Hydrocarbons, C11-C13 (odd numbered), n-alkanes, <2% aromatics

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

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

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 (Bioconcentration: Flow-through Fish Test)

Deviations:

no

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility: 1 µg/L (Tolls et al. 2002. J Phys Chem A 106: 2760-2765)
- log Pow: 7.0 (Tolls et al. 1999. Physico-chemical properties and bioconcentration studies on alkanes. Utrecht, RITOX)

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: Fish samples were netted out of the exposure tank after 2, 4, 8, 10, 11, and 13 days.
- Sample storage conditions before analysis: Fish were killed by immersion in liquid nitrogen and stored at -25 °C until analysis. All analyses were performed within two weeks after sampling.
- Details on sampling and analysis of test organisms and test media samples: A 200 µL test sample was withdrawn from the exposure vessel and injected into pre-crimped vials using a gas-tight syringe. Vortexing of the sample for 30 s appeared to be sufficient to accelerate evaporation of the alkanes from the water phase into the headspace.

Vehicle:

no

Details on preparation of test solutions, spiked fish food or sediment:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: To generate adequate volumes of test solution with a constant concentration of test substance, two series, each containing four 10 L flasks were setup in parallel. Distilled water and hydrocarbon were added to the saturated solution generation part of the system and allowed to equilibrate with each other for eight days. The exposure solution was prepared by mixing the effluent from the two series with an equal volume of distilled water and a small volume of a concentrated electrolyte solution in a cylinder. In this manner, the saturated solutions were diluted by a factor of 2 to decrease the chance that any hydrocarbon in non-dissolved form would enter the aquarium.

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow
- Source: reared in the hatchery of the Utrecht University
- Age at study initiation: 6-9 months
- Weight at study initiation (mean and range, SD): 0.5 - 1.1 g
- lipid content: usually 3-4%
- Feeding during test: no

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

13 d

Hardness:

not specified

Test temperature:

22 °C

pH:

not specified

Dissolved oxygen:

not specified

Details on test conditions:

TEST SYSTEM
- Test vessel: 5L Erlenmeyer flaks fitted with a septum-sealed sampling port and an outlet for the exposure water.
- Type: closed
- Aeration: The oxygen concentration in the fish aquarium was maintained by slowly purging the exposure solution with air that had been saturated with liquid hydrocarbon coated as a thin film on glass wool (preconditioning the air with the test compound minimises evaporation).
- Type of flow-through: Then, the experiment was started and distilled water was pumped into the first vessel, thereby establishing a hydraulic gradient-dependent flux of water from one vessel to the next along each series. With a pumping rate of 4 L/d and a volume of 40 L in each series, the retention time during the experiment was 10 days.
- Renewal rate of test solution (frequency/flow rate): The final water flow rate into the exposure aquarium was 16 L per day. Given the mass of fish in the aquarium (ca. 12 g), this resulted in specific flow rates of ca. 1.3 L/g/day.
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 4
- No. of vessels per control / vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: concentrated electrolyte solution. It consisted of CaCO3 (0.75 mM), NaHCO3 (1.51 mM), NaNO3 (1.01 mM), MgSO4 (0.46 mM), KH2PO4 (0.04 mM), Na2SiO3 (0.1 mM).

Nominal and measured concentrations:

Measured (median): 0.25 µg/L
Measured (mean): 0.42 ± 0.42 µg/L

Reference substance (positive control):

no

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: estimated as LOQ/Cw

Type:

BCF

Value:

240 L/kg

Basis:

other: estimated as LOQ/Cw

Time of plateau:

13 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.25 µg/L

Test substance concentrations in water

The average water concentration of n-dodecane was 0.42 (± 0.42) µg/L. The presence of strongly deviating values can be inferred from the large standard deviations, which shows the time course of the average daily concentration of n-dodecane in the exposure aquarium. It should be noted that 80% of the measured concentration data fall within the range of 0.1–0.6 µg/L. The proximity of these concentrations to the method limit of quantification (0.05 µg/L) explains one part of the variability, however the large error bars are usually the result of measuring one aberrantly high concentration in a series of replicates. We speculate that these outliers are due to excessive absorption of n-dodecane from the sampling port septum into the SPME fibre during sampling the water. Therefore, the outlying values are not assumed to reflect the n-dodecane concentration in the water. Taking this into account we consider the median concentration of 0.25 µg/L to be a representative measure for the actual exposure of the fish during the experiment.

