N-potassium phthalimide

Endpoint summary

Description of key information

Short-term toxicity to fish:

The short-term toxicity of Potassium phthalimide (CAS no. 1074-82-4)to fish is predicted using QSAR toolbox version. 3.3.The prediction is based on the effects observed in a static freshwater system during a 96 hr exposure. The lethal concentration (LC50) for the substance is estimated to be 151.66 mg/L. Thus, based on lethal concentration value, it can be concluded that the test chemical Potassium phthalimide can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

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 five closest read across substances, the short term toxicity on aquatic invertebrates was predicted for potassium 1,3-dioxo-1,3-dihydroisoindol-2-ide (CAS no 1074-82-4). EC50 value was estimated to be 161.00mg/L on the basis of mobility for Daphnia magna for 48 hrs duration. As the 1,3-dioxo-1,3-dihydroisoindol-2-ide (CAS no 1074-82-4) was considered being non hazardous to aquatic invertebrates and can be considered to be not classified as per the CLP regulations.

Toxicity to aquatic algae and cyanobacteria

The effect of test item N-potassium phthalimide, CAS No. 1074-82-4 was studied on the growth of fresh water green alga Chlorella vulgaris (UERL Study report, Sustainability Support Services (Europe) AB, Report no. 1074 -82 -4/01/2017/AT, 2017). The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 3.125 mg/L,6.25 mg/L,12.5 mg/L,25 mg/L,50 mg/L,100 mg/L. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 133.35 mg/L. Thus based on this value, it can be concluded that the substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP classification criteria.

 

Additional information

Short-term toxicity to fish:

Four studies including Predicted data and experimental results for short term fish toxicity endpoint of the target chemical Potassium phthalimide (CAS no. 1074-82-4) with relevant read across chemical which is close to target chemical using log Kow as a primary descriptor were reviewed to summarize the following information:

 

First study indicate the 96 hrs aquatic toxicity was predicted to assess toxic effects of the test compound Potassium phthalimide (CAS no. 1074-82-4) using OECD QSAR toolbox ver.3.3;2017. The prediction was based on the effects of the test compound on fish species Lepomis macrochirus in a static fresh water system. The data suggests the median lethal concentration (LC50) for the test compound Potassium phthalimide (CAS no. 1074-82-4) was estimated to be 151.66 mg/l on the basis of mortality effect.

 Whereas another prediction using the EPI Suite ECOSAR version 1.10 (EPI Suite, 2017), the 96 hours LC50 was estimated to be 1818.541 mg/l on fish for target substance Potassium phthalimide (CAS no. 1074-82-4) with mortality effects.

 

Above both aquatic classification supported by experimental data (Spec.Sci.Rep.Fish.No.207, Fish Wildl.Serv., U.S.D.I., Washington, DC:157 p.; 1957) indicate in short term fish toxicity study the test substance Potassium phthalimide (Cas no. 1074-82-4) exposed to fish species Petromyzon marinus (Sea Lamprey) for 24 hrs. During experiment the 12.77 deg.C (55 Fahrenheit) test temp., 7.5 to 8.2 pH and 8.6 to 13.7 dissolved oxygen was maintained throughout the study. And test concentration used as 0.1, 1.0 and 5.0 mg/l. No observable effects including mortality was observed on test species Petromyzon marinus (Sea Lamprey) for 24 hrs.Thus NOEL (no observed effect level) was consider to be 5 mg/l for test substance Potassium phthalimide (Cas no. 1074-82-4).

 

Last study from experimental data source for read across chemical 1-(4,6-dimethoxypyrimidin-2-yl)-3-[2-dimethylcarbamoyl)phenylsulfamoyl]urea (Cas no. 213464-77-8) suggest the short term fish toxicity study on test species Lepomis macrochirus (Bluegill)of test substance1-(4,6-dimethoxypyrimidin-2-yl)-3-[2-dimethylcarbamoyl)phenylsulfamoyl]urea was determine for exposure period 96 hrs.In the experiment static condition maintained.

On the basis of mortality effect the lethal concentration (LC50) on fish Lepomis macrochirus (Bluegill) was observed to be >142 mg/l.

From all four studies the median lethal concentration (LC50) observed in the range of >142 to 1818.541 mg/l for 96 hrs and NOEC was 5 mg/l for 24 hrs.exposure period.

