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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

1) Key_Short-term toxicity to fish: LC50(96h) = 5621 mg/L (nominal) for Danio rerio (static, freshwater, EU Method C.1) (ongoing)

2) Key_Long-term toxicity to fish: NOEC (30d) ≥ 105 µg/L nominal (95.8 µg/L based on time weighted average concentrations) for Danio rerio (flow-through, freshwater, OECD 210, GLP)

3) Key_Long-term toxicity to aquatic invertebrates: NOEC (21d) ≥ 74.25 µg/L (geometric mean measured); EC10 (21d) > 74.2 µg/L (geometric mean measured) for Daphnia magna based on mortality, reproduction per introduced adult and reproduction per surviving adult (semi-static, freshwater, OECD 211, GLP)

4) Key_Toxicity to aquatic algae and cyanobacteria: ErC50(72h) 2.467 mg/L (geometric mean measured), ErC10(72h) 2.467 mg/L (geometric mean measured) for Desmodesmus subspicatus (static, freshwater, OECD 201, GLP)

Additional information

Due to the poor solubility (0.005141 mg/L at 25°C calculated by KOWWIN) and the very fast hydrolysis (DT50 = 37s; Neuland, 2020) of the test substance, no standard application could be used for the preparation of test solution for aquatic toxicity testing. As recommended in the OECD Guidance Document No. 23 on aqueous phase aquatic toxicity testing of difficult test chemicals (second edition, February 2019) solubility pre-experiments including analytical dose verification were performed before initiation of any aquatic toxicity testing to determinethe maximum dissolved concentration that can be achieved in the specific test solution under test conditions. Especially for the long-term studies the maintenance and reproducibility of test medium concentrations was determined by concurrent analytical measurements as well, to enable the performance of a valid main experiment. The results of these solubility pre-experiments were used to form a basis of, and justification for, the test solution preparation procedures adopted for the toxicity tests.

Short-term toxicity to fish

The acute toxicity of the test substance to fish was investigated according to EU Method C.1 (which is in most parts equivalent to OECD guideline 203). No GLP compliance was cited but the test facility is known to work under standard good laboratory practice. Danio rerio (Zebra fish) was used as test organism and exposed to nominal test concentrations of 1000, 3160 and 10000 mg/L of the test substance for 96 hours under static conditions. A control was running in parallel containing dilution water only. The test was carried out using a static design with a temperature range of 21.2 °C - 22.0 °C (control: 21.6 °C - 21.9 °C) and a pH range of 7.2 - 7.8 (control: 7.4 - 7.9) depending on the substance concentrations (1000, 3160 and 10000 mg/L). The light-dark cycle was 16 hours light / 8 h dark. Direct weighing was the method of administration followed by stirring and filtration. Any mortality and / or visible sublethal effects were observed and recorded throughout the test.

The 96h LC0 and the 96h LC100 were determined directly from the raw data and reported to be 3160 and 10000 mg/L, respectively. The 96h LC50 was calculated as geometric mean of the 96h LC0 and the 96h LC100 and was reported to be 5621 mg/L.

Long-term toxicity to fish

The study was performed under GLP according to OECD TG 210. Due to the fast hydrolysis of the test material (Neuland, 2020) the OECD Series on Testing and Assessment, No. 23 "Guidance Document on Aqueous-phase Aquatic Toxicity Testing of Difficult Test Chemicals" has also been taken into account.

The purpose of this study was to evaluate the toxicity of the registered substance to the early-life stages of fish. For this purpose, fertilised eggs of zebrafish (Danio rerio) were exposed in a flow-through test to aqueous test media containing the test item at nominal concentrations of 33 and 105µg/L under defined conditions. In parallel a solvent control (100 µL DMF/L) and a water control were tested. Due to the test item properties it was decided not to prepare the test media constantly by using a constant flow rate by peristaltic pumps or syringe pumps but to prepare the test media manually twice a day. In order to keep the test design in a manageable dimension the experiment will be running with two test concentrations only. According to OECD 210 this extended limit design is acceptable for the determination of a NOEC.

Following several independent pre-experiments to determine the solubility and stability of the test material in the test medium and the need to develop a reproducible analytical method, dimethylformamide (DMF) was used as solvent additive to achieve stable and reproducible concentrations in the flow-through system.