Test substance concentrations in fish

The GC peak of n-dodecane eluted in a region of the chromatogram including many peaks from substances arising from the digestion of the fish tissues. Therefore, the limit of quantitation of n-dodecane was rather high in fish samples and was estimated to be 60 µg/kg. In the chromatograms of the fish exposed in the bioconcentration experiment, n-dodecane could not be quantified since the n-dodecane peak was never three times above the ‘‘noise level’’ in fish samples. Hence, quantification of n-dodecane bioconcentration could not go farther than specifying an upper limit (BCFmax) that was not exceeded in the present study.

Validity criteria fulfilled:

not specified

Executive summary:

The bioconcentration potential of n-dodecane was investigated in a study according to OECD guideline 305 using Pimephales promelas as test organism. The median concentration of the test substance in the test water was measured to be 0.25 µg/L. The concentration of the test substance in fish did not exceed the method limit of detection of 60 µg/kg. Thus, the upper limit of the BCF is estimated by dividing the method LOD by the exposure concentration and a BCF value of 240 L/kg is derived. The measured BCF is small compared to the hydrophobicity of the test substance. Given, that linear hydrocarbons are known to be biotransformed by fish, it appears that efficient metabolism prevents bioaccumulation in fish.

Reference 2

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Validated QSAR model. Calculation for component of Reaction mass of Hydrocarbons, C11-C13 (odd numbered), n-alkanes

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Test organisms (species):

other: fish

Route of exposure:

aqueous

Test type:

other: calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: BCFBAF v3.01
- Result based on calculated log Pow of: 5.74 (KOWWIN v1.68)

Type:

BCF

Value:

121 L/kg

Basis:

whole body w.w.

Remarks on result:

other: The substance is within the applicability domain of the BCFBAF submodel: Bioconcentration factor (BCF; Meylan et al., 1997/1999).

Type:

BCF

Value:

1 420 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: Upper trophic, incl. biotransformation estimates; The substance is within the applicability domain of the BCFBAF submodel: Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003).

Type:

BAF

Value:

2 014 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: Upper trophic, incl. biotransformation estimates; The substance is within the applicability domain of the BCFBAF submodel: Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003).

Details on kinetic parameters:

Biotransformation half-life (days): 4.013
Biotransformation rate (kM, normalised to 10 g fish at 15 °C): -
The substance is within the applicability domain of the BCFBAF submodel: Biotransformation rate in fish (kM; Arnot et al., 2008a/b).

Summary Results:

Log BCF (regression-based estimate): 2.08 (BCF = 121 L/kg wet-wt)

Biotransformation Half-Life (days) : 4.01 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 3.30 (BAF = 2.01e+003 L/kg wet-wt)

 

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 5.74

 

Equation Used to Make BCF estimate:

Log BCF = 0.6598 log Kow - 0.333 + Correction

 

Correction(s):                   Value

Alkyl chains (8+ -CH2- groups) -1.374

 

Estimated Log BCF = 2.082 (BCF = 120.9 L/kg wet-wt)

 

Whole Body Primary Biotransformation Rate Estimate for Fish:

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag |  2 | Linear C4 terminal chain [CCC-CH3]       | 0.0341 | 0.0682

Frag |  2 | Methyl [-CH3]                            | 0.2451 | 0.4902

Frag |  9 | -CH2- [linear]                         | 0.0242 | 0.2177

Frag |  1 | N-Alkane (linear) ... < C22               | 0.0000 | 0.0000

L Kow|  * | Log Kow =  5.74 (KowWin estimate)        | 0.3073 | 1.7652

MolWt|  * | Molecular Weight Parameter                |         | -0.4008

Const|  * | Equation Constant                         |    | -1.5058

RESULT  |       LOG Bio Half-Life (days)            |         | 0.6035

RESULT  |           Bio Half-Life (days)            |         |  4.013

NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |

Biotransformation Rate Constant:

kM (Rate Constant): 0.1727 /day (10 gram fish)

kM (Rate Constant): 0.09713 /day (100 gram fish)

kM (Rate Constant): 0.05462 /day (1 kg fish)

kM (Rate Constant): 0.03072 /day (10 kg fish)

