A mixture of: N-(4-chlorophenyl)-4-(2,5-dichloro-4-(dimethylsulfamoyl)phenylazo)-3-hydroxy-2-naphthalenecarboxamide; N-(4-chlorophenyl)-4-(2,5-dichloro-4-(methylsulfamoyl)phenylazo)-3-hydroxy-2-naphthalenecarboxamide

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study compliant to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OCDE n° 202 (1984) Directive CEE 84/449 (1984) - annexe V - méthode C2

GLP compliance:

yes

Test material

Test material information

Constituent 1

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: Dimethyl sulfoxyde 50 mg/l

Test organisms

Test organisms (species):

other aquatic crustacea: DM

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg CaCO3/L

Test temperature:

measurement of temperature was performed at the start of the study for each test media and for the control, then at the end of the study:
1) start: 19.4 - 20 °C
2) 48 h: 20.3 - 20.1 °C

pH:

measurement of pH was performed at the start of the study for each test media and for the control, then at the end of the study:
1) start: 7.88 - 7.93
2) 48 h: 7.7 - 7.79

Dissolved oxygen:

measurement of dissolved oxygen was performed at the start of the study for each test media and for the control, then at the end of the study:
1) start: 7.9 - 8.2 mg/L
2) 48 h: 7.8 - 8.1 mg/L

Nominal and measured concentrations:

To obtain 25 - 50 - 75 - 90 and 100% of test substance extract in test medium, and the single auxiliary substance concentration of 50 mg/L, appropriate volumes of extract were mixed into dilution water added with auxiliary substances, to give final volumes of 100 mL per concentration

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.1 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.1 mg/L

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 0.1 mg/L

Effect concentrations 4

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Details on results:

No immobilization of Daphnia was recorded during the 48 hour study period, until 100% of test substance extract, maximum possible concentration of exposure

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

EC(I)50 -48 hours for Daphnia: Higher than limit of solubility.

Executive summary:

The Daphnia (Daphnia magna) were exposed to a test substance extract for 48 hours.

The extract was prepared for the study by coarse filtration (paper filter) of a test substance saturated solution. This suspension, added with 50 mgll of Dimethyl sulfoxide, had been previously submitted to magnetic stirring for 4 hours. The study (range-finding study) was performed using 25 - 50 - 75 - 90 and 100% of test substance extract in test medium (20 Daphnia per group. A control group (not exposed to any substance) and an "auxiliary control" group (exposed only to the auxiliary substance at the same concentration as that

used for the test media) were also employed under the same experimental conditions.

As no immobilization was recorded during the 48-hour period, until 100% of test substance extract, the study was considered as completed and no EC (I) 50 - 48 hour evaluation could be performed.

The percentage of immobilization was noted approximately 24 and 48 hours after the start of the study. Measurements of pH, dissolved oxygen and temperature were performed at the start of the study for each test medium and for the control, then at the end of the study.

The study concentrations were expressed as percent of the test substance extract in test medium (volume by volume). Each test medium was twice sampled (at the beginning and at the end of the study).

The quality criteria for the study as notified in the O.E.C.D. and E.E.C. protocols relative to the dissolved oxygen concentration, the degree of immobiliz.ation of Daphnia in the control media and their absence from the surface, were respected.