p-tolyl acetate

Endpoint summary

Description of key information

Short-term toxicity to fish

A study was predicted using OECD QSAR toolbox version 3.3 (2017); to assess the toxicity effect of p-tolyl acetate on fish in a 96 hours of exposure. The median lethal concentration (LC50) for the test substance, p-tolyl acetate, in Danio rerio on the basis of mortality effect was estimated to be 122.09 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 p-tolyl acetate (CAS no. 140-39-6) does not exhibit short term toxicity to fish.

Short term toxicity to aquatic invertebrates

The median effective concentration (EC50) for the test substance,p-tolyl acetate, in Daphnia magna was determined to be 31.2 mg/L for immobilisation effects with 95% CI of 22.2 to 43.7 mg/L.But the BCF value of p-tolyl acetate was not >= 500 as well as the substance was found to be readily bio-degradable in water compartment. Thus, according to CLP Criteria for aquatic classification of the substance, it is concluded that p-tolyl acetate (CAS no. 140-39-6) does not exhibit short term toxicity to aquatic invertebrate.

Toxicity to aquatic algae and cyanobacteria

The median effective concentration (EC50) for the test substance, p-tolyl acetate, in a freshwater algae Desmodesmus subspicatus was determined to be 115.1 mg/L on the basis of effects on growth rate in a 72 hour study with 95% CL of 100.2 - 132.3 mg/L. Thus, according to CLP Criteria for aquatic classification of the substance, it is concluded that p-tolyl acetate (CAS No.- 140-39-6) does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

Toxicity to microorganisms

A study was predicted using OECD QSAR toolbox version 3.4(2017), to assess the toxicity effect of p-tolyl acetate in microorganism (tetrahymena pyriformis) in a 48 hours of exposure. The inhibition growth concentration (IGC50) value of p-tolyl acetate in microorganism (Tetrahymena pyriformis) on the basis of growth inhibition effect was estimated to be 1102.99 mg/L. Thus, it can be concluded that the test substance p-tolyl acetate (CAS No. 140 -39 -6) does not exhibit any toxicity effect to microorganism.

Additional information

Short-term toxicity to fish

Various studies including experimental data and predicted results from validated model for toxicity to fish with the target substance p-tolyl acetate (CAS No.140-39-6) and to its read across substance methyl acetate (Cas no. 79-20-9) by considering its structure-activity relationships, were summarized as follows:

 

A study was predicted using OECD QSAR toolbox version 3.3 (2017); to assess the toxicity effect of p-tolyl acetate on fish in a 96 hours of exposure. The median lethal concentration (LC50) for the test substance, p-tolyl acetate, in Danio rerio on the basis of mortality effect was estimated to be 122.09 mg/L.

 

Also, based on the Ecological Structure Activity Relationships (ECOSAR) Predictive Model version 1.11(2017), the median lethal concentration (LC50) for the test substance, p-tolyl acetate, in fish was estimated to be 92.914 mg/L on the basis of mortality effect in a 96 hour study.  But the BCF value of p-tolyl acetate was not >= 500 as well as the substance was found to be readily bio-degradable in water compartment. 

 

Experimental result (United States department of the interior fish and wildlife service; March 1957) for target chemical p-tolyl acetate (140-39-6) indicate that the short term toxicity test was performed on fish Petromyzon marinus at 5 mg/l concentration for 24 hrs. The fish was treated and maintained in good laboratory conditions. The pH was at 7.5-8.2 and temperature was maintained at 20 degree C.After experiment it was noted that the no mortality was observed thus no observed effect concentration (NOEC) for short term toxicity to fish Petromyzon marinus,Salmo gairdnerii and Lepomis macrochious for p-tolyl acetate (CAS No.-140-39-6) was consider to be NOEC at 5 mg/l concentration.

 

Another data from experimental study (Center for Lake Superior Environmental Studies, University of Wisconsin, Superior, WI:326 p.; 1985) for read across chemical Methyl acetate (Cas no. 79-20-9) indicates that in preliminary assessment of acute fish toxicity of test substance Methyl acetate was conducted in a static freshwater system for 96 hrs. on fish species Pimephales promelas of 32 days age with 18.6 MM length and 0.103 G weight. The test concentrations used for the study was 0, 439, 548, 685, 857 and 1070 mg/l. During experiment the gas liquid chromatography was used for analytical detection. For data analysis the LC50 with corresponding 95% confidence intervals were calculated using the corrected average of analyzed tank concentration and the Trimmed Spearman-Karber Method used. On the basis of behaviour effect the lethal concentration for test substance methyl acetate was found to be 399 mg/l.

 

In an additional experimental study (ECOTOX database;2017) for same read across substance i.e methyl acetate (Cas no. 79-20-9) on fish Pimephales promelas was carried out for 24 hr, the lethal concentration i.e LC50 was noted to be 96 h LC50 = 320 mg/L on the basis of mortality effect in static freshwater study condition.

