3,6,9,12-tetraoxahexadecan-1-ol

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source substance triethylene glycol butyl ether (TEGBE) is adjacent to the target substance TetraEGBE in the E series butyl glycol ether homologous series. Based on a reliable QSAR (ECOSAR) for other aquatic toxicity end points, the toxicity to aquatic species is expected to decrease with increasing molecular weight of the homologous series, using TEGBE as a surrogate to estimate the toxicity of TetraEGBE should be conservative approach.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source: Triethylene glycol butyl ether
Target: Ttetraethylene glycol butyl ether.
Impurities: Both the source and target substances will contain the same impurities as they are produced in the same process, therefore they will have similar impurity profiles and impurities will not impact on the validity of the read across. Indeed both would contain the other as an impurity.

3. ANALOGUE APPROACH JUSTIFICATION
See hypothesis above. TEGBE is expected to be more toxic than TetraEGBE therefore using data from studies using pure TEGBE to estimate the toxicity of TetraEGBE will be a conservative approach

4. DATA MATRIX

QSAR information below shows how toxicity increases with decreasing molecular weight for the other aquatic toxicity end points. The same trend is expected with micro-organisms (mode of action is non specific narcosis) therefore using TEGBE data directly should be conservative.
TEGBE TetraEGBE
Fish LC50 (g/L) 10 22
Daphnia EC50 (g/L 4.8 10
Algae EC50 (g/L) 1.7 3.2

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Very basic information only available. Likely to be sufficiently reliable only when used in a weight of evidence approach.

Qualifier:

no guideline followed

Principles of method if other than guideline:

According to the test method published in: Alsop et al., "Bacterial Growth Inhibition Tests", J. Water Pollution Control Federation, Vol 52: No. 10, October, 1980.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge

Test type:

not specified

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

16 h

Duration:

16 h

Dose descriptor:

IC50

Effect conc.:

> 5 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Validity criteria fulfilled:

not specified

Executive summary:

In a bacterial growth inhibition study using sewage micro-organisms for which only basic details are available, the IC50 was found to be greater than 5000mg/l.

Cross-reference 2

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

not specified

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge, industrial

Details on inoculum:

- Activated sludge from the BASF wastewater treatment plant
- Final dry solids concentration: 1 g/L

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Details on test conditions:

Nominal test concentrations: 1.5, 300, 1995 mg/L

Reference substance (positive control):

not specified

Duration:

30 min

Dose descriptor:

EC10

Effect conc.:

> 1 995 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

- No inhibition of respiration was observed up to a concentration of 1995 mg/L.
- The test substance caused an increased bacterial ceIl multiplication in the concentration range of 300 - 1995 mg/L (max. 88 % compared to the control).

Executive summary:

In a guideline activated sludge respiration inhibition test using 2-(2-(2-butoxyethoxy)ethoxy)ethanol, no effects were observed up to the maximum tested concentration of 1995mg/l.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

3,6,9,12-tetraoxahexadecan-1-ol

EC Number:

216-322-1

EC Name:

3,6,9,12-tetraoxahexadecan-1-ol

Cas Number:

1559-34-8

Molecular formula:

C12H26O5

IUPAC Name:

3,6,9,12-tetraoxahexadecan-1-ol

Test material form:

liquid

Results and discussion

Effect concentrations

Duration:

30 min

Dose descriptor:

EC10

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: not determinable due to no adverse effects being seen at maximum tested dose of 1995 mg/L