Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study in accordance to OECD GL

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1,1,3,3-pentachlorobutane
EC Number:
244-691-9
Cas Number:
21981-33-9
Molecular formula:
C4H5Cl5
IUPAC Name:
1,1,1,3,3-pentachlorobutane
Details on test material:
- Name of test material (as cited in study report): 1,1,1,3,3-pentachlorobutane
- Molecular formula (if other than submission substance): same as submission substance
- Molecular weight (if other than submission substance): same as submission substance
- Smiles notation (if other than submission substance): same as submission substance
- Structural formula attached as image file (if other than submission substance): see Fig.
- Substance type: organic
- Physical state: liquid
- Analytical purity: 90%
- Impurities (identity and concentrations):
- Purity test date: 09/09/99
- Lot/batch No.: 99350L08
- Expiration date of the lot/batch: 13/09/2000
- Stability under test conditions: stable
- Storage condition of test material: at room temeprature in the dark

Study design

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): Domestic activated sewage treatment plant RWZI Horstermeer (NL)
- Preparation of inoculum for exposure: the sludge was preconditioned to reduce the endogenous respiration rate by areating the sludge at 20 +/-1°C for 1 week.
- Concentration of sludge: 2 mg dry weight/l
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
8 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Composition of medium: As indicated by the OECD GL with one deviation: Amonium chloride was omitted from the medium to avoid nitrification.
- Additional substrate: sodium acetate
- Test temperature: 20 +/-1 °C
- pH: 7.4
- pH adjusted: no
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 280 ml BOD bottles
- Number of culture flasks/concentration: 2/timepoint
- Method used to create aerobic conditions: aerated medium
- Measuring equipment: oxygen meter WTW Oxi 96 with WTW EO96 electrode. pHmeter Metrohm 744

SAMPLING
- Sampling frequency: 1/week
- Sampling method: dedicated bottle/timepoint

CONTROL AND BLANK SYSTEM
- Inoculum blank: YES
- Abiotic sterile control: YES
- Toxicity control: YES
Reference substance
Reference substance:
acetic acid, sodium salt
Remarks:
6.6 mg/l

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Value:
3.3
Sampling time:
28 d
Details on results:
No toxicity to activated sludge was observed in samples containing sodium acetate and the test substance (no respiratory inhibition observed)

BOD5 / COD results

Results with reference substance:
72% biodegradation after 28 days

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
1,1,1,3,3-pentafluorobutane is not classified as readily degradable