2-(2-ethoxyethoxy)ethyl acetate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Remarks:

Activated sludge O2 consumption

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 Jul - 20 Sep 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Data based on the result from a ready biodegradability study. This approach is in accordance with the Guidance on information requirements and chemical safety assessment (Chapter R.7b: Endpoint specific guidance, ECHA 2008).

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Circular on Test Methods of New Chemical Substances (Japan), Biodegradation test

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

other: mixture of activated sludge from STP with freshwater from rivers and lakes, marine water and marine sediment

Details on inoculum:

- Source of inoculum/activated sludge (location, sampling depth): location: 10 sites (4 sewage plants, 3 rivers, 1 lake and 2 bays) around Japan, sampling depth: return sludge in sewage plants, surface water and surface soil of foreshore
- Laboratory culture: Thirty minutes after stopping of aeration, discard about one third of the whole volume of supernatant and add an equal volume of a solution (pH adapted to 7.0 with NaOH) containing 0.1% each of glucose, peptone and potassium orthophosphate, to the settled material and re-commence aeration. This procedure was repeated once per day.
- Temperature: 25 ± 2 °C
- Storage conditions: observed appearance and general condition of sludge, determined sediments, pH, temperature and dissolved oxygen and observed with a light microscope, whether it is normal.
- Storage length: started to use: 16 Jul 1991
- Preparation of inoculum for exposure: Activated sludge from STP mixed with
- Concentration of sludge: 4600 mg/L
- Water filtered: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

28 d

Test temperature:

25 ± 1 °C

pH:

5.6 - 7.2

Nominal and measured concentrations:

nominal: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: closed oxygen consumption measuring machine with 300 mL culture bottle (coulometer)
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 1

EFFECT PARAMETERS MEASURED: biodegradation of the test substance based on BOD, TOC and GC-analysis

Reference substance (positive control):

no

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Result from ready biodegradability test

The initial inoculum concentration of 100 mg/L was degraded to an extend of 101% based on BOD, 95% based on TOC and 100% based on GC analysis. The substance is readily biodegradable according to the OECD criteria. Thus, the test substance is not considered to be inhibitory to activated sludge microorganisms.

Validity criteria fulfilled:

yes

Conclusions:

Toxicity to microorganisms was investigated in a biodegradation study according to OECD 301C. No inhibition of biodegradation was observed after 28 days and the tested concentration of 100 mg/L can be used as NOEC value for the toxicity to activated sludge microorganisms.

Executive summary:

The toxicity of 2-(2-ethoxyethoxy)ethyl acetate (CAS 112-15-2) to microorganisms was investigated in a biodegradation study according to OECD 301C. No inhibition of biodegradation was observed after 28 days and the tested concentration of 100 mg/L can be used as NOEC value for the toxicity to activated sludge microorganisms.

Description of key information

NOEC (28 d) ≥ 100 mg/L for activated sludge microorganisms (OECD 301C)

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

100 mg/L

Additional information

The toxicity of 2-(2-ethoxyethoxy)ethyl acetate (CAS 112-15-2) to microorganisms was investigated in a biodegradation study according to OECD 301C under GLP conditions (Ministry of Economy, Trade and Industry, Japan, 1991). The study was performed with a mixture of activated sludge from STP with freshwater from rivers and lakes, marine water and marine sediment. No inhibition of biodegradation was observed after 28 days. The test concentration from a biodegradation study which indicated that the test substance is readily biodegradable can be used to derive a NOEC for this endpoint as stated in the ECHA Guidance R.7b (ECHA, 2012). Therefore, the test item concentration of 100 mg/L can be used as NOEC value for the toxicity to activated sludge microorganisms. Thus a NOEC (28 d) of ≥ 100 mg/L resulted.