1,1-difluoroethane

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

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:

48 h

Dose descriptor:

LC50

Effect conc.:

364.06 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

not applicable

Conclusions:

The estimated 48-h LC50 for Daphnia is 364.060 mg/l (ECOSAR v1.1, neutral organics).

Executive summary:

The estimated 48 -h LC50 for Daphnia is 364.060 mg/l (ECOSAR v1.1, neutral organics).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

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:

48 h

Dose descriptor:

EC50

Effect conc.:

634.41 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on a read-across from an analogue from which EC50 = 980 mg/L

Validity criteria fulfilled:

yes

Conclusions:

Based on the read-across approach from the analogue 1,1,1,2-tetrafluoroethane, the 48h-EC50 of 1,1-difluoroethane was determined to be 634.41 mg/l based on mobility.

Executive summary:

An acute toxicity test with the analogue substance 1,1,1,2 -tetrafluoroethane on Daphnia magna was performed in accordance with the EU Method C.2 (Acute Toxicity for Daphnia). The test duration was 48 hours. The acute test with Daphnia magna showed a steep concentration-immobility curve. At mean measured concentrations of 870 and 1,100 mg/l the immobility after 48 h was 0 and 100%, respectively. The 48h-EC50 was determined to be 980 mg/l based on mobility. On the basis of these results, the read-across approach was applied and the 48h-EC50 based on mobility of 1,1 -difluoroethane was determined to be 634.41 mg/L.

Description of key information

Key study: Internationally accepted method, ECOSAR, EPA (USA). The estimated 48-h EC50 for aquatic invertebrates is 364.060 mg/l.

Supporting study: Secondary source. Test method according to EU Method C.2. GLP study. Based on the read-across approach from the analogue 1,1,1,2-tetrafluoroethane, the 48h-EC50 of 1,1-difluoroethane was determined to be 634.41 mg/l based on mobility.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

364.06 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

364.06 mg/L

Additional information

Key study: The estimated 48-h EC50 for aquatic invertebrates is 364.060 mg/l (ECOSAR v1.1, EPA, USA).

Supporting study: An acute toxicity test with the analogue substance 1,1,1,2 -tetrafluoroethane on Daphnia magna was performed in accordance with the EU Method C.2 (Acute Toxicity for Daphnia).The test duration was 48 hours.The acute test with Daphnia magna showed a steep concentration-immobility curve. At mean measured concentrations of 870 and 1,100 mg/l the immobility after 48 h was 0 and 100%, respectively. The 48h-EC50 was determined to be 980 mg/l based on mobility. On the basis of these results, the read-across approach was applied and the 48h-EC50 based on mobility of 1,1 -difluoroethane was determined to be 634.41 mg/l.