 

So, based on the above predicted and experimental studies for substancep-tolyl acetate(CASNo. 140-39-6) and to its read across substancemethyl acetate (CAS No. 79-20-9), the lethal concentration (LC50) was found to be in the range of92.914mg/L to399mg/L andNOECvalue to be 5 mg/L.Based on the LC50 value the substance may classify for aquatic classification, but the BCF value of p-tolyl acetate was not >= 500 as well as the substance was found to be readily bio-degradable in water compartment. Thus, according to CLP Criteria for aquatic classification of the substance, it is concluded that p-tolyl acetate (CAS no. 140-39-6) does not exhibit short term toxicity to fish.

Short term toxicity to aquatic invertebrates

Various experimental studies following OECD guideline and predicted results from validated model for toxicity to aquatic invertebrate with the target substance p-tolyl acetate (CAS No. 140-39-6) and the relevant read across substances 2-acetoxybenzoic acid (CAS No.-50-78-2) and 3-methylbutyl 2-hydroxypropanoate (CAS No.-19329-89-6) by considering its structure-activity relationships, were summarized as follows:

 

Determination of the inhibition of the mobility of Daphnids was carried out with the substance p-tolyl acetate according to OECD Guideline 202.

The stock solution 100.0 mg/L was prepared by dissolving colourless liquid in reconstituted water. The test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted water. The test substance was tested at the concentrations 0, 6.0, 12.0, 24.0, 50.0, and 100.0 mg/L. The test was performed under static conditions in a fresh water system at a temperature of 20 °C± 1 °C. EC50 was calculated using non linear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance, p-tolyl acetate, in Daphnia magna was determined to be 31.2 mg/L for immobilisation effects with 95% CI of 22.2 to 43.7 mg/L. But the BCF value of p-tolyl acetate was not >= 500 as well as the substance was found to be readily bio-degradable in water compartment. Thus, according to CLP Criteria for aquatic classification of the substance, it is concluded that p-tolyl acetate (CAS no. 140-39-6) does not exhibit short term toxicity to aquatic invertebrate.

 

Also, based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, the short term toxicity to aquatic invertebrates was predicted for p-tolyl acetate (CAS No.140-39-6). EC50 value was estimated to be 106.27mg/L on the basis of intoxication effect for Daphnia magna for 48 hrs of duration.

Thus, it can be concluded that the p-tolyl acetate (CAS No.140-39-6) was considered to be not classified to aquatic invertebrates as per the CLP regulations. 

 

Similary, based on the Ecological Structure Activity Relationships (ECOSAR) Predictive Model version 1.11(2017), the median lethal concentration (LC50) for the test substance, p-tolyl acetate, in daphnia magna was estimated to be 53.43 mg/L on the basis of mortality effect in a 48 hour study. Based on this LC50 value the substance may qualify for aquatic classification but after compairing with CLP criteria it was found that the BCF value of p-tolyl acetate was not >= 500 as well as the substance was found to be readily bio-degradable in water compartment. Thus, according to CLP Criteria for aquatic classification of the substance, it is concluded that p-tolyl acetate (CAS no. 140-39-6) does not exhibit short term toxicity to aquatic invertebrate.

 

In another study of read across substances 2-acetoxybenzoic acid (50-78-2) which has 50-60% structural similarity, Daphnia tests were conducted following the European Guideline (Commission of the European Communities,1992) using the water flea D. magna. Daphnids were bred in ADaM, a culture medium imitating natural freshwater. Test was performed in 20 degree C with photoperiods of 16 h light/8 h dark. Young daphnids were used in 50 ml of culture each treatment was subdivided in four replicates, each containing 5 daphnia and observed for 24 and 48 hrs. After the experiment the EC 50 value for short term toxicity to aquatic invertebrates for 2-acetoxybenzoic acid (50-78-2) was determined to be 88.1 mg/l. As 2-acetoxybenzoic acid was determined to be readily biodegradable in nature hence, 2-acetoxybenzoic acid (50-78-2) was considered to be not classified as per the CLP regulations.

 

Another experimental study of read across substance 3-methylbutyl 2-hydroxypropanoate (19329-89-6) to aquatic invertebrates was performed by (Ecotox database, U.S Environmental Protection agency, 2017) for 48 hrs in fresh water. The concentration ranges from 168 – 232 mg/l. After the experiment the EC 50 value of 3-methylbutyl 2-hydroxypropanoate (19329-89-6) for Short term toxicity to aquatic invertebrates was determined to be 193 mg/l. Based on the result, the 3-methylbutyl 2-hydroxypropanoate (19329-89-6) was considered to be non-toxic to aquatic invertebrate and can be considered to not classified as per CLP regulation.

 

From the results of p-tolyl acetate (CAS No.140-39-6) and result of read across substances 2-acetoxybenzoic acid (50-78-2) and 3-methylbutyl 2-hydroxypropanoate (19329-89-6), as all the above weight of evidences supported the classifications, hence it can be considered that the p-tolyl acetate (CAS No.140-39-6) to be not classified as per the CLP regulations.

Toxicity to aquatic algae and cyanobacteria

Various studies including experimental data following OECD guideline and predicted results from validated model for toxicity to aquatic algae with the target substance p-tolyl acetate (CAS No.140-39-6) and to its read across substance tert-Butyl acetate (CAS no. 540-88-5) by considering its structure-activity relationships, were summarized as follows:

The freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance p-tolyl acetate (CAS No.- 140-39-6) according to OECD Guideline 201.

