Bis(C12-C13)alkyl-2-hydroxybutandioate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May - July 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study without detailed documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): Cosmacol EMI
- Substance type: pure active substance
- Physical state: liquid
- Lot/batch No.: 2119

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Details on inoculum:

no data

Duration of test (contact time):

33 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

13.25 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

11.6 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

A measured volume of inoculated medium containing a known amount of test substance was stirred in a closed flask. The consumption of oxygen was determined from the reduction in volume of the air contained in the apparatus. Evolved CO2 was adsorbed in soda lime. The amount of oxygen taken up by the substance (corrected for blank) was expressed as a percentage of the theoretical oxygen demand calculated from the formula of the compound. A reference substance was run in parallel for checking the inoculum.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

73.8

Sampling time:

28 d

Details on results:

Points of degradation plot (test substance):
19.3 % degradation after 5 d
38.2 % degradation after 9 d
48.4 % degradation after 13 d
57.8 % degradation after 16 d
64.8 % degradation after 19 d
70.2 % degradation after 23 d
70.9 % degradation after 26 d
73.8 % degradation after 28 d
76 % degradation after 30 d
72.4 % degradation after 33 d

BOD5 / COD results

Results with reference substance:

Points of degradation plot (reference substance):
71.5 % degradation after 5 d
88.3 % degradation after 9 d
87.7 % degradation after 13 d
90.7 % degradation after 16 d
92.5 % degradation after 19 d
94.9 % degradation after 23 d
94.5 % degradation after 26 d
92.5 % degradation after 28 d
93.1 % degradation after 30 d
92.5 % degradation after 33 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The biodegradation of the test material Bis(C12-C13)alkyl-2-hydroxybutandioate measured by manometric repirometry was 77% after 28 days of incubation, approx. 48 % at the end of the 10-day window. Because the substance is an UVCB the 10-window has not to be fulfilled for being "readily biodegradable".

Executive summary:

Biodegradability of Bis(C12-C13)alkyl-2-hydroxybutandioate was assessed by mean of manometric respirometry according to OECD Guideline 301F.

A measured volume of inoculated medium containing a known amount of test substance was stirred in a closed flask. The consumption of oxygen was determined from the reduction in volume of the air contained in the apparatus. Evolved CO2 was adsorbed in soda lime. The amount of oxygen taken up by the substance (corrected for blank) was expressed as a percentage of the theoretical oxygen demand calculated from the formula of the compound. A reference substance (Sodium benzoate) was run in parallel for checking the inoculum.

The biodegradation of the test material Bis(C12-C13)alkyl-2-hydroxybutandioate measured by manometric repirometry was 77% after 28 days of incubation, approx. 48 % at the end of the 10-day window. Bis(C12-C13)alkyl-2-hydroxybutandioate was judged to be readily biodegradable, but failing the 10 -day window. Because the substance is an UVCB the 10-window has not to be fulfilled for being "readily biodegradable".