 

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

Estimated Log BCF (upper trophic) = 3.152 (BCF = 1420 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 3.304 (BAF = 2014 L/kg wet-wt)

Estimated Log BCF (mid trophic)  = 3.281 (BCF = 1908 L/kg wet-wt)

Estimated Log BAF (mid trophic)  = 3.659 (BAF = 4559 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 3.318 (BCF = 2078 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 3.923 (BAF = 8369 L/kg wet-wt)

 

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

Estimated Log BCF (upper trophic) = 4.276 (BCF = 1.888e+004 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 6.124 (BAF = 1.33e+006 L/kg wet-wt)

Executive summary:

QPRF: BCFBAF v3.01

 

1.	Substance	See “Test material identity”
2.	General information
2.1	Date of QPRF	See “Data Source (Reference)”
2.2	QPRF author and contact details	See “Data Source (Reference)”
3.	Prediction
3.1	Endpoint (OECD Principle 1)	Endpoint	Bioaccumulation (aquatic)
		Dependent variable	- Bioconcentration factor (BCF) - Bioaccumulation factor (BAF; 15 °C) - Biotransformation rate (kM) and half-life
3.2	Algorithm (OECD Principle 2)	Model or submodel name	BCFBAF Submodels: 1) Bioconcentration factor (BCF; Meylan et al., 1997/1999) 2) Biotransformation rate in fish (kM; Arnot et al., 2008a/b) 3) Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003)
		Model version	v. 3.01
		Reference to QMRF	Estimation of Bioconcentration, bioaccumulation and biotransformation in fish using BCFBAF v3.01 (EPI Suite v4.11)
		Predicted value (model result)	See “Results and discussion”
		Input for prediction	Chemical structure via CAS number or SMILES; log Kow (optional)
		Descriptor values	- SMILES: structure of the compound as SMILES notation - log Kow - Molecular weight
3.3	Applicability domain (OECD principle 3)	Domains:
		1) Bioconcentration factor (BCF; Meylan et al., 1997/1999)
		a) Ionic/non-Ionic	The substance is non-ionic.
		b) Molecular weight (range of test data set): - Ionic: 68.08 to 991.80 - Non-ionic: 68.08 to 959.17 (On-Line BCFBAF Help File, Ch. 7.1.3 Estimation Domain and Appendix G)	The substance is within range (156.31 g/mol).
		c) log Kow (range of test data set): - Ionic: -6.50 to 11.26 - Non-ionic: -1.37 to 11.26 (On-Line BCFBAF Help File, Ch. 7.1.3 Estimation Domain and Appendix G)	The substance is within range (5.74).
		d) Maximum number of instances of correction factor in any of the training set compounds (On-Line BCFBAF Help File, Appendix E)	Not exceeded.
		2) Biotransformation rate in fish (kM; Arnot et al., 2008a/b)
		a) The substance does not appreciably ionize at physiological pH. (On-Line BCFBAF Help File, Ch. 7.2.3)	fulfilled
		b) Molecular weight (range of test data set): 68.08 to 959.17 (On-Line BCFBAF Help File, Ch. 7.2.3)	The substance is within range (156.31 g/mol).
		c) The molecular weight is ≤ 600 g/mol. (On-Line BCFBAF Help File, Ch. 7.2.3)	fulfilled
		d) Log Kow: 0.31 to 8.70 (On-Line BCFBAF Help File, Ch. 7.2.3)	The substance is not within range (5.74).
		e) The substance is no metal or organometal, pigment or dye, or a perfluorinated substance. (On-Line BCFBAF Help File, Ch. 7.2.3)	fulfilled
		f) Maximum number of instances of biotransformation fragments in any of the training set compounds (On-Line BCFBAF Help File, Appendix F)	Not exceeded.
		3) Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003)
		a) Log Kow ≤ 9 (On-Line BCFBAF Help File, Ch. 7.3.1)	fulfilled
		b) The substance does not appreciably ionize. (On-Line BCFBAF Help File, Ch. 7.3.1)	fulfilled
		c) The substance is no pigment, dye, or perfluorinated substance. (On-Line BCFBAF Help File, Ch. 7.3.1)	fulfilled
3.4	The uncertainty of the prediction (OECD principle 4)	1. Bioconcentration factor (BCF; Meylan et al., 1997/1999) Statistical accuracy of the training data set (non-ionic plus ionic data): - Correlation coefficient (r^2) = 0.833 - Standard deviation = 0.502 log units - Absolute mean error = 0.382 log units   2. Biotransformation Rate in Fish (kM) Statistical accuracy (training set): - Correlation coefficient (r^2) = 0.821 - Correlation coefficient (Q^2) = 0.753 - Standard deviation = 0.494 log units - Absolute mean error = 0.383 log units   3. Arnot-Gobas BAF/BCF model No information on the statistical accuracy given in the documentation.
3.5	The chemical mechanisms according to the model underpinning the predicted result (OECD principle 5)	1. The BCF model is mainly based on the relationship between bioconcentration and hydrophobicity. The model also takes into account the chemical structure and the ionic/non-ionic character of the substance.   2. Bioaccumulation is the net result of relative rates of chemical inputs to an organism from multimedia exposures (e.g., air, food, and water) and chemical outputs (or elimination) from the organism.   3. The model includes mechanistic processes for bioconcentration and bioaccumulation such as chemical uptake from the water at the gill surface (BCFs and BAFs) and the diet (BAFs only), and chemical elimination at the gill surface, fecal egestion, growth dilution and metabolic biotransformation (Arnot and Gobas 2003). Other processes included in the calculations are bioavailability in the water column (only the freely dissolved fraction can bioconcentrate) and absorption efficiencies at the gill and in the gastrointestinal tract.

