Dibutyl hydrogen phosphate

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sediment simulation testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Cross-reference

Reason / purpose for cross-reference:

reference to other assay used for intermediate effect derivation

Reference

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05-06/1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.9 (Biodegradation: Zahn-Wellens Test)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Principles of method if other than guideline:

Cited as Directive 87/302/EEC and DIN 38 412 part 25

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, industrial, adapted

Details on inoculum:

- Activated sludge of aeration tanks of a sewage treatment plant treating predominantly sewage of industrial origin (STP Leverkusen Bürrig)
- Date of collections : 1991-05-22
- Concentration of inoculum (dry weight) : 1000 mg/L

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

DOC

Details on study design:

The substance is dissolved in a mineral medium, inoculated with a mixed population of aquatic microorganisms and 28 days under aerobic conditions were incubated in the dark at 20 – 25°C. The biodegradation of the substance is determined during this time by the decrease of the DOC.

Parameter:

% degradation (DOC removal)

Value:

9

Sampling time:

7 d

Parameter:

% degradation (DOC removal)

Value:

97

Sampling time:

14 d

Parameter:

% degradation (DOC removal)

Value:

> 98

Sampling time:

21 d

Key result

Parameter:

% degradation (DOC removal)

Value:

> 98

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

Within 28 days a degradation of > 98 % was determined according to the EU Method C.9 (Biodegradation: Zahn-Wellens Test). Therefore dibutyl hydrogen phosphate is considered to be "Inherently Biodegradable".

Executive summary:

Dibutyl hydrogen phosphate is dissolved in a mineral medium, inoculated with a mixed population of aquatic microorganisms and 28 days under aerobic conditions were incubated in the dark at 20–25°C. The biodegradation of dibutyl hydrogen phosphate is determined using the removal of the DOC. Within 28 days a degradation of > 98 % was determined according to the EU Method C.9 (Biodegradation: Zahn-Wellens Test). Therefore dibutyl hydrogen phosphate is considered to be "Inherently Biodegradable".

Results and discussion

Transformation products:

no