Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Jan 4, 2008 to Feb 14, 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study performed using international guidelines and GLPs using the commercial product as test article and published in the literature

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
2008
Reference Type:
publication
Title:
Results of terrestrial and aquatic studies on the brominated flame retardant, decabromodiphenyl ethane, a.k.a. Ethane 1,2 bis(pentabromophenyl)
Author:
Hardy et al.
Year:
2009
Bibliographic source:
SETAC Annual Meeting, Nov 2009, New Orleans, LA

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
The test article was 97.64% DBDPEthane.

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
3 h
Post exposure observation period:
no

Test conditions

Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
NOEC
Effect conc.:
>= 10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
see below

Any other information on results incl. tables

Treatment

Respiration Rate (mg O2/L/h)

Inhibition (%)

Control

32.3, 31.3

---

DBDPEthane

(10mg/kg)

33.5

-5.3

Reference Inhibitor

(3, 15, 50 mg/kg)

32.4, 18.9, 6.1

-1.9, 40.6, 80.8

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
DBDPEthane did not adversely affect sludge respriation at a dose of 10 mg/L.

Executive summary:

The effect of DBDPEthane on activated sludge microorganisms maintained in an aerobic environment was assessed. The study contained control and reference groups and a treatment vessel. The control replicates were used to determine the background respiration rate of the sludge and were not dosed with the test or reference substance. The reference group was dosed with 3,5 -dichlorophenol, a known inhibitor of respiration, at concentrations of 3, 15 and 50 mg/L. The treatment vessel was dosed with DBDPEthane at a concentration of 10 mg/L. After an exposure period of 3 hr, the respiration rates of the test solutions were measured using a YSI Model 50 B Dissolved Oxyegen Meter. The respiration rates in the two controls were 32.3 and 31.3 mg O2/L/hr. The difference between the two control respriation rates was approximately 3% and was within the 15% difference limit established for the test. The validity of the test was further supporte by the results from the 3,5 -dichlorophenol reference group, which resulted in an EC50 of 19.4 mg/L with 95 % confidence limits of 3 and 50. The EC50 for the reference substance was within the 5 to 30 mg/L range considered acceptable for the test. The % respiration inhibition observed for DBDPEthane at 10 mg/L was -5.3%. Under the conditions of the study, DBDPEthane did not adversely affect sludge respriation.