2-hydroxy-p-toluic acid

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Estimated data generated using the EPI Suite program developed by the USEPA.

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

Prediction done using BCFBAF (v3.01) model

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 2-Hydroxy-4-methylbenzoic 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

Radiolabelling:

not specified

Vehicle:

not specified

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

not specified

Water / sediment media type:

natural water: freshwater

Test temperature:

25 deg.C

Reference substance (positive control):

not specified

Key result

Temp.:

25 °C

Type:

BCF

Value:

3.162 L/kg

Basis:

whole body w.w.

Calculation basis:

other: estimated

Remarks on result:

other: Non-bioaccumulative

BCFBAF Program (v3.01) Results:

==============================

SMILES : Cc1ccc(C(=O)(O))c(O)c1

CHEM : Benzoic acid, 2-hydroxy-4-methyl-

MOL FOR: C8 H8 O3

MOL WT : 152.15

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

Log BCF (regression-based estimate): 0.50 (BCF = 3.16 L/kg wet-wt)

Biotransformation Half-Life (days) : 0.0958 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 1.45 (BAF = 28.3 L/kg wet-wt)

Log Kow (experimental): 2.99

Log Kow used by BCF estimates: 2.99

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)

Validity criteria fulfilled:

not specified

Conclusions:

The bioconcentration factor (BCF) of 2-Hydroxy-4-methylbenzoic acid was estimated to be 3.162 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical 2-Hydroxy-4-methylbenzoic acid is not expected to bioaccumulate in the food chain.

Executive summary:

BCFBAF model (v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical 2-Hydroxy-4-methylbenzoic acid (CAS No. 50 -85 -1). The bioconcentration factor (BCF) of 2-Hydroxy-4-methylbenzoic acid was estimated to be 3.162 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical 2-Hydroxy-4-methylbenzoic acid is not expected to bioaccumulate in the food chain.

Description of key information

BCFBAF model (v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical 2-Hydroxy-4-methylbenzoic acid (CAS No. 50 -85 -1). The bioconcentration factor (BCF) of 2-Hydroxy-4-methylbenzoic acid was estimated to be 3.162 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical 2-Hydroxy-4-methylbenzoic acid is not expected to bioaccumulate in the food chain.

Key value for chemical safety assessment

BCF (aquatic species):

3.162 L/kg ww

Additional information

Different predicted data studies for the target compound 2-Hydroxy-4-methylbenzoic acid (CAS No. 50-85-1) and supporting experimental weight of evidence studies for its structurally similar read across substance were reviewed for the bioaccumulation end point and results of all the studies are summarized as below:

In a prediction done using the BCFBAF Program (v3.01) of Estimation Programs Interface (EPI Suite, 2017) the bioconcentration factor (BCF) of test chemical 2-Hydroxy-4-methylbenzoic acid (CAS No. 50 -85 -1) was estimated. The bioconcentration factor (BCF) of 2-Hydroxy-4-methylbenzoic acid was estimated to be 3.162 L/kg whole body w.w (at 25 deg C).

In an another prediction done by using Bio-concentration Factor (v12.1.0.50374) module ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017), the BCF over the entire pH scale of the test substance 2-Hydroxy-4-methylbenzoic acid was estimated to be 48.3, 46.3, 32.7, 8.32, 1.01 and approx. 1.0 at pH range 0, 1, 2, 3, 4 and 5-14, respectively.

In next study the Bioconcentration Factor (BCF) of test chemical 2-Hydroxy-4-methylbenzoic acid (CAS no. 50 -85 -1) was estimated using Chemspider database (ChemSpider, 2017) of Royal Society of chemistry (RCS, 2017). The bioconcentration factor of test substance 2-Hydroxy-4-methylbenzoic acid was estimated to be 1.00 at both pH 5.5 and 7.4, respectively.

Another predicted data was estimated using SciFinder database (American Chemical Society (ACS), 2017) was used for predicting the bioconcentration factor (BCF) of test chemical 2-Hydroxy-4-methylbenzoic acid (CAS No. 50 -85 -1). The bioconcentration factor (BCF) of 2-Hydroxy-4-methylbenzoic acid was estimated to be 38.0, 26.9, 6.83 and 1.0 at pH range 1, 2, 3 and 4-10, respectively, (at 25 deg C).

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the bioaccumulation i.e BCF for test substance 2-Hydroxy-4-methylbenzoic acid was estimated to be 3.99 dimensionless . The predicted BCF result was based on the 5 OECD principles. Thus based on the result it is concluded that the test substance 2-Hydroxy-4-methylbenzoic acid is non-bioaccumulative in nature.

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical 2-hydroxy benzoic acid (CAS no. 69-72-7), the bioaccumulation experiment was conducted for estimating the BCF (bioaccumulation factor) value of read across chemical 2-hydroxy benzoic acid. The bioaccumulation factor (BCF) value was calculated using a log Kow of 2.26 and a regression derived equation. The BCF (bioaccumulation factor) value 2 -hydroxy benzoic acid was determined to be 3 dimensionless.

Another supporting weight of evidence study was done from same source mentioned above for another read across chemical in this study BCF value was estimated to be 3 dimensionless for read across chemical O-acetylsalicylic acid, using a log Kow value of 1.19 and a regression-derived equation. This BCF suggests the potential for bioconcentration in aquatic organisms is low.

In next weight of evidence study from authoritative database HSDB, 2017 the BCF value was estimated to be 3 dimensionless for read across chemical phthalic acid , by using a log Kow of 0.73 and a regression-derived equation, this BCF suggests the potential for bioconcentration in aquatic organisms is negligible.

In last experimental study for read cross chemical Benzoic acid BCF value was determined on the basis of Accumulation effect the Bioconcentration factor (BCF) for read across substance Benzoic acid was observed to be 21 dimensionless for dose concentration 1.78 ug/L in fish Gambusia affinis (Western Mosquitofish) for exposure period of 24 hrs. Based on the result it is concluded that the read across substance is non bioaccumulative in nature.

On the basis of above results for target chemical 2-Hydroxy-4-methylbenzoic acid (from EPI suite, ACD labs, ChemSpider, SciFinder database and CompTox Chemistry Dashboard,  2017) and for its read across substance (from authoritative database HSDB, and Ecotox database 2017), it can be concluded that the BCF value of test substance 2-Hydroxy-4-methylbenzoic acid ranges from 1 to 48.3 dimensionless which does not exceed the bioconcentration threshold of 2000, indicating that the chemical 2-Hydroxy-4-methylbenzoic acid is not expected to bioaccumulate in the food chain.