The test duration was 30 days after hatching. The eggs and larvae were observed daily for survival, hatching, abnormal appearance and behaviour. Additionally, at the end of the test, the individual length of all surviving fish was determined using a digital caliper. Also, at the end of the test all surviving fish were weighed (wet weight after blotting dry and dry weight) in groups by test vessel (replicate). Dead larvae were removed at least once daily and discarded. The test item concentrations in the test water taken at test start and after DAI 7, 14, 21, 28 and 34 were chemically analysed by LC-MS/MS.

Since TRIDI is hydrolytically unstable with a t(1/2) of 37 seconds at a temperature of 20 °C, it will be degraded during toxicity studies in aqueous media. Based on the result of a hydrolysis study according to OECD 111, 1,3,5-triisopropyl-2,4-diaminobenzene (TRIDA) will be formed as major hydrolysis product. Therefore, the quantification of the hydrolysis product 1,3,5-triisopropyl-2,4-diaminobenzene (TRIDA) was performed using liquid chromatography with MS/MS detection and the obtained results refer to the theoretical amount of TRIDA which can be built from TRIDI considering equimolar conversion.

Accordingly time weighted arithmetic mean measured concentrations of 27.5 and 95.8 µg test item/L were determined. However, as the mean test recoveries of the nominal test concentration varied between 83 and 91% (all test concentrations considered) the test item concentrations were determined to be stable during the run of the test and results were based on nominal test concentrations:

Hatching success: NOEC ≥ 105 µg test item/L

Mortality/Survival: NOEC ≥ 105 µg test item/L

Body Length: NOEC ≥ 105 µg test item/L

Body Weight (wet): NOEC ≥ 105 µg test item/L

Body Weight (Dry): NOEC ≥ 105 µg test item/L

Long-term toxicity to aquatic invertebrates

The purpose of this study was to evaluate the influence of the test material on mortality and reproduction of Daphnia magna during an exposure period of 21 days. Therefore, female Daphnia (< 24 hours old) taken from an in-house laboratory culture of the test facility, were exposed in a semi-static test to aqueous test media containing the test item at concentrations of nominal 105, 34, 11, 3.4, 1.1 and 0.34 µg test item/L (each in 100 µL DMF/L) ), a solvent control (100 µL DMF/L) and a control. Using HPLC MS/MS detection time weighted average concentrations of 74.2, 15.0, 8.53 and 0.704 µg test item/L were determined for the highest four test concentrations. No time weighted mean measured concentration was determined for the lowest test concentrations of 0.34 and 1.1 µg/L, as measured concentrations were below the limit of quantification of the HPLC-MS method accompanying the test. Furthermore the concentrations were below the determined 21d NOEC and do not have an influence on the outcome of the study.

The test animals were exposed to the test media for a period of 21 days under defined conditions. Following several independent pre-experiments to determine the solubility and stability of the test material in the test medium and the need to develop a reproducible analytical method, dimethylformamide (DMF) was used as solvent additive to achieve stable and reproducible concentrations in the test medium. The mortality of adults, the number of offspring per introduced adult and the number of offspring per surviving adult were compared with corresponding parameters in the controls.

Based on the obtained results no toxic effects against daphnia were observed up to the highest concentration of nominal 105 µg/L, corresponding to the time weighted average concentration of 74.2 µg/L, under exposure conditions. As analytical recoveries in the test media samples were not within 80 -120 % of nominal, the following endpoints were determined referring to the time weighted average concentrations of the test material:

EC50(21d) mortality > 74.2 µg/L

EC10(21d) mortality > 74.2 µg/L

NOEC (21d) mortality 74.2 µg/L

 

EC50(21d) reproduction per introduced adult > 74.2 µg/L

EC10(21d) reproduction per introduced adult > 74.2 µg/L

NOEC (21d) reproduction per introduced adult 74.2 µg/L

 

EC50(21d) reproduction per surviving adult > 74.2 µg/L

EC10(21d) reproduction per surviving adult > 74.2 µg/L

NOEC (21d) reproduction per surviving adult 74.2 µg/L

Toxicity to aquatic algae and cyanobacteria

The toxicity of the test substance to aquatic algae was tested according to EU Method C.3, which is equivalent to OECD TG 201, in a static freshwater test with Desmodesmus subspicatus (former name: Scenedesmus subspicatus) as test organism. The study was conducted under certificated GLP compliance.

