Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

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:
10 May - 07 Jun 2005
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)
Qualifier:
according to guideline
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
GLP compliance:
no
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): From aeration tank of a municipal waste water treatment plant (ARA Werdhölzli, Zürich), no adapted, not pre-conditioned.
- Pretreatment: Prior the test the sludge was washed twice with tap water.
- Concentration of sludge: 30 mg/L
Duration of test (contact time):
28 d
Initial conc.:
20.2 mg/L
Based on:
other: TOC
Remarks:
mean of two replicates
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: Aerobic mineral salts medium prepared with deionised water
- Test temperature: 22 +/- 0.5 °C
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes, Temperature-controlled dark room


TEST SYSTEM
- Culturing apparatus: 2500 mL closed glass bottles, containing a total volume of test solution of 2000 mL
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: aeration with CO2-free air, fitted to gas-absorption bottles (containing 125 mL of 0.15 M NaOH)
- Details of trap for CO2 and volatile organics if used: gas-absorption bottles filled with NaOH

SAMPLING
- Sampling frequency: daily

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 replicates
- Procedure control: 1 replicate
- Abiotic sterile control: no
- Toxicity control: no
Reference substance:
benzoic acid, sodium salt
Parameter:
% degradation (CO2 evolution)
Value:
94
Sampling time:
28 d
Details on results:
- lag phase: about 1 day
- pass level reached after about 7 days
Results with reference substance:
- Positive control (sodium benzoate): 98% degradation after 14 days

Table1: Valditiy criteria for OECD 301B

Criterion from the guideline

Outcome

Validity criterion fulfilled

Difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20%.

<5%

yes

Percentage degradation of the reference compound reached the pass level by day 14 (≥ 60%).

98% after 14 days.

yes

The toxicity control should degrade to at least 35% (based on DOC) or at least 25% (based on ThOD or ThCO2) within 14 d.

n.a.

n.a.

The IC content of the test substance suspension in the mineral medium at the beginning of the test must be less than 5% of the TC.

<5%

yes

The total CO2 evolution in the inoculum blank at the end of the test should not normally exceed 40 mg/L medium.

6.4 mg IC/L

yes

Validity criteria fulfilled:
yes
Remarks:
Please refer to table 1 at "Any other information on results incl. tables"
Interpretation of results:
readily biodegradable

Description of key information

Readily biodegradable: 94% in 28 days (OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

The ready biodegradability of Alcohols, C16-C18 (even numbered), ethoxylated, <2.5 EO was investigated in a non-GLP study according to OECD 301B. Domestic activated sludge was used as inoculum. The substance attained 94 % degradation based on CO2 evolution after 28 days of contact time.

Based on the results of the available study Alcohols, C16-C18 (even numbered), ethoxylated, <2.5 EO is assessed as readily biodegradable according to OECD criteria.