References

- Arnot JA, Gobas FAPC. 2003. A generic QSAR for assessing the bioaccumulation potential of organic chemicals in aquatic food webs. QSAR and Combinatorial Science 22: 337-345.

- Arnot JA, Mackay D, Parkerton TF, Bonnell M. 2008a. A database of fish biotransformation rates for organic chemicals. Environmental Toxicology and Chemistry 27(11), 2263-2270.

- Arnot JA, Mackay D, Bonnell M. 2008b.Estimating metabolic biotransformation rates in fish from laboratory data. Environmental Toxicology and Chemistry 27: 341-351.

- Meylan, W.M., Howard, P.H, Aronson, D., Printup, H. and S. Gouchie. 1997. "Improved Method for Estimating Bioconcentration Factor (BCF) from Octanol-Water Partition Coefficient", SRC TR-97-006 (2nd Update), July 22, 1997; prepared for: Robert S. Boethling, EPA-OPPT, Washington, DC; Contract No. 68-D5-0012; prepared by: ; Syracuse Research Corp., Environmental Science Center, 6225 Running Ridge Road, North Syracuse, NY 13212.

- Meylan, WM, Howard, PH, Boethling, RS et al. 1999. Improved Method for Estimating Bioconcentration / Bioaccumulation Factor from Octanol/Water Partition Coefficient. Environ. Toxicol. Chem. 18(4): 664-672 (1999). 

- US EPA (2012). On-Line BCFBAF Help File.

 

 

Identified Correction Factors (Appendix E), Biotransformation Fragments and Coefficient values (Appendix F)

 

Reference 3

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

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

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 305 (Bioconcentration: Flow-through Fish Test)

GLP compliance:

not specified

Radiolabelling:

yes

Details on sampling:

- water samples: Samples (8.0 mL) were taken from approximately mid-depth at the centre portion of the exposure vessels and added to 20 mL glass scintillation vials and filled
with scintillant. Three samples were taken in total from vessels containing 10 mussels and from vessels not containing mussels. Water analysis was
conducted, as a minimum, on Day 0 (4 ± 1 hours from the initiation of dosing) and on mussel sampling occasions. No water analysis was conducted on those treatments, which had been depurated. On each sampling occasion, triplicate samples were also taken from the SC, as described for the treatments.

