Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
other: Published report
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The data is available from a WHO study on the activity of linear alkaryl sulphonates. Although data may be based upon reliable data, this cannot be determined directly from the WHO report. The data has, however, been evaluated by the WHO expert committee and is therefore considered to be of good quality and sound reliability for WHO to have selected the data. It is therefore considered suitable for the purposes of hazard assessment when considered in conjunction with the partial degradation observed in the the ready biodegradation study.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1996

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
not specified
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sample is considered to be of the same chemical class as the registered substance

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Vehicle:
not specified

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
At 50 mg/litre, nitrification was decreased in extended aeration units that were treating synthetic sewage (Janicke & Niemitz, 1973). A bacterium similar to Klebsiella pneumoniae isolated from sewage degraded LAS at a concentration of 10 ml/litre, but a concentration of 20 ml/litre inhibited the growth of the bacterium by 39% (Hong et al., 1984).

Study design

Test type:
not specified
Water media type:
freshwater
Limit test:
yes
Post exposure observation period:
no data

Test conditions

Hardness:
no data
Test temperature:
no data
pH:
no data
Dissolved oxygen:
no data
Salinity:
no data
Reference substance (positive control):
not specified

Results and discussion

Effect concentrations
Duration:
8 h
Dose descriptor:
EC50
Effect conc.:
>= 3 200 - <= 5 000 mg/L
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
growth inhibition

Any other information on results incl. tables

The 8-h EC50, based on specific growth rate, of Pseudomonas fluorescensin solutions of C11.1LAS under static conditions was 3200-5600 mg/litre (Canton & Slooff, 1982).

There is evidence of partial biodegradation from the ready biodegradation data available that suggests the substance is not overtly toxic to sewage sludge microorganisms and it is therefore considered that the study is not scientifically justified.

Nevertheless, data is available from a WHO study on the activity of linear alkaryl sulphonates. Although data may be based upon reliable data, this cannot be determined directly from the WHO report. The data has, however, been evaluated by the WHO expert committee and is therefore considered to be of good quality and sound reliability for WHO to have selected the data. It is therefore considered suitable for the purposes of hazard assessment when considered in conjunction with the partial degradation observed in the the ready biodegradation study.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
Based on the evidence of partial degradation in the ready biodegradation study and data available from the WHO report ENVIRONMENTAL HEALTH CRITERIA 169 LINEAR ALKYLBENZENE SULFONATES AND RELATED COMPOUNDS the substance is considered to have a NOEC > 1000mg/l
Executive summary:

There is evidence of partial biodegradation from the ready biodegradation data available that might suggest the substance is not overtly toxic to sewage sludge microorganisms and it is therefore considered that the study is not scientifically justified.

Nevertheless, data is available from a WHO study on the activity of linear alkaryl sulphonates. Although data may be based upon reliable data, this cannot be determined directly from the WHO report. The data has, however, been evaluated by the WHO expert committee and is therefore considered to be of good quality and sound reliability for WHO to have selected the data. It is therefore considered suitable for the purposes of hazard assessment when considered in conjunction with the partial degradation observed in the the ready biodegradation study.

Based on the evidence of partial degradation in the ready biodegradation study and data available from the WHO report ENVIRONMENTAL HEALTH CRITERIA 169 LINEAR ALKYLBENZENE SULFONATES AND RELATED COMPOUNDS the substance is considered to have a NOEC > 1000mg/l