(ethylenedioxy)dimethanol

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:

2000

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)

Version / remarks:

Part I (1984)

Deviations:

yes

Remarks:

Test period 48 h instead of 24 h as proposed in the OECD Guideline. The test temperature was not within the range proposed by the guideline. It is expected that this deviation does not significantly influence the results obtained.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

TS in samples of nominal concentrations of 20, 40 and 80 mg/L measured at the beginning and after 48 h.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Source: Laboratory breed. Cultivation according to SOP S001 of Institute Fresenius Taunusstein
- Age of parental stock: ≤ 24 h
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.0 – 22.5°C

pH:

7.10 – 7.63

Dissolved oxygen:

7.3 – 8.2 mg/L

Nominal and measured concentrations:

Nominal concentrations:
Screening test: 0.1, 1.0, 10, 100 mg/L
Main test: 100, 80, 40, 20, 10 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 290 mL
- Type: closed
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- Biomass loading rate: 58 mL/animal

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dilution water according to DIN 38412, part 11
- Intervals of water quality measurement: pH measured at beginning of the test and after 48 h.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light/dark cycle : 16 h / 8 h

EFFECT PARAMETERS MEASURED :
Immobility (no swimming within 15 sec.). After 48 h numbers of immobilized daphnia were recorded.

Reference substance (positive control):

yes

Remarks:

The toxicity to the reference substance (Potassium dichromate) is tested once a month.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

28 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 d

Dose descriptor:

EC50

Effect conc.:

28 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Other adverse effects control: none

Results with reference substance (positive control):

Within the monthly period, an EC50 (24h) of 1.2 mg/L potassium dichromate was determined.

Reported statistics and error estimates:

Validated computer program on the basis of EXCEL 5.0 used for calculation of EC-values only at time t(24h) and not for t(48h), as there was no concentration-effect relation over 5 concentrations.

Determination ofthe test substance in the test medium:

Sampling time [h]	Nominal Conc. [mg/L]	Measured Conc. [mg/L]
0	20	19.54
0	40	37.40
0	80	77.52
0	control	< 2
48	20	19.23
48	40	37.60
48	80	76.85

The results in the table were not corrected by the recoveries obtained for the analytical method. A mean recovery of 101% was determined.

The test solutions showed no significant loss of the test substance. Therefore, nominal concentrations can be considered as effective concentrations.

Results of main test:

Test substance Concentration (nominal) [mg/L]
	ImmobileDaphnia
	Number		Percentage		O2 [mg/l] 48 h	pH   48 h	Temp. [°C] 48 h
	24 h	48 h	24 h	48 h
Control			0	0	7.3	7.19	20.4
100			100	100	7.5	7.44	20.1
80			100	100	8.2	7.61	20.1
40			50	100	7.8	7.63	20.0
20			0	0	8.0	7.55	20.0
10			0	0	7.7	7.48	20.1

During the test period, the temperature (measured at 0 h and 48 h) was within a total range stretching from 20.0 to 22.5 °C and varied in some single vessels by up to 2.4°C.

Results of main test:

	EC50	95 % c.l.	EC0	EC100
24 h [mg/L]	28	No data	20	80
48 h [mg/L]	28		20	40

nominal concentrations

EC₀ and E₁₀₀ were directly taken from the concentrations being tested. E₅₀(48h) calculated as the geometric mean between E₀ and E₁₀₀.

Validity criteria fulfilled:

yes

Conclusions:

The EC50 was calculated as the geometric mean between EC0 and EC100 representing 28 mg/L of the test substance.

Executive summary:

EGForm was tested for acute toxicity towardsthe water flea Daphnia magna according to the OECD Guideline 201 part I.

The animals were exposed to 5 concentrations of the test substance, ranging from 10 to 100 mg/l, and a control group. The test was performed at 20.0 – 22.5 °C in a medium according to DIN 38412, part 11. Immobilisation was assessed at 24 and 48 hours, physico-chemical water parameters and formaldehyde concentrations were measured at the beginning and after 48 hours.

The test substance was found to be acutely harmful for Daphnia magna. All results refer to the nominal concentrations since the formaldehyde concentration was found stable within the incubation period.

A clear concentration-response relationship can be established from the study results. Lethal effects were observed at concentrations from 40 mg/L and above. Because of the steep concentration-effects curve after 48 h, the EC₅₀ was calculated as the geometric mean between EC₀ and EC₁₀₀ representing 28 mg/L of the test substance.

The test substance EGForm hydrolyses rapidly and completely in the test medium, forming ethylene glycol and formaldehyde. Formaldehyde is expected to dominate the toxicity of EGForm in aqueous solutions. Dissolved Formaldehyde is expected to be non-volatile, and no losses due to adsorption are to be expected.

Analysis of the formaldehyde concentrations during the test proved that no significant losses occurred. Therefore, the effective concentrations can be considered to be equal to the nominal concentrations.

During the test period, the temperature (measured at 0 h and 48 h) was within a total range stretching from 20.0 to 22.5 °C and varied in some single vessels by up to 2.4°C. According to the Guideline, the test temperature should range between 18 and 22 °C and remain constant within ±1°C in single tests. It is expected that this deviation does not signifcantly influence the results.

Description of key information

Acute toxicity towards invertebrates was tested with the water flea Daphnia magna. An EC50 (48h) of 28 mg/L was derived.

For ethylene glycol a 48 h EC50 value to Daphnia magna was determined to 46300 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

28 mg/L