Bis(pentane-2,4-dionato-O,O')zinc

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Anderson BS, Hunt JW, Turpen SL, Coulon AR, Martin M, McKeown DL & Palmer FH (1990) Procedures manual for conducting toxicity tests developed by the Marine Bioassay Project. 90-10WQ. State Water Resources Control Board, Sacramento, CA, USA.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Zinc in filtered sea water from Granite Canyon, California, USA.

Test organisms (species):

other aquatic mollusc: Haliotis rufescens, Red Abalone, Haliotidae

Details on test organisms:

Origin of test organism: broodstock from Granite Canyon, California, USA; spawning induced in lab

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

10 d

Test temperature:

15°C

pH:

pH met acceptability criteria

Dissolved oxygen:

Salinity=ambient; met acceptability criteria

Nominal and measured concentrations:

Nominal concentrations, but chemically verified

Details on test conditions:

Filtered sea water from Granite Canyon, California, USA

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

10 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

zinc

Basis for effect:

other: development

Details on results:

Dose-response: EC50 reported
Analytically measured zinc concentrations were found to be close to nominal concentrations (coefficient of variation =17%).

NOEC≈ EC10 in 10-d continouos exposure;NOEC in 10 -d exposure recovery = 5.6 ug/L. However,10ug/L≈ EC10 in 48 -hr with and without 10-d exposure recovery.

Validity criteria fulfilled:

yes

Conclusions:

Study relevant for PNEC derivation. The 10d-NOEC Development is the most sensitive endpoint for this species.

Executive summary:

Experiments were conducted to compare a short-term 48-h aquatic toxicity test endpoint of abnormal larval shell development with other, more clearly adverse effects. In similar experiments conducted with zinc sulfate, red abalone (Haliotis rufescens) embryos were simultaneously exposed to identical dilution series and incubated for three different exposure periods: 48 h, 48 h followed by an 8-d recovery period in clean seawater, and 10 d of continuous exposure. Abnormal larval shell development was assessed in the 48-h short-term tests, and inhibition of metamorphosis was assessed in the exposure– recovery and continuous exposure experiments. For the zinc experiments, the median effective concentration (EC50) values for the 48-h exposure, the exposure–recovery experiment, and the continuous exposure experiment were 40, 34, and 32 mg/L zinc, respectively. Results indicate that toxicant concentrations causing abnormal larval shell development also inhibit metamorphosis and that larvae exposed to toxicant concentrations which inhibit larval shell development do not recover to metamorphose when transferred to clean seawater. None of the successfully metamorphosed postlarvae had deformed larval shells, indicating that shell deformity precludes survival past the planktonic stage. A longer (15-d) experiment allowed measurement of postlarval shell length in exposed postmetamorphic abalone. Insignificant differences in postlarval shell length indicated that the timing of larval metamorphosis was similar regardless of toxicant exposure and that the effects of the toxicant was to inhibit rather than to delay metamorphosis.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For long-time toxicity a dissociation of bis(pentane-2,4-dionato)zinc can be assumed.
By comparison of all ecotoxicity study resultes of bis(pentane-2,4-dionato)zinc to those of pentane-2,4-dione it can be assumed that the toxicity of the test material is determined only by the zinc moiety.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Anderson BS, Hunt JW, Turpen SL, Coulon AR, Martin M, McKeown DL & Palmer FH (1990) Procedures manual for conducting toxicity tests developed by the Marine Bioassay Project. 90-10WQ. State Water Resources Control Board, Sacramento, CA, USA.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Zinc in filtered sea water from Granite Canyon, California, USA.

Test organisms (species):

other aquatic mollusc: Haliotis rufescens, Red Abalone, Haliotidae

Details on test organisms:

Origin of test organism: broodstock from Granite Canyon, California, USA; spawning induced in lab

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

10 d

Test temperature:

15°C

pH:

pH met acceptability criteria

Dissolved oxygen:

Salinity=ambient; met acceptability criteria

Nominal and measured concentrations:

Nominal concentrations, but chemically verified

Details on test conditions:

Filtered sea water from Granite Canyon, California, USA

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

10 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

zinc

Basis for effect:

other: development

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

40 µg/L

Nominal / measured:

estimated

Conc. based on:

test mat. (total fraction)

Remarks:

recalculated for bis(pentane-2,4-dionato)zinc based on the value for dissolved zinc

Basis for effect:

other: development

Details on results:

Dose-response: EC50 reported
Analytically measured zinc concentrations were found to be close to nominal concentrations (coefficient of variation =17%).

NOEC≈ EC10 in 10-d continouos exposure;NOEC in 10 -d exposure recovery = 5.6 ug/L. However,10ug/L≈ EC10 in 48 -hr with and without 10-d exposure recovery.

Validity criteria fulfilled:

yes

Conclusions:

Study relevant for PNEC derivation. The 10d-NOEC Development is the most sensitive endpoint for this species.
The NOEC recalculated for bis(pentane-2,4-dionato)zinc is 263.6 g mol-1 / 65.4 g mol-1 x 10 µg/L = 40 µg/L
Endpoint (NOEC=40µg/L) was taken forward for PNEC derivation.

Executive summary:

Experiments were conducted to compare a short-term 48-h aquatic toxicity test endpoint of abnormal larval shell development with other, more clearly adverse effects. In similar experiments conducted with zinc sulfate, red abalone (Haliotis rufescens) embryos were simultaneously exposed to identical dilution series and incubated for three different exposure periods: 48 h, 48 h followed by an 8-d recovery period in clean seawater, and 10 d of continuous exposure. Abnormal larval shell development was assessed in the 48-h short-term tests, and inhibition of metamorphosis was assessed in the exposure– recovery and continuous exposure experiments. For the zinc experiments, the median effective concentration (EC50) values for the 48-h exposure, the exposure–recovery experiment, and the continuous exposure experiment were 40, 34, and 32 mg/L zinc, respectively. Results indicate that toxicant concentrations causing abnormal larval shell development also inhibit metamorphosis and that larvae exposed to toxicant concentrations which inhibit larval shell development do not recover to metamorphose when transferred to clean seawater. None of the successfully metamorphosed postlarvae had deformed larval shells, indicating that shell deformity precludes survival past the planktonic stage. A longer (15-d) experiment allowed measurement of postlarval shell length in exposed postmetamorphic abalone. Insignificant differences in postlarval shell length indicated that the timing of larval metamorphosis was similar regardless of toxicant exposure and that the effects of the toxicant was to inhibit rather than to delay metamorphosis.

Key value for chemical safety assessment

Marine water invertebrates

Marine water invertebrates

Effect concentration:

40 µg/L