Hydrocarbons, C18-C22, n-alkanes, n-alkenes

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: short-term

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

10 d

Dose descriptor:

LC50

Effect conc.:

2 026 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence limits: 1212 - 3035 mg/kg dry sediment

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

687 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

10 d

Dose descriptor:

LOEC

Effect conc.:

2 196 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

Abnormal behaviour among the Corophium was recorded on day 3 at 95, 977, 3125 and 10000 mg/kg, on day 6 at 977, 3125 and 10000 mg/kg and on day 10 at 977 and 3125 mg/kg.

Reported statistics and error estimates:

The LC50 value was calculated by Maximum Likelihood-Weibull (P=0.25) and the NOEC and LOEC values by Fisher's Exact Test using ToxCalc v5.0.

Table: Mortality after 10 -days exposure

Nominal concentration (mg/kg)		Number alive*		Total number dead	Mortality
Wet sediment	Dry sediment	Replicate 1	Replicate 2		(%)
0 (control)	0 (control)	10	10	0	0
95	215	6	10	4	20
305	687	9	8	3	15
977	2196	6	5	9	45
3125	7021	1	1	18	90
10000	22470	0	0	20	100

* Number exposed in each replicate = 10

Validity criteria fulfilled:

yes

Conclusions:

The 10-day LC50 of the test item to Corophium volutator was determined to be 2026 mg/kg dry sediment (95% confidence limits 1212 - 3035). The highest no-observed effect concentration (NOEC) after 10-days exosure was 687 mg/kg dry sediment. Abnormal behaviour among the Corophium was recorded on day 3 at 95, 977, 3125 and 10000 mg/kg, on day 6 at 977, 3125 and 10000 mg/kg and on day 10 at 977 and 3125 mg/kg. The water quality measurements of the test solutions were within the ranges specified in the test guideline and this was acceptable. None of the twenty control corophium died during the study and this represents an acceptable level of health of the test organisms maintained under test conditions.

Executive summary:

The study was performed to investigate the toxicity of the test item to Corophium volutator. The objective of this study was to determine the 10 -day LC50 after a 10 -day exposure period. The toxicity test was carried out according to the testing laboratory SOPs, based on the guidelines produced by the OSPAR/PARCOM Protocols on Methods for the Testing of Chemicals Used in the Offshore Industry 2006 Part A: A sediment bioassay using an amphipod Corophium sp. The study was performed in compliance with GLP. The 10-day LC50 of the test item to Corophium volutator was determined to be 2026 mg/kg dry sediment (95% confidence limits 1212 - 3035). The highest no-observed effect concentration (NOEC) after 10-days exosure was 687 mg/kg dry sediment. Abnormal behaviour among the Corophium was recorded on day 3 at 95, 977, 3125 and 10000 mg/kg, on day 6 at 977, 3125 and 10000 mg/kg and on day 10 at 977 and 3125 mg/kg. The water quality measurements of the test solutions were within the ranges specified in the test guideline and this was acceptable. None of the twenty control corophium died during the study and this represents an acceptable level of health of the test organisms maintained under test conditions.

Description of key information

The 10-day LC50 under static conditions was determined in compliance with GLP according to OSPAR/PARCOM 2006 Protocol. The mud shrimp corophium volutator was exposed to 5 different test item concentrations ranging from 95 to 10000 mg/kg dry sediment. 20 individuals each concentration plus 20 individuals untreated as a control were exposed for 10 days in natural sediment overlayed by artificial saltwater. Records were made of the number of observed alive as well as any showing abnormal behaviour on days 3, 6 and 10. The 10-day LC50 of the test item to Corophium volutator was determined to be 2026 mg/kg dry sediment (95% confidence limits 1212 - 3035). The highest no-observed effect concentration (NOEC) after 10-days exposure was 687 mg/kg dry sediment.

Key value for chemical safety assessment

EC50 or LC50 for marine water sediment:

2 026 mg/kg sediment dw

EC10, LC10 or NOEC for marine water sediment:

687 mg/kg sediment dw