Thus based on the available results, it can be concluded that the test substance Potassium phthalimide (CAS no. 1074-82-4) can be considered as non toxic to fish and thus not consider for the aquatic classification as per the CLP criteria.

Short term toxicity to aquatic invertebrates:

Short term toxicity to aquatic invertebrates for potassium 1,3-dioxo-1,3-dihydroisoindol-2-ide (CAS no 1074-82-4) was summaries with two estimated data for target and two experimental study with read across substances N-Methylphthalimide (550-44-7) which has 60-70 % structural similarity with target and N,N’–ethylenebis[N–acetylacetamide] (10543-57-4) which has functionally similar.

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances, the short term toxicity on aquatic invertebrates was predicted for potassium 1,3-dioxo-1,3-dihydroisoindol-2-ide (CAS no 1074-82-4). EC50 value was estimated to be 161.00mg/L on the basis of mobility for Daphnia magna for 48 hrs duration. As the 1,3-dioxo-1,3-dihydroisoindol-2-ide (CAS no 1074-82-4) was considered being non hazardous to aquatic invertebrates and can be considered to be not classified as per the CLP regulations.

Another prediction using EPI suite, ECOSAR version 1.1, 2017, based on the effects observed in 48 hr exposure. The lethal concentration (LC50) for the 1, 3-dioxo-1, 3-dihydroisoindol-2-ide (CAS no 1074-82-4) was estimated to be 1232.557 mg/l. Hence, 1, 3-dioxo-1, 3-dihydroisoindol-2-ide (CAS no 1074-82-4) was considered being non hazardous to aquatic invertebrates and can be considered to be not classified as per the CLP regulations. 

 

A study on read across chemical N-Methylphthalimide (550-44-7) which has 60-70 % structural similarity with target (201-14220 B, Robust summary, 30 December 2002), short term toxicity to aquatic invertebrates was performed in Daphnia magna for 24 hrs in static test condition. Nominal and measured test concentrations were used, in which the nominal concentration were used for test. The culture vessels were incubated in a temperature controlled room at 20 + 1ºC, under an 8-hour dark and 16-hour light photoperiod. The light intensity at the water surface was 400 to 800 lux. Daphnia in stock culture were fed with green alga and solution of yeast. At test initiation, dissolved oxygen, temperature, pH, and conductivity ranged from 8.3 to 9.1 mg/L, 19.5 to 20.7 ᵒC, 6.7 to 7.9 units, and 342 to 348 μS/cm respectively. At test termination, dissolved oxygen, temperature, and pH ranged from 8.3 to 9.1 mg/L, 19.5 to 20.7 ºC, and 7.0 to 7.7 units, respectively. General observations on behavior were made at test initiation, and at 30 minutes and 24 hours of exposure. Based on experimental result, the EC 50 value for 24 hrs of N-Methylphthalimide (550-44-7) was determined to be 112 mg/l. On the basis of result, the N-Methylphthalimide (550-44-7) was considered to be non- toxic to aquatic invertebrates and can be considered to be not classified as per the CLP regulations.

 Another study on N,N’–ethylenebis[N–acetylacetamide] (10543-57-4)toxicity to aquatic invertebrates was performed in daphnia magna for 24 and 48 hrs. The EC 50 value for Daphnia magna was determined to be >500 and >800 mg/l for N,N’–ethylenebis[N–acetylacetamide] (10543-57-4).Based on the value the N,N’–ethylenebis[N–acetylacetamide](10543-57-4) was considered to be non-toxic to aquatic invertebrates and can be considered to be non-classified as per the CLP regulations.

 On the basis of predicted results for toxicity to aquatic invertebrates from target and study from read across all weight of evidences has supported the classification hence it can be considered that 1,3-dioxo-1,3-dihydroisoindol-2-ide(CAS no 1074-82-4)was likely to be non-toxic to aquatic invertebrates at environmentally relevant concentrations and can be considered to be not classified as per the criteria of CLP regulation.

