Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The predicted data suggests the effective concentration (EC50) for the test compound PyrazoloneTwas estimated to be131.89mg/L on the basis of mortality. 

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
131.89 mg/L

Additional information

Various predicted data for chemical PyrazoloneTalong with its read across substance were reviewed to summarize the following information:

 

48 hrs aquatic toxicity study (SSS QSAR prediction model, 2016) was conducted to assess toxic effects of the test compound PyrazoloneT(CAS no 118-47-8) and the results were predicted. The study was based on the effects of the test compound on the Daphnia magna in a static fresh water system. The predicted data suggests the effective concentration (EC50) for the test compound PyrazoloneTwas estimated to be131.89mg/L on the basis of mortality. 

 

48 hrs aquatic toxicity study (EPI suite, 2016) was conducted to assess toxic effects of the test compound PyrazoloneT(CAS no 118-47-8) and the results were predicted. The study was based on the effects of the test compound on Daphnia magna in a static fresh water system. The predicted data suggests the effective concentration (EC50) for the test compound PyrazoloneTwas estimated to be 258000 mg/L. 

 

Estimated 48 hrs EC50 value of test substance Pyrazolone T on Daphnia magna was determined by three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database.

Based on mortality of test organism Daphnia magna, the estimated 48 hrs EC50 value by three different model i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database was found to be 299.506mg/l.

 

Short term toxicity study (M. St. J. Warne and A. D. Schifko, 1999) to cladoceranCeriodaphnia dubiawas carried out for 48 hrs. Stock solutions of test substance Tartrazine was made by dissolving the appropriate amount in 1 or 2 L of the Sydney mains water and then gently stirred for 12 h in the dark at 23±1°C using Teflon magnetic stirrers. Stirring was conducted so that no bubbles were formed when the test substance was dissolved, as the formation of bubbles leads to depletion of surfactants in the solution. Light was excluded during the stirring to minimize photodegradation of the chemicals. Stock solutions were diluted to the appropriate concentrations immediately prior to the commencement of a test. Test chemical was stored in the dark at 22±2°C.

 All neonates used in the toxicity tests were less than 24 h old.C. cf.dubiawere cultured and tested at 23±1°C in dechlorinated Sydney mains water which was filtered (1µm), aged (1 month), and adjusted to 500µS/cm with seawater. Cultures ofC. cf.dubiawere maintained in 2-L glass beakers and transferred to fresh water three times weekly. Food was provided after water renewal at a concentration of 25,000 cells/ml of each of the unicellular algaePseudokirchneriellia subcapitataPrintz (formerly namedSelenastrum capricornutum) andAnkistrodesmussp.

 Five cladocera were randomly allocated to each test beaker and each treatment in a test was triplicated. Beakers were then randomly positioned in constant temperature cabinets and maintained at 23±1°C with a 16 : 8-h light to dark regime and light intensity below 1000 lx at the surface of the solutions. Animals were not fed during the tests.The test was terminated after 48 hrs andthe number of immobile cladocera counted.Immobilization was defined as the absence of visible movement by the cladocera within 15 s of gentle agitation of the test solution.

 The 48-h EC50 (immobilization) values and 95% confidence intervals were based on nominal concentrations and were determined by the trimmed Spearman-Karber method.Based on immobilization of the test organism, the EC50 value was found to be 5706.55mg/l.

Short term toxicity study (Noriko KOBAYASHI, Naeyuki TANIGUCHI, Fumiyo SAK0 and Eimatsu TAKAKUWA, 1977) to Artemia Salina was carried out for 24-48 hrs. The test chemical conc. used for the study was 5343.68 mg/l and 534.368 mg/l, respectively. A. salina eggs (encysted dried gastrulae) were commercially obtained, and were stored at -20°C, Eggs used in experiments were washed and stored at room temperature in a desiccator over anhydrous granular CaCl,. Larvae were obtained by incubating eggs in petri dishes containing muslin-filtered sea water at 30°C for 24 hours. The larvae were separated from shells, dead larvae and unhatched eggs by their phototactic movements toward a light source.

Food dyes of various concentrations were placed in a petri dish, and sea water containing 20 to 30 larva ewas added. After this was incubated at 30°C for 24 hours and 48 hours, larvae surviving were measured by direct count. The same method was tested from 5 to 6 times for each concentration, and the death rate was calculated.

The study was performed under static conditions for 24 – 48 hrs at 30°C. Death was assumed to have occurred when there was no movement. The death rate was defined as the average of the percentage of deaths observed for 24 hours and 48 hours.

Based on death rate or mortality of test organism, the LC83.8 value was found to be 5343.68 mg/l.

 

On the basis of results of various predictions and read across, the chemicalPyrazoloneT can be considered as not likely to be toxic to aquatic invertebrates at environmentally relevant concentrations and can be classified as non- hazardous as per the criteria of CLP regulation.