2-hydroxy-p-toluic acid

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 QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

other: Estimated data

Version / remarks:

No data available

Deviations:

not specified

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-hydroxy-p-toluic acid (m cresotic acid)
Molecular formula :C8H8O3
Molecular weight :152.148 g/mol
Smiles notation :Cc1ccc(c(c1)O)C(=O)O
InChl :1S/C8H8O3/c1-5-2-3-6(8(10)11)7(9)4-5/h2-4,9H,1H3,(H,10,11)
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:

No data available

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Remarks on exposure duration:

No data available

Post exposure observation period:

No data available

Hardness:

No data available

Test temperature:

20°C

pH:

No data available

Dissolved oxygen:

No data available

Salinity:

No data available

Conductivity:

No data available

Nominal and measured concentrations:

No data available

Details on test conditions:

No data available

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

164.709 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

other: Intoxication

Remarks on result:

other: Estimated data

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 5 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 ( not "i") )  )  and ("j" and ( not "k") )  )  and "l" )  and ("m" and ( not "n") )  )  and ("o" and "p" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as m,p - Cresols by OECD HPV Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Phenols (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "c"

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

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Class 2 (less inert compounds) by Acute aquatic toxicity classification by Verhaar (Modified)

Domain logical expression index: "e"

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

Domain logical expression index: "f"

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

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Moderate binder, NH2 group OR Moderate binder, OH grooup OR Non binder, impaired OH or NH2 group OR Non binder, MW>500 OR Non binder, non cyclic structure OR Non binder, without OH or NH2 group OR Strong binder, NH2 group OR Strong binder, OH group OR Very strong binder, OH group OR Weak binder, NH2 group by Estrogen Receptor Binding

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Alkyl substituent on aromatic ring AND Aromatic acid   [-C(=O)-OH] AND Aromatic alcohol  [-OH] AND Aromatic-CH3 AND Aromatic-H AND Benzene by Bioaccumulation - metabolism alerts

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Aldehyde   [-CHO] OR Aliphatic alcohol  [-OH] OR Amide   [-C(=O)-N  or -C(=S)-N] OR Aromatic amine   [-NH2  or  -NH-] OR Aromatic chloride   [-CL] OR Aromatic ether  [-O-aromatic carbon] OR Aromatic nitro  [-NO2] OR Aromatic-CH2 OR -C=CH  [alkenyl hydrogen] OR Carbon with 4 single bonds & no hydrogens OR -CH -  [cyclic] OR -CH2-  [cyclic] OR -CH2-  [linear] OR Cyanide / Nitriles   [-C#N] OR Ester   [-C(=O)-O-C] OR Fluorine  [-F] OR Ketone   [-C-C(=O)-C-] OR Linear C4 terminal chain  [CCC-CH3] OR Methyl  [-CH3] OR Naphthalene OR Number of fused 6-carbon aromatic rings OR Number of fused acyclic rings OR Trifluoromethyl group   [-CF3] OR Unsubstituted phenyl group (C6H5-) OR Urea   [N-C(=O)-N] by Bioaccumulation - metabolism alerts

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Alkyl arenes AND Aryl AND Carboxylic acid AND Phenol by Organic Functional groups

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "l"

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

Domain logical expression index: "m"

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

Domain logical expression index: "n"

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

Domain logical expression index: "o"

Parametric boundary:The target chemical should have a value of log Kow which is >= 1.39

Domain logical expression index: "p"

Parametric boundary:The target chemical should have a value of log Kow which is <= 3.15

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 value was estimated to be 164.708 mg/l when 2-hydroxy-p-toluic acid (m cresotic acid) 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 for2-hydroxy-p-toluic acid (m cresotic acid) (50-85-1).The EC50 value was estimated to be 164.708 mg/l when 2-hydroxy-p-toluic acid (m cresotic acid)exposed to Daphnia magna for 48hrs.

Based on the EC50 it was concluded that the m-cresotic acid was not toxic and can be consider as not classified as per the CLP classification criteria.

