Zinc dodecyl hydrogen disulphate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

23 Oct - 24 Nov 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Aerobic sludge originating from the mixed treatment plant of urban (66%) and industrial (34%) liquid sewage situated at San Rocco-Monza (MI).
- Preparation of inoculum for exposure: in the laboratory, the sampled sludge was mixed and let to settle in aerobic conditions. Before use, the sludge was cenfrifuged, washed and alaysed for the concentration of suspended solids.
The concentration of suspended solids was about 4 mg/L.

Duration of test (contact time):

28 d

Initial conc.:

20.4 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

inorg. C analysis

Details on study design:

TEST CONDITIONS
- Composition of medium:
Solution A:
KH2PO4: 8.5 g/L
K2HPO4: 21.75 g/L
Na2HPO4 x 2H2O: 33.4 g/L
NH4Cl: 0.5 g/L

Solution B:
CaCl2 x 2H2O: 36.4 g/L

Solution C:
MgSO4 x 7H2O: 22.5 g/L

Solution D:
FeCl3 x 6H2O: 0.25 g/L

10 mL of Solution A was mixed with 800 mL of deionised water. 1 mL of Solution B, C and D was added. The deionised water was finally added up to 1000 mL volume.

- Test temperature: 25°C ± 2°C
- pH adjusted: no
- Aeration of dilution water: no
- Suspended solids concentration: 4 mg/L
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: glass bottles with hermetic seal
- Number of culture flasks/concentration: 5
- Measuring equipment: automatic TOC analyser (SHIMADZU).

SAMPLING
- Sampling frequency: weekly

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 5 bottles
- Abiotic sterile control: no
- Toxicity control: yes, 5 bottles

Reference substance:

benzoic acid, sodium salt

Remarks:

concentration 20.1 mg/L (TOC)

Key result

Parameter:

% degradation (inorg. C analysis)

Value:

91

Sampling time:

28 d

Results with reference substance:

biodegradation of 114% after 28 days

Biodegradation of the reference substance and test substance:

Day	% biodegradation reference substance	% biodegradation test substance
0	0	0
1	49	9
7	100	66
14	100	77
21	109	82
28	114	91

Validity criteria fulfilled:

yes

Interpretation of results:

other: biodegradable

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

14 Jul - 11 Aug 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Remarks:

Test was a inner test performed in our lab as screening. We are not an external lab GLP certified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: clarification plant Niederlahnstein
- Storage conditions: not stated
- Preparation of inoculum for exposure: not stated
- Concentration of sludge: 29.7 mg/L

Duration of test (contact time):

28 d

Initial conc.:

108.6 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

radiochem. meas.

Details on study design:

TEST CONDITIONS
- Composition of medium: not stated
- Test temperature: not stated

TEST SYSTEM
- Culturing apparatus: not stated
- Number of culture flasks/concentration: not stated


SAMPLING
- Sampling frequency: daily

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

89

Sampling time:

28 d

Results with reference substance:

97% after 28 days

Biodegradation results:

Day	Biodegradation %
	Test substance	Reference substance
1	25	19
2	47	41
3	56	58
4	55	66
5	62	70
6	65	74
7	67	77
8	69	80
9	71	82
10	72	84
11	73	85
12	75	87
13	76	87
14	78	88
15	80	89
16	80	89
17	81	90
18	81	90
19	81	91
20	82	91
21	84	93
22	82	93
23	84	94
24	88	95
25	87	96
26	89	96
27	89	96
28	89	97

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

15 Dec 1995 -12 Jan 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

1996, 27th February, The Department of Health of the Government of the United Kingdom

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Sewage treatment plant Hochdahl (1mL/L culture solution)

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

act. ingr.

Initial conc.:

5 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 20 ± 1 °C
- Continuous darkness: yes

SAMPLING
- Sampling frequency: Day 0, day 7, day 21 and day 28

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

> 90 - < 100

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Refer to the Analogue Approach Justification document provided in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Parameter:

% degradation (O2 consumption)

Value:

> 90 - < 100

Sampling time:

28 d

Remarks on result:

other: CAS 85586-07-8

Description of key information

Readily biodegradable(WoE approach)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Ready biodegradation of C12-14 AS Zn is assessed based on weight of evidence approach. Two reliable studies investigating ready biodegradation of C12-14 AS Zn are available. The first GLP study (Z&S, 2014) was performed according to OECD 301B guideline. Activated sludge originated from a mixed treatment plant of urban and industrial liquid sewage. The test was carried out with the concentration of the test substance 20 mg/L TOC. The biodegradation reached 91% after 28 days and therefore the substance can be considered as biodegradable. The second non-GLP study (Z&S, 2009) was conducted according to OECD 301F guideline. Activated sludge from sewage treatment plant was used as inoculum. Oxygen consumption was followed by 28 days. At the end of the test biodegradation rate of 89% was reached. The test item is considered to be readily biodegradable.

Moreover, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5, a read-across to a structurally related substance C12-14 AS Na (CAS 85586-07-8) was conducted. A GLP study was performed according to OECD guideline 301 D (BASF, 1996). Activated, non-adapted domestic sludge was used as inoculum. The biodegradation after 28 days reached >90% (as O2 consumption) and the substance was considered as readily biodegradable.

In general, ready biodegradability tests are available for several substances belonging to the category of alkyl sulfates. Based on the results of screening tests it can be concluded that alkyl sulfates with carbon chain length of C8-C20 are readily biodegradable according to OECD criteria (OECD, 2007; HERA, 2002).

Based on the available evidence, it can be concluded that C12-14 AS Zn is readily biodegradable according to OECD criteria.