1-(N,N-bis(2-ethylhexyl)aminomethyl)-1,2,4-triazole

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2004 - February 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 225 (Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method:Samples were taken at start of exposure phase (7 d after spiking the sediment and setting up the sediment-water systems and at the end of the test (35 d after spiking the sediment and setting up the sediment-water systems). Three different types of samples were taken:
Overiying water
Pore water and
Sediment (after centrifugation)

Vehicle:

yes

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Details of spiking: test item dissolved in acetone; test item coated on quartz sand, then mixed with wet sediment
- Equilibration time: 7 d prior to addition of organisms
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone

Test organisms (species):

other: Lumbriculus variegatus

Details on test organisms:

TEST ORGANISM
- Common name: Lumbriculus variegatus (Müller)
- Source: Fischfutter Etzbach (D-53894 Mechemich-Bergheim, Germany)
- Feeding during test: spiked artificial sediment according to OECD draft guideline No. 218 (OECD 2002); peat content 5% of sediment d.w.; addition of urtica-powder (0.25% on dry sediment) and cellulose-powder (0.25% on dry sediment) before application of test item; no additional feeding

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

artificial sediment

Limit test:

no

Duration:

28 d

Exposure phase:

total exposure duration

Hardness:

254 mg/L (as CaCO3)

Test temperature:

20.4°C

pH:

7.9

Dissolved oxygen:

98 %; 8.8 mg/L

Ammonia:

3.73 mg/L (mean in control)

Nominal and measured concentrations:

Nominal: 300.0, 130.4, 56.7, 24.7, and 10.7 mg/kg sediment dry weight
Measured:
Recovery in sediment: 116.9 % (nominal 56.7 mg/kg sediment dry weight), 121.8 % (nominal 300 mg/kg sediment dry weight)
Recovery in pore water: 0.1 % (nominal 56.7 mg/kg sediment dry weight), 0.2 % (nominal 300 mg/kg sediment dry weight)
Recovery in overlying water: 0.9 % (nominal 56.7 mg/kg sediment dry weight), 1.3 % (nominal 300 mg/kg sediment dry weight)

Details on test conditions:

TEST SYSTEM
- Test container (material, size):glass container consisting of a layer of quartz sand as used for the artificial sediment, and reconstituted water.
- Amount of soil or substrate: approximately 80 or 200 g w.w.
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per vehicle control: 6

OTHER TEST CONDITIONS
- Photoperiod:16 h light
- Light intensity: 569 Ix

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The total number of worms per replicate, and the total dry weight of the worms per replicate were assessed. In order to estimate mortalities, the numbers of worms that did not react to a gentle stimulus or showed signs of decomposition were considered dead. In cases where the number of worms found on day 28 of the exposure period was less than the number of worms introduced to the vessel, the number of missing worms was added to the number of worms observed dead. In these cases, survival is defined as the difference between the number of worms introduced and the sum of dead and missing worms.

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Range finding study: In a range-finding test (non-GLP) performed prior to the start of the definitive test, all test organisms died at 500 mg test item/kg sediment dry weight, while all test organisms survived and low reproduction was observed at 100 mg/kg sediment dry weight.
- Test concentrations:300.0, 130.4, 56.7, 24.7, and 10.7 mg/kg sediment dry weight

Reference substance (positive control):

no

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

56.7 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 300 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

134.3 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

With respect to biomass and reproduction the test showed a clear dose-response relationship.
For the endpoint survival there was no dose-response relationship (negligible mortality was observed up to the highest concentration level). Therefore no LCx-values could be calculated.

Conclusions:

The 28-d NOEC of Lumbriculus variegatus exposed to the substance EC 401-280-0 and its hydrolysis products was determined to be 56.7 mg/L

Description of key information

The 28-d NOEC of Lumbriculus variegatus exposed to the substance EC 401-280-0 and its hydrolysis products was determined to be 56.7 mg/L

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater sediment:

56.7 mg/kg sediment dw

Additional information

Parent substance EC 401 -280 -0

The toxicity of Lumbriculus variegatus to the substance EC 401 -280 -0 was investigated in a non-guideline study (ECT, 2005). The aquatic oligochaete was exposed to the test item in spiked sediment at the nominal concentrations of 10.7, 24.7, 56.7, 130.4 and 300 mg/kg sediment dry weight. The overall NOEC based on mortality, reproduction and biomass was determined to be 56.7 mg/kg sediment dw. It can be assumed that the test item was completely degraded by hydrolysis. Therefore, NOEC and EC50 refer to the nominal concentration. As substance EC 401 -280 hydrolyses immediately in contact with water it can be anticipated that organisms in sediment toxicity tests are exposed to the hydrolysate and that the derived toxicity refers to this hydrolysate. For this reason additional data on sediment toxicity with each hydrolysis product are not needed.

Hydrolysis products

No data on sediment toxicity are available for the different hydrolysis products.