Registration Dossier

Diss Factsheets

Administrative data

short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
03/09/04 - 28/10/05
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 203 (Fish, Acute Toxicity Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether
EC Number:
Cas Number:
Molecular formula:
1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether
Test material form:

Sampling and analysis

Analytical monitoring:
Details on sampling:
Sampling: Frequency –

First limit test: ca. 26 hours following the start of dosing, samples were taken from the 221 mg/l limit concentration to check the actual exposure concentration before the start of exposure. First and second limit test: at the start, after 48 hours and at the end of the 96-hour test period samples were taken from the blank-control and 221 mg/I.

Volume - 10ml from the approximate centre of the test vessel.

Storage - Samples taken after 48 and 96 hours of exposure were stored in a deep-freeze.

Test solutions

Details on test solutions:
Test solutions were derived from the test item, which was of 99.985% purity.

Test organisms

Test organisms (species):
Cyprinus carpio

Study design

Test type:
Water media type:
Limit test:
Total exposure duration:
96 h

Test conditions

Test temperature:
20 - 24°C
6 - 8.5
Dissolved oxygen:
Reference substance (positive control):

Results and discussion

Effect concentrations
Key result
96 h
Dose descriptor:
Effect conc.:
> 76 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Details on results:
No mortality was recorded in the range-finding test (which was a static method), and the recovery of the test item was low. Therefore for subsequent tests, a flow-through method was used to ensure that nominal concentrations were reached.

The 1st limit test reached concentrations of 73 mg/l, which is below the 20% threshold for limit tests (100 mg/l). No mortalities were observed during this study.

in the 2nd limit test, a mean of 76 mg/l was achieved across the 3 days of exposure, reaching as high as 85.6 mg/l. Precipitation was observed in the test environment. A total of 2 fish died during this test, which is below 50% of the median number of fish (total number of fish was 7)

Applicant's summary and conclusion

Validity criteria fulfilled:
Under the flow-through conditions of the present test 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether induced less than 50% mortality in carp at a mean measured test concentration of 76 mg/I, the highest exposure concentration that could be achieved and maintained stable in tap water.

Based on the observations of precipitate in the form of droplets in both limit tests, it cannot be excluded that fish were, at least occasionally, exposed to pure test substance.

In conclusion, the 96h-LC50 exceeded a mean measured concentration of 76 mg/I.
Executive summary:

The test substance 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether was evaluated for acute toxicity in fish in an OECD 203 study. Initially, a static test was proposed, however this was changed to a flow-through test following poor recovery of the test item from the testing environment.

During subsequent flow-through tests, it was still difficult to maintain nominal concentrations, and in the final study, a mean concentration of 76 mg/l was obtained. During this final test, 2 mortalities occurred, and it was noted that the fish seemed disorientated during the 96 hours.

As 50% mortality was not observed, the LC50 is considered to be >76 mg/l.