[2-(1-ethoxyethoxy)ethyl]benzene

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 - 25 May 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

pooled samples, limited number of replicates, CoA lacking, pH and temp only reported for 48h

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

not specified

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Test concentrations were verified by chemical analysis at t=0 and t=48 h.
Analysis of all test concentrations plus a control at test start and after 48 hours of exposure (after 24 hours of exposure because of early 100% immobilization rates).

Vehicle:

no

Details on test solutions:

To produce the stock solution (120 mg/L) the test substance was weighed into water, treated for 60 seconds at 8000 rpm. with an ultraturrax and afterwards stirred an a magnetic stirrer for 24 hours. To remove undissolved particles, the resulting emulsion was filtered using a folded filter of the pore size 7-12 um. Final volume of test solution 20 mL, dilution water used was M4-Medium according to Elendt and BGA (1992).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
Daphnia magna STRAUS, (parthenogenetic females)
- Source: cloned at the Federal Health Office (BGA) in Berlin
- Age at study initiation (mean and range, SD): 0-24 h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

15.6 dH

Test temperature:

48h: 20.1 - 20.3°C

pH:

48h: 7.9

Dissolved oxygen:

48h: 8.3-8.6 mgO2/L

Nominal and measured concentrations:

nominal conc: 0, 6.3, 12.5, 25, 50, 100 mg/L
measured TOC t=0h: < 2, 5, 8, 19, 37, 73 mg/L
measured TOC t= 48h: < 2, 4, 8, 18, 32, 71 mg/L
arithmetic means: <2, 4.5, 8, 18.5, 34.5, 72 mg/L

Details on test conditions:

- 16 hours light/8 hours dark,
- cylindrical test vessels diameter 4.0 cm, height 6.5 cm
- 20 ml test medium
- not ventilated

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

15.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results are based on pooled samples

Remarks:

Confidence interval is: 7.8 - 23.4 mg/L

Details on results:

Measured concentrations ranged from 83 - 103 % of nominal at 0 hours and 83 - 94 % of nominal at 48 hours. The measured concentrations of the test substance after 48 hours were in range of 80-100% compared to the initial measured concentrations at t=0 hrs.

Cumulative immobilisation data for Daphnia magna exposed for 48h to the test substance

Nominal conc (mg/L)	arithmetic mean measured conc (mg/L)	24h total immobilisation #	24h total immobilisation %	48h total immobilisation #	48h total immobilisation %
Control	Control	0	0	0	0
6.3	5.85	0	0	0	0
12.5	10.40	0	0	5	25
25	24.05	14	70	16	80
50	44.85	16	80	16	80
100	93.60	20	100	20	100

Validity criteria fulfilled:

not specified

Conclusions:

The 48h EC50 of the substance is 15.6 mg/L.

Executive summary:

A study was performed to assess the acute toxicity of the substance to Daphnia magna. The study was conducted in accordance with EU Guideline C.2 (1992), but assigned Klimisch 2 because of methodological limitations (pooled samples, limited number of replicates (two), pH and temp only reported for 48h), which however are not considered to have influenced the study results. Groups of twenty Daphnia (less than 24 hours old) were exposed for 48 hours to 5 concentrations (nominally 6.3, 12.5, 25, 50, 100 mg/L) of the substance dispersed in test water. The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours and the test concentrations were measured by TOC. This is considered acceptable because the substance is expected to be fairly stable at pH 7 (only under acidic conditions acetals can hydrolyse). Results are expressed in terms of measured (arithmetic mean) concentration. Measured concentrations ranged from 83 - 103 % of nominal at 0 hours and 83 - 94 % of nominal at 48 hours. The EC50 was determined to be 15.6 (95% confidence interval: 7.8 -23.4 mg/L).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The result derived from read across

Justification for type of information:

The read across justification for Daphnia and algae is presented in the Endpoint summary for Aquatic toxicity and the accompanying files are also attached there.

Reason / purpose for cross-reference:

read-across source

Water media type:

freshwater

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

15.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results are based on pooled samples

Remarks:

Confidence interval is: 7.8 - 23.4 mg/L

Validity criteria fulfilled:

yes

Remarks:

adequate and reliable documentation on the read across is provided

Conclusions:

The 48h EC50 is 15.6 mg/L, based on read-across from Hyacinth body.

Description of key information

The 48h EC50 is 15.6 mg/L, based on read across from Hyacinth body #3.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

15.6 mg/L

Additional information

For Hyacinth body read across from Hyacinth body #3 was applied. Read-across justification is added in the endpoint summary of Aquatic toxicity because also the algae toxicity is presented there. Below the experimental results for Hyacinth body #3 are presented.

Daphnia toxicity study with Hyacinth body #3

A study was performed to assess the acute toxicity of the substance to Daphnia magna. The study was conducted in accordance with EU Guideline C.2 (1992), but assigned Klimisch 2 because of methodological limitations (pooled samples, limited number of replicates (two), pH and temp only reported for 48h), which however are not considered to have influenced the study results. Groups of twenty Daphnia (less than 24 hours old) were exposed for 48 hours to 5 concentrations (nominally 6.3, 12.5, 25, 50, 100 mg/L) of the substance dispersed in test water. The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours and the test concentrations were measured by TOC. This is considered acceptable because the substance is expected to be fairly stable at pH 7 (only under acidic conditions acetals can hydrolyse). Results are expressed in terms of measured (arithmetic mean) concentration. Measured concentrations ranged from 83 - 103 % of nominal at 0 hours and 83 - 94 % of nominal at 48 hours. The EC50 was determined to be 15.6 (95% confidence interval: 7.8 -23.4 mg/L).