1,3,5-triazine-2,4,6(1H,3H,5H)-trithione

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-06-23 to 2006-07-14

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

adopted 1998

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,3,5-triazine-2,4,6(1H,3H,5H)-trithione

EC Number:

211-322-8

EC Name:

1,3,5-triazine-2,4,6(1H,3H,5H)-trithione

Cas Number:

638-16-4

Molecular formula:

C3H3N3S3

IUPAC Name:

1,3,5-triazine-2,4,6(1H,3H,5H)-trithione

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Freshly prepared media were sampled at test start and on days 10 and 19; old media were sampled on days 3, 12 and 21 after transfer of animals to new medium.
Sampling method: The analytical samples were collected 10 mL each with graduation of the test tube in the glass-stoppered 10mL capacity test tubes.
- Sample storage conditions before analysis: Samples were stored at room temperature for analysis on the same day or stored at 4 °C for analysis within 4 days.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 100 mg/l test substance was produced. To obtain the desired test concentration levels, the stock solution was diluted with dilution water or directly used for the highest test concentration.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Source: Received on 04 August 1997 from the Ministry of the Environment, Institute for Environmental Studies, Japan
- Age of parental stock (mean and range, SD): Parental rearing period was from 06 Jun to 22 Jun 2006
- Age of test animals: < 24 h
- Feeding during test
- Food type: P. subcapitata
- Amount: 0.1 mg C per day and daphnia for up to 4 day olds; 0.15 mg C per day and daphnia for 5 - 10 day olds; 0.2 mg C per day and daphnia for 11 day olds and older animals.
- Frequency: once per day

CULTURE CONDITIONS
- Subculture breeding: max. 4 weeks of breeding period, water exchange 2 times per week
- Type and amount of food: P. subcapitata, 0.1 - 0.2 mg C per animal and day
- Feeding frequency: 3 . 5 days per week
- Health during culture (any mortality observed): Death rate of parents 2 weeks before test start was 3.3% and emergence of diapause eggs and males was not identified.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test conditions

Hardness:

200 - 250 mg/L CaCO3

Test temperature:

20 ± 1 °C, measured 19.0 to 20.7

pH:

6.0 - 9.0 (fluctuation within 1.5), measured 7.3 to 8.4

Dissolved oxygen:

> 5 mg/L, measured 8.5 mg/L to 10.7 mg/L

Nominal and measured concentrations:

Nominal concentrations: control, 2.7 mg/L, 4.6 mg/L, 7.8 mg/L, 13.2 mg/L, 22.4 mg/L, 38.1 mg/L
Mean measured concentrations (time weighted average): control, 2.4 mg/L, 4.3 mg/L, 7.3 mg/L, 12.6 mg/L, 21.6 mg/L, 38.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Beakers
- Type (delete if not applicable): covered by a glass cover
- Material, size: Glass, 100 ml
- Aeration: No aeration of test vessels; dilution water was aerated > 1 h before use in the test.
- Renewal rate of test solution (frequency/flow rate): Test solutions were renewed on days 3, 5, 7, 10, 12, 14, 17 and 19.
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M7 medium was used
- Intervals of water quality measurement: Temperature, oxygen, hardness and pH were measured at test start and at water renewal time points.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light/8 h dark
- Light intensity: 800 - 1200 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Immobilisation and abnormalities were recorded daily.
- The number of surviving fry was counted daily and the occurrence of dead fry, aborted eggs and diapause eggs was recorded.
- Occurrence of eggs in the brood chambers and the day of hatching was recorded.
- The body length of the parental daphnia was measured at test end.

RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study: The short-term toxicity study with Daphnia magna revealed an EC(48h) of 38.1 mg/L. This concentration was chosen as the highest test concentration for the long-term study.

Reference substance (positive control):

not specified

Remarks:

substance not stated in the report

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

8.39 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% CL: 6.4-10.99 mg/L

Effect concentrations 2

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

8.62 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 95% CL = 8.17 - 9.11 mg/L

Remarks:

cumulative number of fry

Effect concentrations 3

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

4.3 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: reproduction and growth

Remarks on result:

other: based on mean cumulative counts of litter size and body length of parent Daphnia

Effect concentrations 4

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

4.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction and growth

Effect concentrations 5

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

6.31 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

1,3,5-triazine-2,4,6(1H,3H,5H)-trithione, trisodium salt (TMT)

Basis for effect:

other: reproduction and growth

Remarks on result:

other: recalculated value

Details on results:

A mean value (time-weighted average) of the measured concentration has been used to calculate the effect values, since the measured concentrations exceeded ± 20 % of the established concentration range.
The average body length was 4.1±0.14 mm in the 2.4 mg/L section, 4.1 ± 0.25 mm in the 4.3 mg/L section, and 3.8 ± 0.20 mm in 7.3 mg/L section.
Day of first brood: control mean 9.8 days, test concentration 9.5 to 11.3 days

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50 (48h): 0.9 mg/L (95% CL: 0.74 - 1.1 mg/L)
- Date of sensitivity test: 12 Mar to 14 Mar 2006

Reported statistics and error estimates:

The EC50 value was calculated using the Probit method. The NOEC value was calculated using EcoTox-Statics; as a methodology, test was conducted for equality of variance by Bartlett method for the control plot and all the concentration sections: in case of equality of variance, ANOVA was conducted; and in case there was significant difference between the concentration sections, a multiple comparison test by Dunnett method was conducted. When there was no equality of variance, rank sum test by Kruskal-Wallis was conducted; and when there was significant difference between the concentration sections, multiple comparisons by Dunnett method of nonparametric was performed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 21-day-chronic toxicity of the test substance to Daphnia magna was studied under semi-static conditions. Daphnids were exposed to dilution water (control) and test chemical at measured (time-weighted average) concentrations of 2.4, 4.3, 7.3, 12.6, 21.6, and 38 mg test material/L. The 21 day LC50 based on mortality was 8.39 mg test material/L (95% CL: 6.4-10.99 mg/L). The 21-day NOEC based on reproduction/growth was 4.3 mg test material/L.