Description of key information

Short-term toxicity to aquatic invertebrates :

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 for2-hydroxy-p-toluic acid (m cresotic acid) (50-85-1).The EC50 value was estimated to be 164.708 mg/l when 2-hydroxy-p-toluic acid (m cresotic acid)exposed to Daphnia magna for 48hrs.

Based on the EC50 it was concluded that the m-cresotic acid was not toxic and can be consider as not classified as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

164.708 mg/L

Additional information

Short-term toxicity to aquatic invertebrates :

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-hydroxy-p-toluic acid (m cresotic acid) (50-85-1).The EC50 value was estimated to be 164.708 mg/l when 2-hydroxy-p-toluic acid (m cresotic acid)exposed to Daphnia magna for 48hrs.

Based on the EC50 it was concluded that the m-cresotic acid was not toxic and can be consider as not classified as per the CLP classification criteria.

The above prediction was suppported by another prediction for the target . Based on the average value of both models ( Leadscope Enterprise model and SciMatics SciQSAR model), the result were predicted in Battery model. Based on the Danish (Q)SAR Database, the 48 hours EC50 was estimated to be 216.1135 mg/l on Daphnia Magna for substance m-cresotic acid with immobilization effects. Thus based on this value it can be concluded that the substance can not be classified as per the criteria of CLP regulation.

The above predictions were supported by experimental study conducted by Wang, W.H., and J.P. Lay summarized in Ecotoxicology and Environmental Safety  Volume 17, Issue 3, June 1989, Pages 308–316 for structurally similar read across substance Sodium salicylate (CAS:54 -21 -7).

Short term toxicity of sodium salicylate on the growth of daphnia magna was carried out for 24hrs. The effective concentration EC0and EC10 value of sodium salicylate in Daphnia magna in a 24 hr study on mortality effect was 80mg/l and 304 mg/L.Thus based on the immolization by consedring EC value for aquatic classification of the substance , it is concluded that sodium salicylate does not exhibit short term toxicity to aquatic invertebrate (Daphnia magna).

Another experimental data summarized in Sewage Works Journal Vol. 18, No. 1 (Jan., 1946), pp. 82-87 for structurally similar read across substance Sodium salicylate (CAS:54 -21 -7) .

Lethal Threshold Concentration value of Sodium salicylate in Daphnia magna in a 48 hr study on intoxication effect was found to be 1450 mg/L.Thus,considering the CLP Criteria for aquatic classification of the substance , it is concluded that Sodium salicylate does not exhibit short term toxicity to aquatic invertebrate (Daphnia magna) .

The above experimental data was further supported by experimental data summarized in Chemosphere 59 (2005) 255–261 for structurally similar read substance Benzoic acid (CAS: 65 -85 -0).

Short term toxicity to aquatic invertebrates was performed in Daphnia magna for 48 hrs. The young daphnids were obtained from continuous cultures in 1 liter glass beakers at 21 ± 0.3 degree C, in dechlorinated and conditioned tap water, the medium was renewed in three weeks and daphnids were fed daily with the green alga Selenastrum capricornutum. The pH of test solution was adjusted to 7.45 ± 0.05 with HCL and NaOH. The concentrations of the resultant solutions were checked before and after (48 h) exposure using a UV–visible spectrophotometer.

As the experiment starts neonate were placed in 50 ml of beaker with 40 ml of test solution. All experiment was made in four replicates and performed at 21 ± 0.3 degree C under 16 h light: 8 h dark photoperiod. Immobility was observed after 24 and 48 hrs and EC 50 value was calculated.

After the experiment the EC 50 value of Benzoic acid (65-85-0) for Daphnia magna was determined to be 860 mg/l in 48 hrs.

Another structurally similar read across substance Salicylic acid (CAS: 69 -72 -7) was used to support the above experimental data .

Short term toxicity study to Daphnia magnaby using chemicalsalicylic acid was carried out for 48hrs. Static method was used and the age of daphnia magna was <24hrs. Based on the immobility of daphnia magna by using chemical salicylic acid, the EC50 value was 1147.57mg/l.

Based on the CLP regulation the 2-hydroxy-p-toluic acid (m cresotic acid) (50-85 -1) is considered to be not toxic to aquatic invertebrates and can be concluded to be not classified