Due to the test substance properties, a limit test was performed at the limit of water solubility under test conditions in order to demonstrate that the EC50values (based on yield as well as on growth rate) are greater than this concentration. Pre-experiments were conducted, which provided the concentration, as well as the biological and analytical design to be used in the main test. The final test concentration was chosen as nominal 100 mg/L, whereby the test medium was prepared by direct weighing, prolonged stirring and a subsequent settling period before withdrawal of the solved fraction in the middle.

For the test item concentration as well as for the control 6 replicates were prepared. The algal inocula for the experiment were taken from an exponentially growing pre-culture and were mixed with the nutrient medium to make up to a final cell density of about 5000 cells per milliliter in the test medium. The algae were exposed for a period of 72 hours and the cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction in growth rate and yield, relative to control cultures grown under identical conditions. All calculations were carried out using a statistical software programme. The maintenance of test item concentrations was proven by analytical measurements (HPLC MS/MS). Based on the analytical measurements in all test medium samples a geometric mean measured concentration of 2.647 mg/L was determined for the limit concentration of nominal 100 mg/L.

As analytical recoveries in the test media samples were not within 80 -120 % of nominal, all endpoints were determined referring to the geometric mean measured concentration of the test material. Accordingly, the following results were determined for yield (y) and growth rate (r) of the algal population within 72 h exposure period:

ErC50(72h) > 2.467mg/L

ErC10(72h) > 2.467 mg/L

NOErC (72h) 2.467 mg/L

EyC50(72h) > 2.467mg/L

EyC10(72h) > 2.467 mg/L

NOEyC (72h) 2.467 mg/L

Acute toxicity tests towards freshwater as well as marine algae were investigated for the read-across substance m-tolylidene diisocyanate (TDI) according to OECD Guideline 201 also, which are presented as supporting information. The rapid hydrolysis rate of the test substance was taken into consideration when presenting the test results.

The freshwater algal species Chlorella vulgaris was tested for a period of 96 hours under defined conditions, resulting in a 96h EC50of 4300 mg/L and a NOEC of 1000 mg/L (Tadokoro et al., 1997).

The marine algal species Skeletonema costatum was tested for a period of 96 hours under defined conditions, resulting in a 96h EC50 of 3230 mg/L (Tadokoro et al., 1997).

Toxicity to aquatic microorganisms

The acute toxicity of the test substance to microorganisms was investigated in accordance with OECD Guideline 209 (Kanne, 1989). Activated sludge was used in the static freshwater experiment with an exposure time to the test substance of 3 hours. The EC50 value of greater or equal to 10000 mg/L is given as result, with the remark of water insolubility for the substance.

Toxicity to aquatic plants (other than algae) and other aquatic organisms

In accordance to REACH Regulation (EC) 1907/2006 this information is not mandatory for a registration of a chemical at a tonnage band of 100 - 1000 tons/year.

Considering all available data on short- and long-term toxicity to aquatic organisms and taking into account the poor water solubility of the registered substance (0.005141 mg/L at 25°C calculated by KOWWIN), no acute or chronic hazard was determined for the aquatic environment up to and clearly above the limit of solubility or relevant limit concentrations, whichever is the lowest. Furthermore rapid degradation from the environment is proven by the fast hydrolysis (DT50= 37s, Neuland 2020). Hence, no acute or chronic hazard was determined for the aquatic environment and the substance does not need to be classified according to Regulation (EC) No 1272/2008.

Due to the rapid hydrolysis of the registered substance and due to the design and duration of the aquatic studies conducted, the determination of the toxicity of the degradation products was automatically included. Confirmation of this is provided by the analytical measurements for dose verification accompanying the long-term studies, for which the sum of TRIDI and the main hydrolysis product TRIDA was determined. Since neither an acute nor a chronic effect was determined in the available aquatic studies for all trophic levels up to the solubility limit or relevant limit concentrations, an acute or chronic toxicity of the degradation products in the relevant concentrations can also be excluded. Furthermore, the results of the available bioaccumulation study with the main hydrolysis product TRIDA (Gourlay, 2021) confirm, that there is no potential for bioaccumulation.