p-hydroxyphenylacetic acid

Short-term toxicity to fish

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 closest read across substances, the toxicity to aquatic fish was predicted 4-Hydroxyphenylacetic Acid (CAS: 156-38-7). LC50 mortality value was estimated to be 135.153 mg/l for Danio rerio for 96.0 hrs duration. It was concluded that 4-Hydroxyphenylacetic Acid (CAS: 156-38-7) was likely to be not toxic to aquatic fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

135.153 mg/L

Additional information

Following studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 4-Hydroxyphenylacetic Acid (CAS: 156-38-7). towards fish is summarized as follows:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity to aquatic fish was predicted 4-Hydroxyphenylacetic Acid (CAS: 156-38-7). LC50 mortality value was estimated to be 135.153 mg/l for Danio rerio for 96.0 hrs duration. It was concluded that 4-Hydroxyphenylacetic Acid (CAS: 156-38-7) was likely to be not toxic to aquatic fish.

The above prediction for the target chemical done using the OECD QSAR toolbox version 3.3 suggests that 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 1100.263 mg/l for 4-Hydroxyphenylacetic Acid in 96 hrs.

Based on this value it can be concluded that the 4-Hydroxyphenylacetic Acid is considered to be not toxic to aquatic environment and can be "not classified " category as per the criteria mentioned in CLP regulation.

Similar Prediction done using average value of both models i.e Leadscope and SciMatics SciQSAR model and the result were predicted in Battery model. Based on the Danish (Q)SAR Database, the 96hours LC50 was estimated to be 286.0272 mg/L on Pimephales promelas for 4-Hydroxyphenylacetic Acid (CAS: 156-38-7) with mortality effects. Thus based on this value it can be concluded that the 4-Hydroxyphenylacetic Acid (CAS: 156-38-7) can be "not classified" per the criteria of CLP regulation.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across 4-methoxyphenylacetic acid (CAS No. 104-01-8) from the UERL Lab report 2017, suggests that the Fish Acute Toxicity test according to OECD Guideline 203 was conducted for 4-methoxyphenylacetic acid. The nominal concentration selected for the experiment were 100mg/L and test fish were exposed to these concentration for 96 hours. The median lethal concentration (LC50) for 4-methoxyphenylacetic acid on Danio rerio in a 96 hours study on the basis of mortality effect was found to be >100 mg/L. Thus, on the basis of this LC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance, 4-methoxyphenylacetic acid (CAS No. 104-01-8) does not exhibit short term toxicity to fish.

LC0 (96 hours) (highest loading at which no mortality was observed) = 100 mg/L

LC50 (96 hours) Experimental = >100 mg/L

Thus based on the effect concentrations which is in the range >100 mg/L to1100.263 mg/lgive the conclusion that test substance 4-Hydroxyphenylacetic Acid (CAS: 156-38-7) is likely to be not toxic to aquatic environment at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “not classified” as per the CLP classification criteria.