Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Not a standard stuyd, no LC50 is calculated, the exposure duration is too short (4 h max) and effects are observed 1 to 3 weeks after exposure. This species is filamentous.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Effect of Alkylating Agents on Cladophora crispata (Roth.) Kuetz.
Author:
Aruna M , Vidyavati
Year:
2008
Bibliographic source:
vegetos 21(1): 105-119

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Exposure for 1 to 4 hours. Observations 1 to 3 weeks after exposure. Determination of survival, dry weight, chlorophyll content.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
no data

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
other: Cladophora crispata

Study design

Test type:
not specified
Water media type:
freshwater
Limit test:
no
Total exposure duration:
4 h

Results and discussion

Effect concentrations
Remarks on result:
other: no calculation performed

Any other information on results incl. tables

The percentage of healthy cells was lower compared to control in all the DES treated cultures which progressively increased by second week in 0.0001%. But, 0.01% concentration treated cultures showed decrease in their survival. In samples treated with higher concentration (0.1%) and longer duration (4 hours) the filaments of the alga could not survive up to third week and the cells were unhealthy and showed brown chloroplast. The percentage of damaged cells increased with increasing concentrations and durations of the diethyl sulphate treatment. The dry weight values increased gradually from first to third week in the control samples. There was a dose-dependent decrease of the dry weight and chlorophyll content in DES exposed cells. 0.01%, and 0.1% concentrations treated for 4 hours duration, the cultures showed completely decreased values in the chlorophyll content.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
Effects of DES were observed on this alga but no LC50 or NOEC is available.
Executive summary:

The algal material selected for the test was Cladophora crispata (Roth) Kuetz. Diethyl sulphate was tested in various percentage concentrations (0.0001, 0.001, 0.01 and 0.1) for duration of 1, 2 and 4 hours for a period of three weeks. Observations were recorded with reference to survival percentage, dry weight, chlorophyll content, morphological and cytological variations.

Effects of DES were observed on this alga but no LC50 or NOEC is available.