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

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-01-07 to 2013-01-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

Qualifier:

equivalent or similar to guideline

Guideline:

other: ISO 10706

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all
- Sampling days: 0, 1, 2, 8, 9, 15, 16

Details on test solutions:

The stock solution (1 mg/L) was prepared by pipetting 2.8µL (2.27 mg based on the density, d=0.803 g/cm3) test substance into 2.27 L of test medium in a glass aspirator bottle (approx. 2 L) with a bottom side-outlet attached to a stopcock. The volume of test medium nearly filled the bottl leaving a small airspace so that the substance remained in contact with the test medium, but did not contact the bottle stopper. The bottle was immediately closed after adding the test substance and the solution gently stirred for approximately one day. The stirring was slow enough that no vortex formed on the surface at approx. 100 RPM. The bottle was inspected for the presence of undissolved substance on the solution surface. The stock solution was removed from the bottom of the bottle to separate it from any potentialundissolved portion remaining on the surface and visually inspected for the presence of any undissolved test substance. Once removed from the saturation bottle, the stock solution was handled in sealed vessels as far as possible to avoid atmospheric loss. The test solution for the control group was prepared in the same manner but without test substance.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Institut National de Recherche Chimique Appliquée (France, 1978), cultured continuously in BASF SE, Ecotoxicology Laboratory since 1978
- Age of parental stock (mean and range, SD): maximum 4 weeks
- Feeding during test: yes
- Food type: live green algae Desmodesmus subspicatus
- Amount: Day of test: 0-3 (0.10 mg TOC), 4-5 (0.12 mg TOC), 6-7 (0.14 mg TOC), 8-21 (0.20 mg TOC)
- Frequency: daily

ACCLIMATION
- Acclimation conditions (same as test or not): same as test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

21 - 22°C

pH:

7.5 - 8.6

Dissolved oxygen:

6.7 - 9.3 mg/L

Nominal and measured concentrations:

Nominal: 0 (control), 0.018, 0.032, 0.056, 0.10, 0.18 mg/L

Measured (TWA):

Details on test conditions:

TEST SYSTEM
- Test vessel: glass flask (50 mL nominal volume)
- Type (delete if not applicable): closed
- Aeration: none
- Material, size, headspace, fill volume: no headspace, fill volume approx. 50 mL
- Renewal rate of test solution (frequency/flow rate): 3 times per week
- No. of organisms per vessel: 1 parent
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Biomass loading rate: 0.02 animals/mL

OTHER TEST CONDITIONS
- Photoperiod: 16 light : 8 dark

Reference substance (positive control):

yes

Remarks:

sodium chloride

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.069 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: per surviving parent as well as per introduced parent

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.133 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: per surviving parent as well as per introduced parent

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.039 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.069 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.069 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: days to first brood

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.133 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: days to first brood

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.269 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

All test solutions were visibly colorless and clear throughout each renewal period. No undissolved test substance or other unusual manifestations were observed.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: 48h EC50: 4.80 g/L (2012-12-12)

Analytically measured concentration

Nominal concentration [mg/L]	Analytically measured concentration
	Mean Initial		Mean 24 h old		Time-weighted mean
	[mg/L]	[%]^a	[mg/L]	[%]^b	[mg/L]^c	[%]^a
0 (control)	n.d.	-	n.d.	-	n.d.	-
0.018	0.026	143	0.020	78	0.023	126
0.032	0.040	132	0.036	85	0.039	122
0.056	0.070	132	0.065	88	0.069	124
0.100	0.140	140	0.127	90	0.133	133
0.180	0.270	150	0.273	101	0.269	150

^a % of nominal concentration

^b % of mean initial

^c based on 3 renewal period days

n.d. not detected

Reproduction and mortality after 21 d

Time-weighted mean concentration [mg/L]	Mortality (parent animals)	Reproduction per surviving parent		Reproduction per introduced parent
		Mean living young	% effect^b	Mean living young	% effect^b
0 (control)	0	128 (10.5%^a)	-	128	-
0.023	0	126	-	126	-
0.039	1^c	113	-	113	-
0.069	2^c	105	-	105	-
0.133	1^c	82**	36**	82**	36**
0.269	3**	8**	94**	6**	95**

* p ≤ 0.05   ** p ≤ 0.01

^a coefficient of variation for control fecundity based on surviving parent

^b effect relative to control

^c accidental or inadvertent death, replicates excluded in data evaluation

Other biological results

Time-weighted mean concentration [mg/L]	Growth (mean length in mm)	Mean % immobile young	Mean days to first brood	Mean % aborted eggs
0 (control)	4.4	0.4	8.5	0.5
0.023	4.3	0.4	8.7	0.8
0.039	4.2	0.2	8.6	0.9
0.069	4.1**	0.9	8.9	0.3
0.133	4.0**	4.0	11.2**	1.2
0.269	3.3**	-^a	19.6**	-^a

* p ≤ 0.05   ** p ≤ 0.01

^a due to the low number of living young in test group 5, the number of aborted eggs and number of immobile young were set to missing and not included in the evaluation

Validity

In the control, mortality of parent animals up to the end of the test should be <= 20%.

In the control, the mean number of living young per parent animal that survived the test should be >= 60.

All validity criteria were met in this test.

Validity criteria fulfilled:

yes

Conclusions:

The 21-d NOEC of Daphnia magna exposed to bis(2-ethylhexyl)amine was determined to be 0.069 mg/L.

Description of key information

The 21-d NOEC of Daphnia magna exposed to bis(2-ethylhexyl)amine was determined to be 0.069 mg/L. This result is used to assess the chronic toxicity of the 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:

NOEC

Effect concentration:

0.069 mg/L

Additional information

Parent substance EC401 -280 -0

No data on chronic toxicity to invertebrates are available. 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

In a long-term study with Daphnia magna according to OECD 211 with the major hydrolysis product bis(2-ethylhexyl)amine performed under GLP, the 21 -d NOEC (reproduction, growth) was determined to be 0.069 mg/L (TWA concentration).

1H-1,2,4 -triazole

No data on chronic toxicity to invertebrates are available. The substance is not acutely toxic to invertebrates.

The EC50 for fish is 97 mg/L. No toxicity to microorgamisms was observed. Based on the ErC50 72h algae is the most sensitive organism (ErC50 10-100mg/L), however the ErC10 72h algae is > 1mg/L. Chronic aquatic toxicity data are only available on fish (OECD 215) showing no effect on growth rate and mortility (NOEC 28d > 100mg/L) (ECHA disseminated REACH Dossier, 16 July 2014). Based on these data no chronic toxicity in Daphnia is expected. 1H-1,2,4-triazole is only a minor degradation product of EC 401-280-0.Thus, aquatic toxicity data on 1H-1,2,4-triazole are not regarded as relevant to evaluate the acute and chronic aquatic toxicity of the substance EC 401-280-0 and its hydrolysate.

Formaldehyde

No reliable data on long-term toxicity of formaldehyde on aquatic invertebrates are available.

As formaldehyde is readily biodegradable, data on chronic toxicity are not considered to be relevant to assess chronic toxicity of the substance EC 401-280- 0 and its hydrolysate.

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