Alkanes, C16-47, branched and linear

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

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

Lipid content:

7.3 - 8.4 %

Time point:

start of exposure

Lipid content:

3.9 - 5 %

Time point:

end of exposure

Key result

Type:

BCF

Value:

<= 6 dimensionless

Basis:

whole body d.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.5 mg/l (hign concentration level)

Key result

Type:

BCF

Value:

<= 29 dimensionless

Basis:

whole body d.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.05 mg/l (low concentration level)

Results with reference substance (positive control):

No positive control.

Details on results:

Monitoring of Test Conditions:
During the test period, the dissolved oxygen in all water chambers was kept at > 60 % (7.2-8.4 mg/L) of the saturated oxygen concentration and the water temperature was kept at 24°C ± 2°C (23.9-24.4°C), both of which satisfied the test conditions. The pH value was kept at 7.3-7.6, which was within the proper range for fish rearing (6.0-8.5).

During the test period, there was no abnormality in shape of the body or in swimming and eating behaviour in the fish at all concentration levels throughout the test period. Therefore, it was confirmed that the test fish had been reared appropriately.

Lipid content:
7.9% (n=3, 7.3 - 8.4%) at the start of the exposure period
4.3% (n=3, 3.9-5.0%) at the end of the exposure period
The Standard Operation Procedure of the laboratory establishes the criteria of lipid content as below.
- The average of lipid content falls within 3.0% to 6.0%.
- The variation of lipid content at the end against at the start falls within ±25%.
The average oflipid content at the start was 7.9% and exceeded the criterion. With the high average of start lipid content, the variation of lipid content was 54% and also exceeded the criterion. The feeding through the acclimation and the exposure period was performed properly. Therefore, the reason for the high lipid content at the start was unexplained.

Concentration of Test Substance in Test Water:
The mean concentration of the test substance during the exposure period was 0.432 mg/L at the high concentration level, and 0.0436 mg/L at the low concentration level, both of which were > 80% of the nominal concentrations. The variations of the test substance concentrations in the test waters at both concentration levels were kept within ±20% of the mean measured values.

BCF of Test Substance in Test Fish:
The bioconcentration factor (BCF) during the exposure period was <2 to 6 at the high concentration level, and <11 to 29 at the low concentration level.

At both of the high concentration level and low concentration level, the variations of mean BCF at the three consecutive measurements were not confirmed to fall within ±20%. However, all of the BCF values during the exsposure period were less than 100, thus the BCF were considered to reach the steady-state. The bioconcentration factor at the steadystate (BCFss) was ≤6 at the high concentration level, and ≤29 at the low concentration level.

Please see attached background material for result tables.

Based on the results, the bioaccumulation potential of the test substance in fish tissues is judged to be low.

Validity criteria fulfilled:

yes

Remarks:

All results satisfied the validity criteria specified for this study.

Conclusions:

The bioconcentration factor at the steadystate (BCFss) was ≤6 at the high concentration level, and ≤29 at the low concentration level.

Based on the results, the bioaccumulation potential of the test substance in fish tissues is judged to be low.

Executive summary:

Methods:

The study was conducted in accordance with the Test Method Relating to New Chemical Substances <Bioconcentration test of chemical substances in fish and shellfish> (Yakushokuhatsu No.1121002, Heisei 15.11.13 Seikyoku No.2, Kanpokihatsu No.031121002, November 21, 2003; the latest revision, November 20, 2006), which prescribes the procedure for testing new chemical substances as required by the Chemical Substances Control Law of Japan.

Test substance in test water (nominal concentrations)

High concentration level: 0.5 mg/L

Low concentration level: 0.05 mg/L

Control: 0 mg/L

Vehicles in test water

High concentration level: Tween-80 10 mg/l, Tetrahydrofuran 15 ppm (v/v)

Low concentration level: Tween-80 1 mg/l, Tetrahydrofuran 24 ppm (v/v)

Control: Tween-80 10 mg/l, Tetrahydrofuran 15 ppm (v/v)

Supply of test water: Continuous flow-through dilution system (800 L/day)

Exposure period: 29 days.

The last sampling date was day 28. On day 29, the bioconcentration factors were confirmed to have reached the steady-state, which enable exposure to be completed.

Analytical Method:

After pretreatment, the test substacne was determined by gas chromatography mass spectrometer (GC/MS)

Lipid content in test fish:

7.9% (n=3, 7.3 -8.4%) at the start of the exposure period

4.3% (n=3, 3.9 -5.0%) at the end of the exposure period

96 -hour LC50 to Medaka: >50 mg/l

Results:

The bioconcentration factors (BCF) obtained in this study were as follows:

Exposure period		8	12	15	21	28
High concentration level
Mean conc. In test water (mg/l)		0.433	0.448	0.436	0.434	0.432
	Group 1	<2	1	1	<2	<2
	Group 2	6	2	<2	<2	<2
Low concentration level
Mean conc. In test water (mg/l)		0.0462	0.0452	0.0442	0.0431	0.0436
	Group 1	<11	11	<11	12	<11
	Group 2	<11	<11	16	13	29

 

BCFss: The steady-state bioconcentration factor

 

High concentration level BCFss: ≤6

Low concentration level BCFss: ≤29

At both of the high concentration level and low concentration level, the variations of mean BCF at the three consecutive measurements were not confirmed to fall within ±20%. However, all of the BCF values during the exsposure period were less than 100, thus the BCF were considered to reach the steady-state. The bioconcentration factor at the steadystate (BCFss) was ≤6

at the high concentration level, and ≤29 at the low concentration.

Based on the results, the bioaccumulation potential of the test substance in fish tissues is judged to be low.

Description of key information

bioconcentration factor at the steadystate (BCFss): 
- ≤6 at the high concentration level (0.5 mg/L nominal)
- ≤29 at the low concentration level (0.05 mg/L nominal).

Additional information

The determination on the read across substance (C18 -C50 branched, cyclic and linear hydrocarbons - Distillates) was carried out using a Test Method Relating to New Chemical Substances <Bioconcentration test of chemical substances in fish and shellfish>, which prescribes the procedure for testing new chemical substances as required by the Chemical Substance Control Law of Japan.

The bioconcentration factor at the steadystate (BCFss) was ≤6 at the high concentration level (0.5 mg/L nominal), and ≤29 at the low concentration level (0.05 mg/L nominal).

Based on the results, the bioaccumulation potential of the test substance in fish tissues is judged to be low.