N-(1-oxotetradecyl)sarcosine

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish embryo acute toxicity (FET)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Refer to the analogue approach justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

4.256 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% confidence interval: 2.95 - 6.14 mg/L

Remarks:

Source: RA-A, CAS 30364-51-3, Ibacon, 133991238, 2018, D. rerio, 96 h

Description of key information

LC50 (96 h) = 4.256 mg a.i./L (geom. mean meas., OECD 236, D. rerio); read-across

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

4.256 mg/L

Additional information

There is no study available, in which the short-term toxicity of N-(1-oxotetradecyl)sarcosine (CAS 52558-73-3) to fish was assessed. Therefore, read-across to the structurally related source substance Sodium N-methyl-N-(1-oxotetradecyl)aminoacetate (CAS 30364-51-3) was conducted according to Regulation (EC) No 1907/2006 (Annex XI, 1.5) in order to fulfill the standard information requirements laid down by the regulation. The chemical properties of the target and source substance are similar due to their structural similarities, i.e. the sarcosine head group and the hydrocarbon tail. In addition, at physiological pH values (above 6) the target substance is expected to be present in its anionic form just like the source substance. As a result, the chemistry of the target and source substances in solutions above pH 6 is expected to be similar. Thus, the source substance is considered a suitable representative for the assessment of the aquatic toxicity of the target substance. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

In the available GLP study with the source substance Sodium N-methyl-N-(1-oxotetradecyl)aminoacetate (CAS 30364-51-3), the short-term toxicity to fish was assessed according to OECD guideline 236.

A semi-static test with daily test medium renewal was performed, in which Zebrafish embryos (≤ 16 cell stage) were exposed to the five nominal test item concentrations of 0.94, 1.88, 3.75, 7.50, and 15.0 mg a.i./L (corresponding to 3.04, 6.08, 12.14, 24.27, and 48.54 mg test item/L) for 96 h. A negative control, positive control and internal (procedural) control were run in parallel. Hatching rates were determined and acute lethality was assessed by daily assessment of the coagulation of embryos, lack of somite formation, the non-detachment of the tail-bud from the yolk sac, and the lack of heart beat. The actual test item concentrations were analytically verified by LC-MS every 24 h in fresh and aged media.

The average measured test item concentration at the start of the test and at the renewal of the test media was 88% of nominal in fresh media and 67% of nominal in aged media after 24, 48, 72 and 96 h. Since the concentrations of the test item were not within ± 20% of the initial concentrations during the test, results were based on the geometric mean measured concentrations of 0.67, 1.44, 2.95, 6.14, and 10.70 mg a.i./L (corresponding to 2.17, 4.66, 9.55, 19.87, and 34.63 mg test item/L).

After 96 h, all embryos survived up to the test item concentration of 2.95 mg a.i./L. All embryos died during exposure to the test concentrations of 6.14 and 10.7 mg a.i./L. Hatching success in the control and in all test item concentration up to 1.44 mg a.i./L was 100%. Hatching success in the test item concentratin of 2.95 mg a.i./L was 95%. The internal plate controls showed 100% hatching success and thus confirmed the validity of the testing procedure. The obtained LC50 (96 h) is 4.256 mg a.i./L based on the geometric mean measured concentrations.