The stock solution 150.0 mg/L was prepared by dissolving colourless liquid in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and tested at the concentrations 0, 0, 30.0, 45.0, 67.5, 100.0, 150.0 mg/L. Effects on the growth rate of the organism were studied. The test was performed under static conditions in a static fresh water system at a temperature of 23± 2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter. ErC50 was calculated using non-linear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance, p-tolyl acetate, in a freshwater algae Desmodesmus subspicatus was determined to be 115.1 mg/L on the basis of effects on growth rate in a 72 hour study with 95% CL of 100.2 - 132.3 mg/L. Thus, according to CLP Criteria for aquatic classification of the substance, it is concluded that p-tolyl acetate (CAS No.- 140-39-6) does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

Also, based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, the short term toxicity on aquatic algae and cyanobacteria was predicted for target substance p-tolyl acetate (CAS no. 140 -39 -6) (2017). EC50 value was estimated to be127.536 mg/l for Pseudokirchneriella subcapitata for 72 h duration. Based on this value it can be concluded that the substance p-tolyl acetate can be considered as non-toxic to aquatic environment and thus can be considered to be not-classified as per the CLP classification criteria.

Additional supporting study for the short term toxicity on aquatic algae and cyanobacteria of target chemical p-tolyl acetate(CAS No. 140-39-6) is predicted using the EPI Suite ECOSAR version 1.10 (EPI Suite, 2017), the 96 hours EC50 was estimated to be 41.938 mg/l on green algae for substance p-tolyl acetate(CAS no. 140 -39 -6) with growth inhibition effects. But the BCF value of p-tolyl acetatewas not >= 500 as well as the substance was found to be readily bio-degradable in water compartment. Thus, the chemical p-tolyl acetate can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

In another study of read across substance tert-Butyl acetate (CAS no. 540-88-5) from peer reviewed journal (G. BRINGMANN and R. KOH, 1980), short term toxicity to Entosiphon Sulcatum study was carried out for 72 hrs. The study was based on the effects on Entosiphon Sulcatum in a static fresh water system. Test chemical of known concentration was prepared in sterile double distilled water. For maintenance of the test strain of Entosiphon sulcatum, continuously inoculate the expected required number of stock cultures at 72 h or 96 h intervals. For this, mix 8 ml of stock solution and 8 ml of sterile double-distilled water in 300 -ml Erlenmeyer flasks stoppered with metal caps and add 2 ml of a stock culture and 2 ml of the adjusted bacterial suspension for Entosiphon stock cultures. Store stock cultures at 25°C. Before inoculation control the flasks containing the stock cultures by means of an inverse microscope. Escherichia coli was used as a feeding material of the test organism Entosiphon sulcatum.

Prepare two parallel dilution series in 300 -ml Erlenmeyer flasks stoppered with metal caps. The dilutions will contain 1 part v/v each of pollutant solution in 20 to 214 parts v/v of mixture. Test vessel contain the known conc. of chemical and test organism. Leave the test culture at 25ᵒC for 72 hrs. Before measurement, control each flask by means of an inverse microscope. Add 10% of a 1.1% NaNO3 solution in double-distilled water filtered through a membrane filter (pore size 0.2/µm), and determine the number of protozoa by means of a cell counter. Pollutant concentrations at which the onset of inhibitory action was observed have been obtained by mathematical evaluation of counts. The term counts corresponds to impulses indicated by the coulter counter. Based on the onset of the inhibitory effect on population of the test organism Entosiphon Sulcatum, the 72 hr LOEC value was determined to be 970 mg/l, respectively.

 

Based on the overall reported results for target chemical p-tolyl acetate and for its read across substance, it can be concluded that the test substance p-tolyl acetate can be considered as non-toxic to aquatic algae and thus cannot be classified as hazardous as per the CLP classification criteria.

Toxicity to microorganisms

Two weight of evidence data were summaries for toxicity to micro organism with one predicted data for  target chemical p-tolyl acetate (CAS no.140-39-6) and one experimental study of read across Phenyl acetate (122-79-2).

For target chemical, a study was predicted using OECD QSAR toolbox version 3.4(2017), to assess the toxicity effect of p-tolyl acetate in microorganism (tetrahymena pyriformis) in a 48 hours of exposure. The inhibition growth concentration (IGC50) value of p-tolyl acetate in microorganism (Tetrahymena pyriformis) on the basis of growth inhibition effect was estimated to be 1102.99 mg/L. Thus, it can be concluded that the test substance p-tolyl acetate (CAS No. 140 -39 -6) does not exhibit any toxicity effect to microorganism.

 

Other evidence from read across Phenyl acetate (Cas no. 122-79-2) experimental study which indicate that the toxicity study for micro organism Uronema parduczi (Ciliate) was conduct for exposure period of 20 hrs. The effect concentration was observed to be 17 mg/l on the basis of population effect. (ECOTOX database; 2017)

 

Thus, based on the above weight of evidences it can be considered that p-tolyl acetate (CAS no.140-39-6) may have no concern for micro organism toxicity.