Toxicity to aquatic algae and cyanobacteria

For toxicity to aquatic algae and cyanobacteria endpoint, 1 experimental study which is supported by the 2 predicted data of target chemical Potassium phthalimide (CAS no. 1074 -82 -4), alongwith the study of its closest read across chemicals using log kow as the primary descriptor, the studies were reviewed to summarize the following information:

 

In an experimental key study report for target chemical N-potassium phthalimide, (CAS No. 1074-82-4), the effect of test item N-potassium phthalimide, CAS No. 1074-82-4 was studied on the growth of fresh water green alga Chlorella vulgaris (UERL Study report, Sustainability Support Services (Europe) AB, Report no. 1074 -82 -4/01/2017/AT, 2017). The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 3.125 mg/L,6.25 mg/L,12.5 mg/L,25 mg/L,50 mg/L,100 mg/L. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 133.35 mg/L. Thus based on this value, it can be concluded that the substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP classification criteria.

 

Short term toxicity on aquatic algae and cyanobacteria of target chemical Potassium phthalimide (CAS no. 1074 -82 -4), is predicted using the EPI Suite ECOSAR version 1.10 (2017). The 96 hours EC50 was estimated to be 413.131 mg/l on green algae for substance Potassium phthalimide (CAS no. 1074 -82 -4) with growth inhibition effects. Thus, based on this value, it can be concluded that the test chemical Potassium phthalimide can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

In a supporting study of read across chemical Phthalimide (CAS no. 85-41-6), short term toxicity to algae study was carried out for 72 hrs (J-CHECK, 2016). The study was based on the effects of the read across compound Phthalimide (CAS no. 85-41-6) on green algae in a static fresh water system. On the basis of effect on growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be > 150 and 1.1 mg/l and on the basis of areas under the growth curves, the 72 hr EC50 and NOEC value was determined to be 62 and 6.5 mg/l, respectively. Thus, based on the EC50 value (> 150 mg/l), it can be concluded that the read across substance Phthalimide can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

For read across chemical Phthalimide (CAS no. 85-41-6), short term toxicity to Selenastrum capricornutum study was carried out for 72 hrs (OECD SIDS, 2005). The study was performed according to OECD Guideline 201 (Alga, Growth Inhibition Test). The study was based on the effects of the read across compound Phthalimide (CAS no. 85-41-6) on Selenastrum capricornutum in a static fresh water system at an average temperature of 22.1°C. Test chemical conc. used for the study were0, 10.6, 19.1, 34.3, 61.7, 111.1 and 200.0 mg/l, respectively. 300 mL net triangle conical glass flask was used as a test vessel. The flasks were incubated in a shaking water bath at 22.1 degrees C with continuous illumination at 4000 - 5000 lux. Based on the effect on growth rate of the test organism Selenastrum capricornutum, the 72 hrs ExC50 and NOEC value was determined to be 161 and 10.7 mg/l, respectively. Thus, based on EC50 value, it can be concluded that the read across substance Phthalimide can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

In a supporting study of another read across chemical N-(Cyclohexylthio)phthalimide (CAS no. 17796-82-6), short term toxicity to Selenastrum capricornutum (green algae) study was carried out for 96 hrs (HSDB, 2016). The study was based on the effects of the read across compound N-(Cyclohexylthio)phthalimide (CAS no. 17796-82-6) on Selenastrum capricornutum (green algae) in a static fresh water system.The test algae were obtained from the US EPA Environmental Research Laboratory in Corvallis, Oregon. Test chemical conc. used for the study were 0, 6, 10, 32, 56 and 100 mg/l, respectively. Initial cell density of algae was 2 × 104cells/ml. All tests were carried out in triplicates. Statistical analysis involved converting each test concentration to a logarithm, and the corresponding percentage decrease of in vivo chlorophyll a or cell numbers was converted to a probit. The EC50 and 95% confidence limits were then calculated by linear regression. The toxicity of the test substance to algae was similar throughout the 96 hr exposure. There was no significant difference between growth of the control and solvent control cultures after 96 hr of exposure by either measured parameter. Based on effect on biomass and growth of the test organism Selenastrum capricornutum (green algae), the 96 hr EC50 value was determined to be 21 mg/l and on the basis of chlorophyll measurement, the 96 hr EC50 value was determined to be 22 mg/l and NOEC value was 6 mg/l, respectively. Thus, based on the EC50 value, it can be concluded that the read across substance N-(Cyclohexylthio)phthalimide can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.Since the chemical is readily biodegradable in nature, chemical N-(Cyclohexylthio)phthalimide can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

Based on the overall reported results of experimental data and various studies for target chemical and of its read across substance (from authoritative database and secondary source), it can be concluded that the test substance Potassium phthalimide can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.