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Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP, according to guideline, no deviations

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report date:
2002

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Reference substance name:
2,4-di-tert-butylphenyl diphenyl phosphite; 2-tert-butylphenyl diphenyl phosphite; 4-tert-butylphenyl diphenyl phosphite; triphenyl phosphite
EC Number:
941-802-9
Molecular formula:
Unspecified
IUPAC Name:
2,4-di-tert-butylphenyl diphenyl phosphite; 2-tert-butylphenyl diphenyl phosphite; 4-tert-butylphenyl diphenyl phosphite; triphenyl phosphite
Test material form:
other: yellowish liquid
Details on test material:
expiration date April 30, 2003

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
duplicate samples: 0, 48, 96 hours (except for loading rates of 46mg/L, 100 mg/L: sampling only before the strat of the test)
The two lowest test concentrations with loading rates of 4.6 and 10 mg/L were not analyzed, since they were below the 96-hour NOEC, determined in this test.

Test solutions

Vehicle:
no
Details on test solutions:
mixing 23, 50, 111, 232 and 499 mg test item into 5000 mL test water each. No auxiliary solvent or emulsifier was used. The test item was mixed into the test water as homogeneously as possible by ultrasonic treatment for 15 minutes and by intense stirring on a magnetic sfirrer at room temperature in the dark for 96 hours. A stirring period of 96 hours was chosen to dissolve a maximum concentration of the test item in test water.
These saturated aqueous dispersions were filtered through a membrane filter (Schleicher & Schuell, Type NC20, pore size 0.20 pm) just before the start of the test. The negative pressure of the filtration unit was reduced as far as possible not to suck the liquid test item through the filter and to avoid losses of volafile components of the test item during filtration.
The undiluted filtrates of the dispersions with dissolved test item were tested on fish as WAFs. Addifionally, a control was tested in parallel.
The test media were freshly prepared just before introduction of the fish. The actual concentrations of the test item in the test media were analytically determined.
The loading rates were based on the results of a range-finding test and on the results of a first main test.

Test organisms

Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)
Details on test organisms:
The study was performed with zebra fish (Brachydanio rerio). The test fish were obtained
from Zoohaus Schaub, CH-4410 Liestal, Switzeriand. In accordance with the test guidelines
the fish were held in the laboratories of RCC for at least three weeks without any medication.
Prior to the test start, they were acclimated for one week to the test water and temperature.
During holding and acclimatization unfil one day before the start of the test the fish were fed
with a commercial fish diet (TETRA MIN Hauptfutter, supplied by TETRA-Werke, D-49304
Melle, Germany). During holding and acclimatizafion no fish died in the test fish batch and all
fish were healthy.
From the acclimated test fish batch, 10 fish were measured at the start of the test: The mean
body length of the fish was 3.1 ± 0.15 cm (Mean ± SD), the mean body wet weight was
0.24 ± 0.04 g (Mean ± SD).

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h

Test conditions

Hardness:
2.5 mmol/L as CaCO3
Test temperature:
21-22°C
pH:
7.8-8
Dissolved oxygen:
>= 7.9 mg/L
Nominal and measured concentrations:
WAFs: 4.6, 10, 22, 46, 100 mg/L
Details on test conditions:
One glass aquarium with 4 liters test medium was used for each test concentration and the control. At the start of the test 7 fish were
introduced into each aquarium in a random order. The loading rate was 0.42 g fish wet weight per liter test medium. The test media and the control were slightly aerated during the test period. The fish were not fed during the test.

Reconstituted water: analytical grade salts were dissolved deionized water to obtain the following nominal concentrations:
in
CaCl2 X 2H2O 2.0 mmol/L (= 294 mg/L)
MgSO4 X 7H2O 0.5 mmol/L (=123 mg/L)
NaHCO3 0.75 mmol/L (= 65 mg/L)
KCl 0.075 mmol/L (= 5.8 mg/L)

Alkalinity 0.8 mmol/L
Ratio of Ca : Mg 4 : 1 (based on molarity)
Na:K 10 : 1 (based on molarity)


The test water was aerated prior to the preparation of the test media until oxygen saturation was reached.

Photoperiod of 16 hours light and 8 hours darkness (with a 30 minute transition period). Light intensity at light period approximately 190-500 Lux.

Results and discussion

Effect concentrationsopen allclose all
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
22 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality (fish)
Remarks on result:
other: WAF
Duration:
96 h
Dose descriptor:
LC0
Effect conc.:
22 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality (fish)
Remarks on result:
other: WAF
Duration:
96 h
Dose descriptor:
LOEC
Effect conc.:
46 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality (fish)
Remarks on result:
other: WAF
Duration:
96 h
Dose descriptor:
LC100
Effect conc.:
46 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality (fish)
Remarks on result:
other: WAF
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
32 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality (fish)
Remarks on result:
other: WAF
Details on results:
all test solutions were clear throughout the test
The LC50 and the 95% confidence interval at the observation dates could not be calculated by Probit Analysis or Moving Average Interpolation due to the steep concentration-effect relationship. Instead the LC50-values were determined as the geometric mean value of the two consecutive test concentrations with 0% and 100% mortality, and the 95% confidence intervals for the LC5O as the test concentrations with 0% and 100% mortality. The NOEC and the LCO were determined directly from the raw data. All calculations are based on the loading rates of the test item.

Applicant's summary and conclusion