benzoylcyclohexanediones, Benzyl Alcohols, Benzyl Amines, Benzyl Halides, Benzyl Imides, Benzyl Ketones, Benzyl Nitriles, Benzyl Thiols, , Bromoalkanes, Caprolactams, Carbamate Esters, Carbamate Esters, Oximes, Diazoniums, Diazoniums, Aromatic, Diketones, Dinitroanilines - Dinitroaromatic Amines, Dinitrobenzenes, Dinitrophenols, Dyes, Cationic, Epoxides, Mono, Epoxides, Mono Acid Substituted, Epoxides, Poly, Epoxides, Halo, Esters, Esters, Dithiophosphates, Esters, Monothiophosphates, Esters, Phosphate, Esters, Phosphinate, Esters, Halo, Esters, Nitriles, Esters, Peroxy, Esters x 10, Haloacetamides, Haloalcohols, Haloamines, Halo Benzamides, Halo Epoxides, Halo Esters, Halo Ethers, Halo Hydantoins, Halo Ketones, Halo Nitriles, Halo Pyridines, Hydrazines, Hydrazines, Semicarbazide, Alkyl Substituted, Hydrazines, Semicarbazide, Aryl, Meta/Para Substituted, Hydrazines, Semicarbazide, Aryl, Ortho Substituted, Hydroquinones / Quinones, Imidazoles, Imides, Imide Acids, Isocyanates, Isothiazolones, Ketone Alcohols, Malononitriles, Melamines, Mercaptans, Methacrylates, Neutral Organics, Nitriles, alpha OH, Nitriles, Esters, Nitriles, Polyaliphatic, Nitro alcohols, Nitro-/Nitrosobenzamides, Oxetanes, Peroxy Acids / Peroxides, Peroxy esters, Phenols, Phenols, Amines, Phenols, Poly, Phosphine Oxide, Phthalonitriles, Propargyl Alcohols, Propargyl Alcohols (Hindered) , Propargyl Amines, Propargyl Carbamates, Propargyl Ethers, Propargyl Halides, Pyrazoles, Pyrroles, Pyrethroids, Pyridines, alpha-Acid, Pyridine Thiones, Quinones / Hydroquinones, Rosins, Salicylates, Salicylic Acid, Schiff Bases, Silamines, Silanes (alkoxy) , Sulfonyl Ureas, Thiazolidinones, Thiazolidinones, Acid, Thiocarbamates, Di (Free Acid), Thiocarbamates, Di (Substituted), Thiocarbamates, Di (Fe salts), Thiocarbamates, Di (Mn salts), Thiocarbamates, Di (Na salts), Thiocarbamates, Di (Zn salts), Thiocarbamates, Mono, Thiocyanates, Thiols, Thiomethacrylates, Thiophenes, Thiotetrazoles, Thioureas, Triazines, Triazole Pyrimidines, Triazoles, Ureas, Substituted, Vinyl / Allyl Alcohols, Vinyl / Allyl Aldehyes, Vinyl / Allyl Amines, Vinyl / Allyl Esters, Vinyl / Allyl Ethers, Vinyl / Allyl Ether Amines, Vinyl / Allyl Halides, Vinyl / Allyl Ketones, Vinyl / Allyl Nitriles, Vinyl / Allyl Sulfones, Vinyl / Allyl Thiocarbamates. All chemical structures and functional groups of the substance are hence contained in the available chemical groups of the model.

6. ADEQUACY OF THE RESULT
The training set consist of data gained from testing under OPPTS guidelines for aquatic toxicity testing, which are equivalent to the respective OECD guidelines or EU methods, which are recommended as testing guidelines for testing with the purpose for classification and labelling, or risk assesment under REACH. 2-Pyridinecarboxaldehyde falls into the applicability domain of the model providing accurate results. Hence, the present prediction fits the purpose of classification and labelling and/or risk assessment.

