Reaction mass of diethyl adipate and diethyl glutarate and diethyl succinate

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

Adequacy of study:

key study

Study period:

From September 2017 to April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
Sampling schedule for chemical analysis during the test period:
o at the start of exposure: S(R) Control(XR) C1(XR) C2(RR) C3(XR) C4(RR) C5(XR)
o at the end of exposure: Control(XR) C1(XR) C2(RR) C3(XR) C4(RR) C5(XR)
S Stock solution
C1–5 Test solutions
X Sample to be analysed
R Reserve sample
Samples of untreated test medium were provided to the analytical laboratory in order to
determine the recovery of the analytical method with the specific test medium

- Sampling method:
The nominal volume per sample was 10 mL mixed with 2 mL of acetonitrile. The volume of each sample was recorded. After sampling and before storage and shipment, the samples were stabilised by adding acetonitrile directly after sampling (acetonitrile volume: 20% of the water sample volume; i.e. 10 mL of sample were mixed with 2 mL of acetonitrile). Additional duplicate samples of the test solutions were stored
as additional reserve.

- Sample storage conditions before analysis:
After sampling and before shipment, all samples were stored in amber glass bottles in the dark at a temperature of ≤ -18°C. A record was kept for each sample.

Vehicle:

no

Details on test solutions:

A stock solution of the test item was prepared by dissolving 100.2 mg of the test item in 1000 mL of test medium, resulting in a nominal concentration of 100 mg test item/L. This stock
solution was stirred for 20 min. The stock solution was clear, and used immediately to prepare the desired test item concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name, Strain/clone: Daphnia magna (Straus), clone M10
- Age of parental daphnids: Less than 35 days
- Age of the daphnids at the beginning of the test: Less than 24 hours
- Feeding during test: none

ACCLIMATION
- Acclimation conditions: same as test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

254 mg/L CaCO3

Test temperature:

18-22°C

pH:

7.6-7.7

Dissolved oxygen:

93-99% Dissolved Oxygen

Conductivity:

663 μS/cm

Nominal and measured concentrations:

0, 6.25 12.5, 25, 50.0 and 100 mg/L (nominal concentrations based on the results of a preliminary non-GLP range finding test).

Details on test conditions:

TEST SYSTEM
- Test vessel: 50–60 mL
- Type (delete if not applicable): open
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4



TEST MEDIUM / WATER PARAMETERS
Test medium: Medium M4 (OECD 2004)
Temperature (target): 18–22°C, constant within a range of 2°C

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16 hours light : 8 hours dark
- Light intensity: 50–1000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
At start of the test, after temperature adaptation of the test solutions, and at the end of the test, the following parameters were measured and recorded in one replicate test vessel of the
control and the highest test concentration: temperature, pH and dissolved oxygen content in % of air saturation value (ASV) and in mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

88.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

Analytical results: see table 1
the % of recovery of the measured concentrations ranged from 77.6 to 110%, The measured test item concentrations were not stable between 80 and 120% of nominal concentrations during the test period.
The mean % of nominal concentrations was 93.5%.


Biological results: see Table 2
A clear concentration-response relationship was observed.
The EC50 was 94.3 mg/L at 48 hours exposure based on the nominal concentrations.
The EC50 based on measured concentrations was 88.2 mg/L as calculated by correcting the EC50 based on nominal concentrations by the factor of 0.935.

Results with reference substance (positive control):

The most recent reference test with potassium dichromate performed in a separate study resulted in an EC50(24 h) of 1.29 mg/L. According to the OECD guideline No. 202 (OECD, April 2004) EC50(24 h)-values for potassium dichromate obtained from different laboratories should range between 0.6 mg/L and 2.1 mg/L.

Reported statistics and error estimates:

Mortality as assessed by immobility of the daphnids was evaluated. Weibull analysis using linear maximum likelihood regression was used to estimate the ECx values.The geometric mean of the measured concentrations of the fresh and aged test solutions was calculated as the squareroot of the product of fresh and aged concentration of a given treatment level.

 Table 1: Summary of measured concentrations during the test.

 

Nominal concentration [mg test item/L]	Measured concentration [mg test item/L] at 0 hours	Measured concentration [mg test item/L] at 48 hours	Geometric mean measured concentration [mg test item/L]	% of nominal concentration	mean % of nominal
6.25	6.10	3.85	4.85	77.6	93.5
25	32.1	23.8	27.6	110
100	94.5	91.3	92.8	92.9

Table 2 :Cumulative number of immobile Daphnia magna after 24 and 48 h.

 

Nominal concentration [mg test item/L]	Total number of introduced daphnids	Total number of immobile daphnids 24h	Immobile daphnids (% of introduced) 24h	Total number of immobile daphnids 48h	Immobile daphnids (% of introduced) 48h
Control	20	0	0	0	0
6.25	20	0	0	0	0
12.5	20	1	5	1	5
25.0	20	0	0	1	5
50.0	20	1	5	1	5
100	20	12	60	12	60

 

Validity criteria fulfilled:

yes

Conclusions:

A clear concentration-response relationship was observed.
The EC50 was 94.3 mg/L at 48 hours exposure based on the nominal concentrations.
The EC50 based on measured concentrations was 88.2 mg/L as calculated by correcting the EC50 based on nominal concentrations by the factor of 0.935.

Executive summary:

The effect of the test item on the mobility of species Daphnia magna was investigated in a 48‑hour static test according to the OECD Guidelines for Testing of Chemicals (April 2004) No 202,"Daphnia sp., Acute Immobilisation Test”. The study was compliant with the GLP.

 

Based on a preliminary range-finding test, twenty daphnids were exposed to the test item over a range of nominal concentrations of 6.25, 12.5, 25.0, 50.0 and 100 mg test item/L and control for 48 hours at a temperature of approximately 21°C under static test conditions. The 20 daphnids per test solution, divided into four replicates of 5 daphnids each, were observed for immobility after 24 and 48 hours of exposure.

The test solutions were analysed to determine actual levels of the test item in comparison to the nominal concentrations at start and at end of the test.

The mean % of nominal concentrations was 93.5%. The biological endpoints are therefore expressed based on nominal and geometric mean measured concentrations. 

 A clear concentration-response relationship was observed.

The EC50 was 94.3 mg/L at 48 hours exposure based on the nominal concentrations equivalent to 88.2 mg/L based geometric mean measured concentrations (correcting the EC50 based on nominal concentrations by the factor of 0.935).

 

The two validity criteria of the OECD guideline 202 were fulfilled, therefore this study is considered as reliable without restrictions.

Description of key information

The toxicity of the Reaction mass of diethyl adipate and diethyl glutarate and diethyl succinate to the freshwater flea Daphnia magna was investigated in a GLP-compliant study performed in accordance with OECD Guideline No. 202.

Under the conditions of the study, the 48h-EC50 was 94.3 mg/L based on the nominal concentrations corresponding to 88.2 mg/L based geometric mean measured concentrations (correcting the EC50 based on nominal concentrations by the factor of 0.935).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

88.2 mg/L

Additional information

The toxicity of the test item to freshwater flea Daphnia magna was investigated in one GLP-compliant study performed in accordance with standard methods, without deviation. The study is considered as reliable (Klimisch 1) and is selected as a key study for the endpoint.