1,3,5-tris(3-mercaptopropyl)-1,3,5-triazinane-2,4,6-trione

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-05-28 to 2018-07-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 0.35, 0.50, 0.70, 1.0 and 1.4 mg/L (nominal)
- Sampling method: Samples of test item treatment, blank control and solvent control were taken for analysis at the beginning of exposure (0 h), at the end of exposure (96 h) and at 24, 48 and 72 h before and after test solution renewal. On each occasion, three samples were taken from each test item treatment group and one from blank control and solvent control.

Vehicle:

yes

Remarks:

1mL N,N-dimethy| formamide (DMF)

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: See Section "Any other information on materials and methods incl. tables" below
- Controls: Yes
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No, solvent DMF applied

Test organisms (species):

other: Rare minnow (Gobiocypris rarus)

Details on test organisms:

TEST ORGANISM
- Rare minnow (Gobiocypris rarus)
- Strain: n.a.
- Source: Rare minnows (Code No.: Rare minnow C20170802) were reproduced and maintained in the water renewal system of CTI-SET
- Length at study initiation (length): 2.0 - 4.0 cm

ACCLIMATION:
- Acclimation period: 7 d
- Acclimation conditions: The fish were acclimated in the water having the same quality as the test water. During the seven days of acclimation before the test, the water temperature was maintained in the range of 21 - 25 °C and the change was not more than 2 °C. 12 hours light was given daily. Dissolved oxygen concentration was above 80% of air saturation value.
- Feeding frequency: The fish were fed daily until 24 hours before the test. The fish were not fed during the study.
- Health during acclimation (any mortality observed): During the 7 days acclimation period prior to the test, the total mortality was 0%.

Test type:

semi-static

Water media type:

other: Tap water dechlorianted by aeration

Limit test:

no

Total exposure duration:

96 h

Hardness:

10 - 250 mg/L (calculated as CaCO3)

Test temperature:

21 - 25 °C (within the range of 2 °C)

pH:

6.0 - 8.5

Dissolved oxygen:

Not less than 60% of the air saturation value

Nominal and measured concentrations:

0 (control), 0.35, 0.50, 0.70, 1.0 and 1.4 mg/L (nominal)
0 (control), 0.026, 0.074, 0.18, 0.51 and 0.81 mg/L (geom. mean of measured)

Details on test conditions:

TEST SYSTEM
- No. of organisms per group: 10
- Renewal rate of test solution (frequency/flow rate): Every 24 h

OTHER TEST CONDITIONS
- Photoperiod: 12 hours photoperiod daily
- Loading rate: <1 g fish/litre

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.43 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.05 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

The EPA software TRIMMED SPEARMAN-KARBER METHOD (TSK) VERSION 1.5 was used to calculated the L050 and its 95% confidence limits.

Sublethal observations / clinical signs:

Observations

At the end of exposure, there was no mortality or abnormal symptom in the blank control and solvent control. The mortality at the nominal concentrations of 0.35, 0.50, 0.70, 1.0 and 1.4 mg/L was 0 %, 90 %, 100 % and 100 %, respectively, and there was no abnormal behavior.

Concentration analysis

Samples of the treatment, blank control and solvent control groups were taken for analysis at the beginning of exposure (0 h), at the end of exposure (96 h), and before and after each renewal of test solution. The result of concentration analysis showed that the test item was not detected in the solution of blank control and solvent control. The measured concentrations of test item in solutions were not maintained in the range of 80 % - 120 % of measured initial concentrations after 24, 48, 72 and 96 hours exposure. Therefore, the calculation of effect concentrations was based on the geometric mean of measured concentrations. The geometric means of measured concentrations of test item were 0.026, 0.074, 0.18, 0.51 and 0.81 mg/L for the nominal concentrations of 0.35, 0.50, 0.70, 1.0 and 1.4 mg/L, respectively.

LC50

The EPA software TRIMMED SPEARMAN-KARBER METHOD (TSK) VERSION 1.5 was used to calculate the LC50 and its 95% confidence limits.

The LC50 values of the test item to rare minnow are summarized in Table 1.

Exposure time (h)	Based on nominal concentration (mg/L)		Based on arithmetic mean measured concentration (mg/L)
	LC50	95% confidence limit	LC50	95% confidence limit
24	0.68	0.61 – 0.76	0.17	0.13 – 0.23
48	0.59	n.a.	0.12	n.a.
72	0.52	0.46 – 0.57	0.08	0.06 – 0.11
96	0.43	0.41 – 0.46	0.05	0.04 – 0.06

Based on nominal concentration, the 96 h maximum concentration causing no mortality (LC0) was 0.35 mg/L (geometric mean measured concentration of test item was 0.026 mg/L). and the 96 h minimum concentration causing 100% mortality (LC100) was 0.70 mg/L (geometric mean measured concentration of test item was 0.18 mg/L).

Validity criteria fulfilled:

yes

Remarks:

Validity criteria for mortality in control group and concentration of dissolved oxygen during study fulfilled. The concentration of test item could not be maintained in the range 80 to 120 %., though a semi-stic design was chosen.

Conclusions:

The 96 h LC50 of the test item in rare minnow (Gobiocypris rarus) was 0.43 mg/L (based on nominal concentration; the geometric mean measured concentration was 0.05 mg/L) and its 95% confidence interval (C.I.) was 0.41 - 0.46 mg/L (based on nominal concentration; the 95% C.I. was 0.04 - 0.06 mg/L based on geometric mean measured concentration).

Executive summary:

In the course of a 96-h test with rare minnow (Gobiocypris rarus) according to OECD Guideline 203 (July 1992) applying nominal test concentrations of 0.35, 0.50, 0.70. 1.0 and 1.4 mg/L corresponding to geometric means of measured concentrations of 0.026, 0.074, 0.18, 0.51 and 0.81 mg/L, under semi-static conditions. Based on the structure of the test item, it was assumed that the test item was hydrolyzed and/or oxidized. Therefore, the calculation of effect concentrations was based on the geometric mean of measured concentrations. The 96-h LC₅₀was 0.05 mg/L. The NOEC value based on mortality was 0.026 mg/L. No abnormal behavior was reported for any group. Based on the results of this study, 1,3,5-Tris-(3-mercaptopropyl)isocyanurate would be classified as acute and chronic category 1 to rare minnow in accordance with the CLP regulation ((EU) Nr. 1272/2008).

This toxicity study is classified as acceptable and satisfies the guideline requirement for a Fish, Acute Toxicity Test according to OECD guideline 203.

Results Synopsis

 

Test organism size (length): 2.0 - 4.0 cm

Test type: Semi-static

 

Measured effect levels (geom. mean):

96-h LC₀ =      0.026 mg/L

96-h LC₅₀ =    0.05 mg/L [95 % C.I.: 0.04 to 0.06 mg/L]

96-h LC₁₀₀ =  0.18 mg/L

 

Endpoint Effected: Mortality

Description of key information

In an acute toxicity test according to OECD guideline 203 the fish species rare minnow (Gobiocypris rarus) was exposed to the test item and a 96-h LC50 of 0.05 mg/L was determined (based on the geometric mean of measured concentrations) and its 95 % confidence interval was 0.04 - 0.06 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.05 mg/L