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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Remarks:

Degradation product

Adequacy of study:

key study

Study period:

1989-05-17 to 1989-05-19

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
As the substance hydrolyses immediately in contact with water, data from the major constituent of the hydrolysate (bis(2 -ethylhexyl)amine is used to assess this endpoint. This constituent is also the most hazardous constituent to the aquatic environment. For further read across justification see IUCLID chapter 6.1 and CSR chapter 7.1.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Parent substance EC 401 -280 -0
The acute toxicity of the substance EC 401-280-0 to Daphnia was assessed according to OECD guideline no. 202 (1984). The respective EC50 24 h is 9.3 mg/L, based on nominal concentrations. As the exposure was only 24 hours, this data is only used as supportive information.

Furthermore, as the substance hydrolyses immediately in contact with water, data from the major constituent of the hydrolysate (bis(2 -ethylhexyl)amine is used to assess this endpoint. This constituent is also the most hazardous constituent to the aquatic environment. For further read across justification see IUCLID chapter 6.1 and CSR chapter 7.1.

Hydrolysis products
bis(2 -ethylhexyl)amine
The reported 48-h EC50 of bis(2-ethylhexyl)amine on Daphnia magna was 2.2 mg/L (nominal value) in a test using Tween 80 as a solvent. The EC50 was determined using non-neutralised samples (BASF AG 1/0500/2/89-0500/89, 1989).
Based on the results from a long-term reproduction study with Daphnia magna, the substance is classified as Chronic Category 1. Comparing the available aquatic toxicity data on the substance EC 401 -280 -0 with the data of bis(2 -ethylhexyl)amine shows that aquatic toxicity is in the same range. In most cases the derived effect concentrations of bis(ethyhexyl)amine are lower.Therefore, aquatic toxicity data of the major and the most hazardous component of the hydrolysate (bis(2-ethylhexyl)amine) is used as worst case to assess the acute toxicity to aquatic invertebrates of the substance EC 401-280-0 and its hydrolysate.

3. ANALOGUE APPROACH JUSTIFICATION
The aquatic toxicity data of the major and the most hazardous component of the hydrolysate (bis(2-ethylhexyl)amine) is used as worst case to assess the acute toxicity to aquatic invertebrates of the substance EC 401-280-0 and its hydrolysate.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

no

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Tween 80
- Concentration of vehicle in test medium (stock solution): 100 mg/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Inhouse, originally obtained from Institut National de Recherche Chimique Appliquee, France in 1978
- Age at study initiation (range): 2 - 24 h

ACCLIMATION
- Type of food: green algae
- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

total: 2.7 ± 0.5 mM

Test temperature:

292 - 294 K

pH:

8.0 ± 0.5

Nominal and measured concentrations:

0.039, 0.078, 0.156, 0.312, 0.624, 1.25, 2.5, 4.99, 10, 20 mg/L as well as a control and a solvent control

Details on test conditions:

TEST SYSTEM
- Test vessel: centrifuge tubes
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: artificial freshwater
- Ca/mg ratio: 4:1
- Conductivity: 600 - 700 µSiemens/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0 and 48 h

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: diffuse light


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
immobility after 0, 3, 6, 24 and 48 hours

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

2.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

7.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.624 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Immobile daphnids

Nominal conc.(mg/l)	Immobile daphnids after
	0 h	3 h	6 h	24 h	48 h
0	0	0	0	0	0
Vehicle	0	0	0	0	0
0.039	0	0	0	0	0
0.078	0	0	0	0	0
0.156	0	0	0	0	1
0.312	0	0	0	0	2
0.624	0	0	0	0	2
1.25	0	0	0	0	4
2.5	0	0	0	2	11
4.99	0	0	0	4	17
10	0	1	1	13	20
20	0	9	11	20	20

pH values

Nominal conc.(mg/l)	pH values after
	0 h	48 h
0	8.05	8.08
Vehicle	8.06	8.04
0.039	8.05	8.1
0.078	8.04	8.11
0.156	8.04	8.11
0.312	8.03	8.1
0.624	8.03	8.09
1.25	8.03	8.08
2.5	8.03	8.08
4.99	8.05	8.07
10	8.07	8.05
20	8.09	8.02

Validity criteria fulfilled:

yes

Conclusions:

The 48-h EC50 of Daphnia magna exposed to bis(2-ethylhexyl)amine was determined to be 2.2 mg/L.

Description of key information

The 48-h EC50 of Daphnia magna exposed to bis(2-ethylhexyl)amine was determined to be 2.2 mg/L. This result is used to assess the acute toxicity of substance EC 401-280-0 and its hydrolysate to aquatic invertebrates.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

2.2 mg/L

Additional information

Parent substance EC 401 -280 -0

The acute toxicity of the substance EC 401-280-0 to Daphnia was assessed according to OECD guideline no. 202 (1984). The respective EC50 24 h is 9.3 mg/L, based on nominal concentrations. As the exposure was only 24 hours, this data is only used as supportive information.

Furthermore, as the substance hydrolyses immediately in contact with water, data from the major constituent of the hydrolysate (bis(2 -ethylhexyl)amine is used to assess this endpoint. This constituent is also the most hazardous constituent to the aquatic environment. For further read across justification see IUCLID chapter 6.1 and CSR chapter 7.1.

Hydrolysis products

bis(2 -ethylhexyl)amine

The reported 48-h EC50 of bis(2-ethylhexyl)amine on Daphnia magna was 2.2 mg/L (nominal value) in a test using Tween 80 as a solvent. The EC50 was determined using non-neutralised samples (BASF AG 1/0500/2/89-0500/89, 1989).

Based on the results from a long-term reproduction study with Daphnia magna, the substance is classified as Chronic Category 1. Comparing the available aquatic toxicity data on the substance EC 401 -280 -0 with the data of bis(2 -ethylhexyl)amine shows that aquatic toxicity is in the same range. In most cases the derived effect concentrations of bis(ethyhexyl)amine are lower.Therefore, aquatic toxicity data of the major and the most hazardous component of the hydrolysate (bis(2-ethylhexyl)amine) is used as worst case to assess the acute toxicity to aquatic invertebrates of the substance EC 401-280-0 and its hydrolysate.

formaldehyde

Acute toxicity of formaldehyde to invertebrates was determined in a study with Daphnia pulex and a LC50 of 5.8 mg/L was derived (Tisler, 1997).

Therefore, the test substance is considered as acutely toxic to aquatic invertebrates.