Vehicle:

yes

Details on preparation of test solutions, spiked fish food or sediment:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Radiolabelled and non-radiolabelled materials were mixed, as necessary, to obtain the required nominal concentration (decane: solvent control [SC], 5, 10, 20, 40 and 80 μg l-1; tridecane: SC, 100 μg/L).
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): The test substances were prepared in either dimethylformamide (DMF, decane) or acetone (tridecane), such that the final solvent concentration in the SC and test substance treatments were the same and did not exceed 11 μl/L.

Test organisms (species):

other: Mytilus edulis

Details on test organisms:

TEST ORGANISM
- Source: supplied locally by Brixham Sea Farms (Brixham, UK) from permanently submerged populations from the South Devon coast, in November 2004, June 2005, November 2005 and September 2006.
- Shell length at study initiation (lenght definition, mean, range and SD): decane 26.2 mm (range: 23.0 – 31.0 mm); tridecane 28.1 mm (range: 25.3 – 32.1 mm)
- Method of breeding: The collected mussels were placed in an aquarium with flowing seawater and acclimated in husbandry to the experimental temperature (15 ± 1°C) for at least 48 hours, prior to acclimation in the test system.
- Feeding during test: The test organisms were fed by continuous addition of commercially available cultured unicellular algae, Tetraselmis (Platymonas) sp., to the dilution water, such that the incoming test solution contained a constant nominal algae concentration of typically 6000 to 10000
cells/mL. The tetraselmis suspension was prepared every four days and the cell density of the stocks of the concentrated algae monitored using a Coulter Counter.

ACCLIMATION
- Acclimation period: Mussels were transferred to the test system 48 - 96 hours prior to exposure.
- Acclimation conditions (same as test or not): same
- Type and amount of food: During the acclimation period in husbandry, mussels were fed the unicellular green algae Tetraselmis (Instant Algae® Tetraselmis [Platymonas] sp, Reed Mariculture, USA) in a single feed, at a rate of 20 - 25 mL/day.

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

11 - 14 d

Total depuration duration:

5 d

Test temperature:

15 ± 1 °C

pH:

8.0 ± 0.5

Dissolved oxygen:

> 75% saturation

Salinity:

35 ± 1 ‰

Details on test conditions:

TEST SYSTEM
- Test vessel: The test vessels were borosilicate glass beakers of 2000 mL nominal capacity, fitted with outlets to provide a nominal working volume of 1000 mL.
- Type of flow-through (e.g. peristaltic or proportional diluter): The stock solutions were delivered by syringe pump at a rate of 0.0083 mL/min (decane and tridecane) to mix with dilution water in a chamber of 1250 mL working volume, with magnetic stirring, prior to delivery into a flow splitter (approximately 1000 mL working volume) and finally into the test vessels. Dilution water flow rates were maintained at a rate of 600 ± 60 mL/min. Chemical flow rates were checked daily. Flow rates, through the vessels, were 100 ± 10 mL/min.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 5
- No. of vessels per control / vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: natural seawater taken from Torbay, Devon, UK filtered to <= 5 µm to remove particulate matter
- Holding medium different from test medium: yes
- Intervals of water quality measurement: The dissolved oxygen and pH was measured in one replicate of each treatment, as a minimum, on a twice-weekly basis.

OTHER TEST CONDITIONS
- Photoperiod: 16h light/ 8h dark with staged change of light intensity (20 min) for dawn and dusk periods

RANGE-FINDING / PRELIMINARY STUDY
- Results used to determine the conditions for the definitive study: The test substances were tested at sub-lethal concentrations, as previously ascertained from range-finding studies.

