Reaction mass of 1-Hydroxyoctane, 2-methanoate and 1,2-Dihydroxyoctane, dimethanoate and 2-Hydroxyoctane 1-methanoate and 1,2-Dihydroxyoctane

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 Mar - 28 Apr 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Qualifier:

according to guideline

Guideline:

other: EU Commission Directive 92/69/EEC, Part C.6 following DIN 38414-S9

Version / remarks:

Determination of COD of test item due to complex composition

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office for the Environment (FOEN)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): treatment plant, ARA Birs (Birsfelden / Switzerland)
- Preparation of inoculum for exposure: prior to use, dry weight was determined. Sludge was then diluted 1:4 with mineral medium. Based on this dry weight determination definited amounts of the diluted activated sludge were added to the mineral medium in the test vessels.
- Pretreatment: washed twice by centrifugation, resuspension of the solid material in tap water and finally in mineralmedium. After derermination of the dry weight, 4 g/L wet sludge were suspended in mineral medium, hold 2 d (with aeration and RT)
- Water filtered: no

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Initial conc.:

180 mg/L

Based on:

COD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Solubilising agent (type and concentration if used): no
- Test temperature: 22-23 °C
- pH: 7.3 - 7.9
- Suspended solids concentration: 30 mg d.w./L
- Light conditions: diffused lighting

TEST SYSTEM
- Culturing apparatus: 500 mL GL45 laboratory glass bottles with 164 mL test suspension. Test vessels were air-tight closed with the OxiTop measuring heads.
- Number of culture flasks/concentration: 2
- Measuring equipment: OxiTop measuring heads
- Test performed in closed vessels due to significant volatility of test substance: yes
- Test performed in open system: no

SAMPLING
- Sampling frequency and method: BOD values automatically recorded every 3 h

CONTROL AND BLANK SYSTEM
- Inoculum control: 2 vessels
- Reference control: 2 vessels
- Toxicity control: 1 vessel

Reference substance:

benzoic acid, sodium salt

Remarks:

ThOD of 1.67 mg O2/mg

Key result

Parameter:

% degradation (O2 consumption)

Value:

104

Sampling time:

28 d

Details on results:

- 10 day window passed
- Biodegradation in toxicity control: 74% after 14 d and 97% at day 28

Parameter:

COD

Value:

1.8 mg O2/g test mat.

Results with reference substance:

Biodegradation:
- 63% on day 3
- 86% on day 14
- 90% on day 28

Table 1: Biodegradation of the Test Item and the Reference Item.

	% Biodegradation
	Test item		Procedure control		Toxicity control
	Replicate No.		Replicate No.		Replicate No.
Time [days]	1	2	1	2
1	4	3	16	17	13
2	26	25	52	51	29
12	93	93	87	84	70
14	96	96	88	85	74
28	105	103	92	87	97

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item was found to be completely and readily biodegradable after 28 days of exposure to activated sludge under the conditions of the conducted Manometric Respirometry Test according to OECD 301 F.

Description of key information

Readily biodegradable: 104% after 28 d (O2 consumption, OECD 301F)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

One experimental study is available investigating the ready biodegradability of the substance. The study was performed according to OECD 301F and GLP. Activated sludge from a domestic sewage treatment plant was used as inoculum and was exposed to 100 mg/L test material. 104% degradation of the substance was recorded based on O2 consumption after 28 d. The 10-day window criterion was fulfilled. Thus, the substance is readily biodegradable according to the OECD criteria under the chosen test conditions. A toxicity control containing both, reference substance and test substance, did not indicate inhibitory effects of the substance to the inoculum (86% degradation within 14 d and 90% degradation after 28 d).