Tall oil, maleated

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July-December 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: PARCOM part A,2005. Protocols on methods for the testing of chemicals used in offshore oil industry.

Version / remarks:

Method followed: Cefas SOP 2114 "A 10 day acute whole sediment bioassay using the anphipoid Corophium volutator"

Deviations:

yes

Remarks:

Five daviations from the study plan occurred . The deviations were determined not to have affected the validity of the study except deviation 4 which has been addressed.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Test item is insoluble in seawater and therefore a stock was prepared in 500 g of dry sediment using a solvent carrier (acetone).

Details on sediment and application:

Wet sediment was spiked with the EnvaMUl 600 stock, seawater was added at 2:1 sediment to seawater ratio and shaken on an orbital shaker for at least 3 hours at 150rpm. Control sediment was also prepared as wet sediment and seawater with no test item. Control and solvent controls were treated the same as the test concentrations. Approximately 300 g sediment slurry per replicate (3 reps per replicate) was poured into 1L glass beakers and left to settle overnight. The next day the beakers were topped up with seawater to 850 ml. The beakers were then left to settle for a further 6 hours before aeration was added. The beakers were left to aerate overnight. On day 0 the corophium volutator were seived out of the laboratory holding tank and kept in a glass tank with filtered seawater whillst being counted out. Corophium volutatur of a size greater than 5mm were selected and assigned randomly to samm beakers. When there were 20 in each beaker, it was topped up to 50 ml with seawater and the animals were gently added to the test beakers by tipping the beaker just under the water surface.

Test organisms (species):

Corophium volutator

Details on test organisms:

Individuals of a size greater than 5mm were used for the tst. The batch of Corophium used in the test was obtained from Green Blue Fish Ltd. and acclimated in the laboratory for 3 days before use.

Study type:

laboratory study

Test type:

static

Water media type:

other: seawater

Type of sediment:

not specified

Limit test:

no

Duration:

10 d

Exposure phase:

total exposure duration

Test temperature:

Range in the definitive study 13.0-14.7

pH:

Range in the definitive study 7.7-8.4

Dissolved oxygen:

Range in the definitive study : 41.1- 105.8 Di

Nominal and measured concentrations:

Nominal concentrations: 100, 220, 460, 1000, 2200, 4600, 10000 mg/L

Reference substance (positive control):

yes

Remarks:

ammonium chloride

Key result

Duration:

10 d

Dose descriptor:

EC50

Effect conc.:

1 548 mg/kg sediment dw

Nominal / measured:

estimated

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other:

Remarks:

The dissolved oxygen level in 2200 mg/kg replicate 2 was at 41.1 % which is below the limit of 85%. The low D.O could have caused this extra mortality; therefore, the data has been analysed with and without this replicate to see if it affected the final result. The median lethal concentration was 1548 mg/L when all replicates are included and 1631 mg/L when 2220 mg/kg replicate 2 is removed.

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

460 mg/kg sediment dw

Nominal / measured:

estimated

Conc. based on:

act. ingr.

Basis for effect:

mortality

Key result

Duration:

10 d

Dose descriptor:

LOEC

Effect conc.:

1 000 mg/kg sediment dw

Nominal / measured:

estimated

Conc. based on:

act. ingr.

Basis for effect:

mortality

Results with reference substance (positive control):

The reference test is different to the sediment assay. Ammonium chloride was used in water only (no sediment) exposure for 3 days at the following concentrations 36, 72, 110, 180 and 360 mg/L and 0 (control). There were 3 replicated of each and 300 mLs were dispensed into 500 mL glass beakers with very gentle aeration applied. After 72 h the number of Corophium volutator alive and dead was recorded. The EC50 of this test must be between 36 and 220 mg/L (nominals) for the definitive study to be valid.
The EC50 value for the reference test was 164.9 mg/L (confidence limits 148.6-183) The validity criteria are met.

Reported statistics and error estimates:

The data were analysed using Compehensive Environmental Toxicity information System (CETIS) statistical software (Tidepool scientific, V1.8.0.9)
The EC50 was calculated using Spearman-Karber. The NOEC and LOEC were calculated using Fishers exact test.

Validity criteria fulfilled:

yes

Conclusions:

A 10 day acute whole sediment bioassay assessment of EnvaMUl 600 was conducted using the amphipod Corophium volutator. The median lethal concentration (EC50) , the LOEC and NOEC were calculated and resulted to be:
EC50 10d: 1548 mg/L
LOEC: 1000 mg/L
NOEC: 460 mg/L

Executive summary:

A 10 day acute whole sediment bioassay assessment was conducted using the amphipod Corophium volutator in order to assess the toxicity of the test item EnvaMul 600.

A solubility study was conducted on EnvaMul 600. Test item resulted to be insoluble in seawater and therefore a stock was prepared in 500 g of dry sediment using a solvent carrier (acetone).

A range finding test and a definitive test were conducted. The definitive test concentrations were 0 (control), 100, 220, 460, 1000, 2200, 4600, 10000 mg/kg EnvaMul plus solvent control. There were 3 replicates per concentration.

The median lethal concentration (EC50) , the LOEC and NOEC were calculated and resulted to be:

EC50 10d: 1548 mg/L

LOEC: 1000 mg/L

NOEC: 460 mg/L

Description of key information

A 10 day acute whole sediment bioassay assessment of EnvaMUl 600 was conducted using the amphipod Corophium volutator. The median lethal concentration (EC50) , the LOEC and NOEC were calculated and resulted to be:

EC50 10d: 1548 mg/L

LOEC: 1000 mg/L

NOEC: 460 mg/L

Key value for chemical safety assessment

EC50 or LC50 for marine water sediment:

1 548 mg/kg sediment dw

EC10, LC10 or NOEC for marine water sediment:

460 mg/kg sediment dw