Data source

Reference

Reference Type:

other: software application

Title:

ECOSAR (ECOlogical Structure Activity Relationship) Class Programm for Microsoft Windows , U. S. Environmental Protection Agency ; ECOSAR™ Version 1.11 [2012]

Author:

U.S. Environmental Protection Agency 1200 Pennsylvania Ave., N.W. (Mail Code 7406M) Washington, DC 20460

Year:

2013

Bibliographic source:

http://www.epa.gov/oppt/newchems/tools/21ecosar.htm

Materials and methods

Test guideline

Guideline:

other: REACH guidance on QSARs Chapter R.6 , May 2008

Principles of method if other than guideline:

The estimation for short-term toxicity to green algae of the test material was performed with US-EPA software ECOSAR v1.11. ECOSAR is currently programmed to identify over 120 chemical classes. For those classes, there are a more than 600 QSARs based on publicly available experimental data and confidential studies collected under the EPA New Chemicals Program. For each class, a standard EPA New Chemicals Program aquatic toxicity profile will be created using available QSARs and/or alternate QSAR approaches and professional judgment.

GLP compliance:

no

Remarks:

(not applicable)

Test material

Test material information

Constituent 1

Reference substance name:

Pyridine-2-carbaldehyde

EC Number:

214-333-6

EC Name:

Pyridine-2-carbaldehyde

Cas Number:

1121-60-4

Molecular formula:

C6H5NO

IUPAC Name:

pyridine-2-carbaldehyde

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report) : 2-Pyridinecarboxaldehyde ; (Pyridin-2-aldehyd)
- SMILES : O=Cc(nccc1)c1

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material:
Not applicable

Sampling and analysis

Details on sampling:

Not applicable

Test solutions

Details on test solutions:

Not applicable

Test organisms

Test organisms (species):

other: Green algae, not further specified

Details on test organisms:

No details available.

Study design

Test type:

other: QSAR estimation

Water media type:

not specified

Total exposure duration:

96 h

Post exposure observation period:

Not applicable

Test conditions

Hardness:

No details available.

Test temperature:

No details available

pH:

No details available

Dissolved oxygen:

No details available

Salinity:

No details available

Nominal and measured concentrations:

No details available

Details on test conditions:

No details available

Reference substance (positive control):

not required

Remarks:

(not applicable)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

100.831 mg/L

Remarks on result:

other: calculated value ECOSAR Class : Aldehydes (Mono)

Remarks:

based on exp. log Pow of 0.714 and calc. water solubility of 50240 mg/L

Effect concentrations 2

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

289.008 mg/L

Remarks on result:

other: calculated value ECOSAR Class : Neutral Organic SAR (Baseline Toxicity)

Remarks:

based on exp. log Pow of 0.714 and calc. water solubility of 50240 mg/L

Details on results:

No details available

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

(Scientifically accepted calculation method.)

Conclusions:

The study report describes a scientifically accepted calculation method for the prediction of short-term toxicity to green algae using the US-EPA software ECOSAR v1.11. No GLP criteria are applicable for the usage of this tool and the QSAR estimation is easily repeatable. The substance falls within the applicability domain of the QSAR model, hence, the result can be considered as reliable. The result is adequate for the regulatory purpose.The most sensitive species is fish, see IUCLID section 6.1.1 (exp.) for information on classification.

Executive summary:

The prediction for short-term toxicity to green algae of the test substance was determined by the computer program ECOSAR v1.11 by US-EPA .ECOSAR is currently programmed to identify over 120 chemical classes. For those classes, there are a more than 600 QSARs based on publicly available experimental data and confidential studies collected under the EPA New Chemicals Program. For each class, a standard EPA New Chemicals Program aquatic toxicity profile will be created using available QSARs and/or alternate QSAR approaches and professional judgment.

The Prediction for ECOSAR Class Aldehydes (Mono) resulting in a value for green algae EC50(96h) of 100.831 mg/L ( based on exp. log Pow of 0.714 and calc. water solubility of 50240 mg/L).

The predicted value for green algae EC50(96h) of 289.008 mg/L use the Neutral Organics QSAR equations which represent baseline toxicity potential (minimum toxicity) assuming a simple non-polar narcosis model.

Adequacy of the QSAR:

- QSAR model is scientifically valid.

- The substance falls within the applicability domain of the QSAR model.

- The prediction is fit for regulatory purpose.