1,1-difluoroethane

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Remarks:

Internationally accepted method, ECOSAR, EPA (USA)

Justification for type of information:

See attached (Q)SAR prediction reporting format (QPRF).

Principles of method if other than guideline:

QSAR calculation by ECOSAR v1.1, EPA, USA (attached QSAR Prediction Reporting Format, QPRF).

GLP compliance:

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

719.611 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Validity criteria fulfilled:

not applicable

Conclusions:

The estimated 96-h LC50 for fish is 719.611 mg/l (ECOSAR v1.1, neutral organics).

Executive summary:

The estimated 96-h LC50 for fish is 719.611 mg/l (ECOSAR v1.1, neutral organics).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Read-across from an analogue substance for which a guideline study is available (Klimish score=4 because secondary source)

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
See attached reporting format.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

291.31 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Based on a read-across from an analogue for which LC50 = 450 mg/l

Validity criteria fulfilled:

not applicable

Conclusions:

Based on the read-across approach from the analogue 1,1,1,2-tetrafluoroethane, the 96h-LC50 of 1,1-difluoroethane was determined to be 291.21 mg/l.

Executive summary:

An acute toxicity test with the analogue substance 1,1,1,2 -tetrafluoroethane on Rainbow trout (Oncorhynchus mykiss) was performed in accordance with the EU Method C.1 (Acute Toxicity for Fish). Fish were exposed for 96 hours to the test substance. Analytical monitoring was performed during test performance. No mortality was found after 96 h of exposure at mean measured concentrations of 180 and 300 mg/l, but symptoms of toxicity were observed at these concentrations (dark discoloration, quiescence, and sounding behaviour). No symptoms of toxicity occurred at a mean measured concentration of 87 mg/l. The 96h-LC50 (based on mortality) was determined to be 450 mg/l. Based on these results, the read-across approach was applied and the 96h-LC50 of 1,1 -difluoroethane in Rainbow trout was determined to be 291.31 mg/l.

Description of key information

Key study: Internationally accepted method, ECOSAR, EPA (USA). The estimated 96-h LC50 for fish is 719.611 mg/l.

Supporting study: Secondary source. Test method according to EU Method C.1. GLP study. Based on the read-across approach from the analogue 1,1,1,2-tetrafluoroethane, the 96h-LC50 of 1,1-difluoroethane for freshwater fish was determined to be 291.21 mg/l.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

719.611 mg/L

Marine water fish

Marine water fish

Effect concentration:

719.611 mg/L

Additional information

Key study: The estimated 96 -h LC50 for fish is 719.611 mg/l (ECOSAR v1.1, EPA, USA).

Supporting study: An acute toxicity test with the analogue substance 1,1,1,2 -tetrafluoroethane on Rainbow trout (Oncorhynchus mykiss) was performed in accordance with the EU Method C.1 (Acute Toxicity for Fish). Fish were exposed for 96 hours to the test substance. Analytical monitoring was performed during test performance. No mortality was found after 96 h of exposure at mean measured concentrations of 180 and 300 mg/l, but symptoms of toxicity were observed at these concentrations (dark discoloration, quiescence, and sounding behaviour). No symptoms of toxicity occurred at a mean measured concentration of 87 mg/l. The 96h-LC50 (based on mortality) was determined to be 450 mg/l. Based on these results, the read-across approach was applied and the 96h-LC50 of 1,1 -difluoroethane in Rainbow trout was determined to be 291.31 mg/l.