Undecyl glucoside

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 Feb - 18 Mar 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data based on the inhibition control of 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 2012).

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium fur Umwelt, ländlichen Raum und Verbraucherschutz, Wiesbaden, Germany

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Preparation: 24.7 mg test item + 24.3 mg reference item + 5 mL activated sludge + 239 mL test water (244 mL final volume)

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source of inoculum/activated sludge: sewage plant Darmstadt Germany
- Preparation of inoculum for exposure: the aerobic activated sludge was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again. The procedure was repeated 3 times. The sediment was re-suspended in test water and aerated for 2 d. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to dry weight was determined. Based on this ratio, aliquots of 1.5 g dry material/L were mixed with test water. This suspension was used for the experiment.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

28 d

Test temperature:

22 °C (test flasks were incubated in a climatised room)

pH:

7.6 (measured at the start of the test), 6.9-7.7 (measured at the end of the test)

Nominal and measured concentrations:

96 mg/L based on ThODNH4

Details on test conditions:

TEST SYSTEM
- Test vessel: Manometric Test System with test flask containing a volume of approx. 500 mL (BSB Seonsomat system, Aqualytic Langen)
- No. of vessels per concentration (replicates): 2
- No. of vessels per inoculum control (replicates): 2
- No. of vessels per procedure control (replicates): 1
- Abiotic sterile control: 1 replicate, sludge poisoned with HgCl2 (stock solution of 48.84 mg/mL)
- Test performed in closed vessels: yes
- Details of trap for CO2: potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide
- Other: a correction for potential uptake of oxygen by nitrification was considered. Therefore, analysis of nitrate and nitrite using ion chromatography was conducted (Dionex DX 120 ion chromatography system - UV detector UVD 340s and AS 50 Autosampler, wavelength: 225 nm, column: IonPac AS4 A-SC 4 mm x 250 mm, eluent: 15 mmol/L KCl in deionised water, eluent flow: 1.5 mL/min, temperature: 10 - 30 °C)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline
- Intervals of water quality measurement: temperature was measured every day. pH was measured in controls at the beginning and in all flasks at the end of the test.

OTHER TEST CONDITIONS
- Photoperiod: continuous darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :pressure decrease in the reaction vessels was measured every day over the 28 d test period

Reference substance (positive control):

yes

Remarks:

sodium benzoate, loading rate of 102 mg/L, corresponding to an oxygen demand of about 170 mg/L [ThOD(NH4)]

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

96 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: ThOD(NH4)

Basis for effect:

other: COD

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

102 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: COD

Results with reference substance (positive control):

88% biodegradation after 14 d and to a mean of 92% after 28 d of incubation.

78% biodegradation of sodium benzoate in the toxicity control after 14 d and 85% within 28 d based on ThOD(NH4). The test substance is assumed to be not inhibitory to the aerobic activated sludge microorganisms.

Table 1: Cumulative Biochemical Oxygen Demand (mg O2/L) in the toxicity control during the test period of 28 d

Time [d]	Toxicity control [%]
1	19
2	29
3	49
4	56
5	59
6	63
7	65
8	67
9	69
10	71
11	73
12	75
13	76
14	78
15	79
16	79
17	81
18	82
19	83
20	83
21	83
22	84
23	84
24	85
25	85
26	85
27	85
28	85
21	83
22	84
23	84
24	85
25	85
26	85
27	85
28	85

Table 2: % biodegradation of the toxicity control based on ThODNH4

Time [d]	Toxicity control [%]
1	19
2	29
3	49
4	56
5	59
6	63
7	65
8	67
9	69
10	71
11	73
12	75
13	76
14	78
15	79
16	79
17	81
18	82
19	83
20	83
21	83
22	84
23	84
24	85
25	85
26	85
27	85
28	85

Description of key information

NOEC (28 d) > 102 mg/L (nominal, OECD 301 F)

Additional information

No studies investigating the toxicity of D-Glucopyranose, oligomeric, undecyl glycoside (CAS 98283-67-1) to microorganisms are available. However, a toxicity control was performed in the study testing the ready biodegradability (Ibacon GmbH, 2008). These results were used to assess the endpoint `toxicity to microorganisms´. A treatment containing the test item at a concentration of 96 mg/L and sodium benzoate, as a reference substance, at 170 mg/L (both concentrations based on ThOD(NH4)), was inoculated with sewage sludge microorganisms and incubated for 28 d. 88% biodegradation was noted within 14 d based on O2 consumption. Thus, the test item can be assumed to be not inhibitory up to the tested concentration to the activated sludge microorganisms (NOEC (28 d) ≥102 mg/L).