Sodium formate

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: sewage treatment simulation testing

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

abstract

Qualifier:

according to guideline

Guideline:

OECD Guideline 303 A (Simulation Test - Aerobic Sewage Treatment. A: Activated Sludge Units)

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic (adaptation not specified)

Initial conc.:

10 mg/L

Based on:

DOC

% Degr.:

97.5

Parameter:

DOC removal

Sampling time:

3 h

Details on results:

The 97.5 % loss of DOC refers to an average retention time of 3 hours.

Reference 2

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 306 (Biodegradability in Seawater)

Deviations:

no

GLP compliance:

yes

Radiolabelling:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

other: non-specific marine microbiota (present in collected seawater, no cultured organisms added)

Details on source and properties of surface water:

- Details on collection (e.g. location, sampling depth, contamination history, procedure): seawater collected at NIVA's research station at Solbergstrand (Norway), 22 Oct 1998, 40 m depth, 26.8 ‰
- Storage conditions: seawater stored at 20 °C, gentle aeration
- Water filtered: no, coarse particles removed from seawater by sedimentation and decanting

Duration of test (contact time):

28 d

Initial conc.:

22.13 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Volume of test solution/treatment:
- Composition of medium: aged and decanted seawater, added mineral solutions according to guideline
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 20°C±2.4°C
- pH adjusted: no
- Continuous darkness: yes
- Any indication of the test material adsorbing to the walls of the test apparatus: no

TEST SYSTEM
- Culturing apparatus: closed bottle
- Number of culture flasks/concentration: 2
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: no

SAMPLING
- Sampling frequency: sampled on day 0, 5, 15, and 28
- oxygen measurements: day 0, 5, 15, and 28 with an oximeter

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Toxicity control: yes

Reference substance:

benzoic acid, sodium salt

% Degr.:

7

Parameter:

O2 consumption

Sampling time:

5 d

% Degr.:

74

Parameter:

O2 consumption

Sampling time:

15 d

Key result

% Degr.:

86

Parameter:

O2 consumption

Sampling time:

28 d

Transformation products:

not specified

Details on results:

- Activity in the reference control was satisfactory (> 50% after 5 days).
- Oxygen depletion in the blank did not exceed 30%.

Results with reference substance:

Kinetic of control substance (in %):
82 after 5 day(s)

Time	Biodegradation (% BOD of ThOD)
(days)	Na benzoate	Na formate	Inhibition control (Na formate + Na benzoate)
0	0	0	0
5	82	7	37
15	96	74	68
28	96	86	77

- Activity in the reference control was satisfactory (> 50% after 5 days).

- Oxygen depletion in the blank did not exceed 30%. 

Validity criteria fulfilled:

yes

Remarks:

The inoculum control was degraded by 82% within 5 days, therefore the inoculum activity was satisfactory. Moreover, oxygen depletion in the inoculum blank did not exceed 30% oxygen of the oxygen in the test bottle. The test is therefore considered valid.

Conclusions:

Sodium formate showed 86% biodegradation (ThOD) in seawater after 28 days (KM Lab, 1998).

Executive summary:

The marine biodegradability of sodium formate was investigated in an OECD 306 (biodegradability in seawater) study, the results of which showed 86% ThOD after 28 days (KM Lab, 1998).

Description of key information

Sodium formate is readily biodegradable (86% degradation, based on ThOD, over 28 days) (KM Lab, 1998).

In accordance with column 2 of REACH Annex IX, the study on simulation testing on ultimate degradation in surface water does not need to be conducted if the substance is readily biodegradable. Sodium formate is already tested to be readily biodegradable according to OECD criteria. Hence, no further testing on biodegradation e.g. in water or sediment is performed.