2-Propanol, 1-amino-, compds. with polyethylene glycol hydrogen sulfate C12-14-alkyl ethers

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 MAR - 15 MAR 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Two stock solutions were prepared
Concentrations stock solution 1: 13.1165 g/L
Concentrations stock solution 2: 9.8377 g/L

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Preparation of inoculum for exposure: before the batches were inoculated, the extinction of the bacterial preliminary culture solution was measured and this was diluted with test culture nutrient medium to an extinction of 0.15 approximately (original bacterial suspension: extinction 0.152 at 436 nm.
- Initial biomass concentration: extinction 0.15

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

17 h

Remarks on exposure duration:

approximately

Test temperature:

21.7 °C

pH:

7.2 - 8.3

Nominal and measured concentrations:

nominal: 1250, 2500, 3750, 5000, 7500, 10000 mg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size: sterile 250 mL Erlenmeyer flasks, plugged with cotton wool
- No. of vessels per concentration (replicates): 3 parallels for each of the 6 test substance batches
- No. of vessels per control (replicates): 6 growth controls, 6 control batches, 1 pH control for each of the 6 test substance batches.

Reference substance (positive control):

no

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth inhibition

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth inhibition

Concentration [mg a.s./L]	Extinction mean values at 436 nm	Inhibition (%)
Control^*	1.660	--
1250	1.686	-1.6
2500	1.646	0.9
3750	1.687	-1.6
5000	1.656	0.3
7500	1.588	4.4
10000	1.572	5.4

^*cell multiplication: 1.644

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 SEP - 01 OCT 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data based on the inhibition control of a ready biodegradability study.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 20 mg/I organic carbon reference substance (sodium benzoate) and 20 mg/L organic carbon of the test item were added directly into the vessel

Test organisms (species):

activated sludge

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

21.0 °C - 22.1 °C

Nominal and measured concentrations:

Nominal test substance concentration: 55.5 mg/L

Details on test conditions:

TEST CONDITIONS
- Composition of medium: Solution A: KH2PO4: 8.50 g, K2HPO4: 21.75 g, Na2HPO4 x 2H2O: 33.40 g, NH4Cl: 0.50 g; Solution B: CaCl2 x 2H2O: 36.4 g; Solution C: MgSO4 x 7H2O: 22.50 g; Solution D: FeCl3 x 6H2O: 0.25 g. For preparation of the mineral medium 10 mL of solution A is mixed with 800 mL demineralised water, 1 mL of solutions B, C and D are added and made up to 1 litre each.
- Aeration of dilution water: aeration with CO2-free air at a rate of 50 - 100 mL/min
- Suspended solids concentration: dry solids of the acitvated sludge was determined as 2.96 g/L by weight measurements after 2 h drying at 105 °C (mean of triplicate measurements)


TEST SYSTEM
- Culturing apparatus: gas wash bottles (2000 mL volume) with lateral connecting pieces for butyl rubber septums were used as reactors.
- Number of culture flasks/concentration: 3
- Measuring equipment:
- Details of trap for CO2 and volatile organics if used: CO2-absorption medium: 72 g NaOH were dissolved in 9000 mL deionised water in closed recipients (0.2 M NaOH).
- Other: the CO2-free air production system consists of an air compressor, two 1000 mL gas wash bottles filled with dry soda lime, followed by one bottle filled with 0.1 M NaOH. At the end of the system was one gas wash bottle filled with demineralised water, followed by an empty one to catch any drops of condensation water. A colour range of the soda lime from white to blue indicates, that CO2 absorption capacity is depeted. The CO2-free air is passed on to an air distributer with two imput and 22 output channels and through PE-tubes.


SAMPLING
- Sampling frequency: 4, 7, 11, 14, 21 and 28 days
- Sampling method: sampling was performed through the lateral connecting pieces through the butyl rubber septum using 5 mL PE syrings.


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes - 3 replicates
- Toxicity control: yes - 1 replicate containing test item and reference compound (concentration: 40 mg/L organic carbon)

Reference substance (positive control):

yes

Remarks:

sodium benzoate

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

55.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: CO2 evolution

Remarks:

Result of toxicity control from ready biodegradability test

Details on results:

The degradation in the toxicity control was 99.4% after 14 days and 100.7 after 28 days.

Results with reference substance (positive control):

The reference substance was degraded by 90.267% after 14 days.

Table 1 Biodegradation

	0 d	4 d	7 d	11 d	14 d	21 d	28 d	28 d (after acidification)
Reference	0	54.5	72.7	84.4	84.9	91.1	91.2	92.2
Reference	0	32.4	72.2	83.8	86.7	93.2	94.8	101.5
Reference	0	67.2	87.7	98.0	99.2	97.2	98.7	96.3
Toxicity control	0	59.1	74.8	89.8	99.4	98.5	95.6	100.7
blank	0	8.8	18.1	20.1	24.9	29.2	29.1	30.1

Validity criteria fulfilled:

not specified

Description of key information

The effect of the target substance on the growth of Pseudomonas putida was investigated in a GLP guideline study according to DIN 38412, part 8. An EC10 > 10 g/L were determined after an exposure time of 16 hours. The findings are supported by the results of an inhibition control of the available biodegradation screening study (OECD 301 B). No inhibition of the activated sludge organisms was observed and a NOEC (14 d) of 55.5 mg/L (based on CO2 evolution of activated sludge organisms) was determined.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

10 000 mg/L

Additional information

The toxicity of the alkyl ether sulfates (AES) substances to microorganisms was assessed by read-across based on the grouping of substances (category approach). All data on toxicity to microorganisms available for the category were used to assess the toxicity of category substances to microorganisms. The available data indicate no adverse effects of alkyl ether sulfates on microbial activity. All substances of the alkyl ether sulfates category are considered readily biodegradable. In the available screening studies including a toxicity control, no inhibition of the degradation process by the test substance was observed. The available studies investigating the respiration inhibition of activated sludge organisms and Pseudomonas putida determined no detrimental effects of the tested alkyl ether sulfates.