Nominal and measured concentrations:

Decane (nominal): 5, 10, 20, 40 and 80 µg/L
Decane (measured): 2.9, 4.9, 10.3, 21.2 and 50.6 µg/L
Tridecane (nominal): 50 µg/L
Tridecane (measured): 12.2 µg/L

Reference substance (positive control):

no

Lipid content:

7.07 - 7.42 %

Time point:

end of exposure

Remarks on result:

other: tridecane

Lipid content:

4.33 - 6.67 %

Time point:

end of exposure

Remarks on result:

other: decane

Key result

Type:

BCF

Value:

8 930 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: decane

Remarks:

Conc.in environment / dose:2.9 µg/L

Key result

Type:

BCF

Value:

9 120 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: decane

Remarks:

Conc.in environment / dose:4.9 µg/L

Key result

Type:

BCF

Value:

8 090 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: decane

Remarks:

Conc.in environment / dose:10.3 µg/L

Key result

Type:

BCF

Value:

5 280 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: decane

Remarks:

Conc.in environment / dose:21.2 µg/L

Key result

Type:

BCF

Value:

2 055 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: decane

Remarks:

Conc.in environment / dose:50.6 µg/L

Key result

Type:

BCF

Value:

28 100 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: tridecane

Remarks:

Conc.in environment / dose:12.2 µg/L

Metabolites:

not measured

Details on results:

- Mortality of test organisms: No mortality observed
- Mortality and/or behavioural abnormalities of control: none
- Loss of test substance during test period:
- Results with vehicle control:

Reported statistics:

BCF = mean concentration in mussels (µg/kg ww)/mean water exposure concentrations (µg/L)

Water chemistry

Mean measured concentrations of decane and tridecane were approximately half and a quarter of the nominal values, respectively. As mean measured concentrations of less than 80 % of nominal, were recorded for some substances, mean measured concentrations have been used throughout the report. Radioactive counts in the SC were within background levels (< 0.5 Bq) and the limit of detection, in all cases was <= 0.7 µg/L.

Validity criteria fulfilled:

not applicable

Reference 4

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Validated QSAR model. Calculation for component of Hydrocarbons, C11-C13 (odd numbered), n-alkanes

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Test organisms (species):

other: fish

Route of exposure:

aqueous

Test type:

other: calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: BCFBAF v3.01
- Result based on calculated log Pow of: 6.73 (KOWWIN v1.68)

Type:

BCF

Value:

537 L/kg

Basis:

whole body w.w.

Remarks on result:

other: The substance is within the applicability domain of the BCFBAF submodel: Bioconcentration factor (BCF; Meylan et al., 1997/1999).

Type:

BCF

Value:

1 889 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: Upper trophic, incl. biotransformation estimates; The substance is within the applicability domain of the BCFBAF submodel: Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003).

Type:

BAF

Value:

39 900 L/kg

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: Upper trophic, incl. biotransformation estimates; The substance is within the applicability domain of the BCFBAF submodel: Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003).

Details on kinetic parameters:

Biotransformation half-life (days): 7.617
Biotransformation rate (kM, normalised to 10 g fish at 15 °C): -
The substance is within the applicability domain of the BCFBAF submodel: Biotransformation rate in fish (kM; Arnot et al., 2008a/b).

Summary Results:

Log BCF (regression-based estimate): 2.73 (BCF = 537 L/kg wet-wt)

Biotransformation Half-Life (days) : 7.62 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 4.60 (BAF = 3.99e+004 L/kg wet-wt)

 

Experimental BCF-kM Database Structure Match:

--------------------------------------------

Name     : n-tridecane

CAS Num  : 000629-50-5

Log BCF  : ---

BCF Data : ---

Log Bio HL: 1.031 (Bio Half-life = 10.7 days)

Bio Data : kM Training Set

 

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 6.73

 

Equation Used to Make BCF estimate:

Log BCF = 0.6598 log Kow - 0.333 + Correction

 

Correction(s):                   Value

Alkyl chains (8+ -CH2- groups) -1.374

 

Estimated Log BCF = 2.730 (BCF = 537.4 L/kg wet-wt)

 

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 2 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0682

Frag | 2 | Methyl [-CH3]                           | 0.2451 | 0.4902

Frag | 11 | -CH2- [linear]                          | 0.0242 | 0.2661

Frag | 1 | N-Alkane (linear) ... < C22              | 0.0000 | 0.0000

L Kow| * | Log Kow =  6.73 (KowWin estimate)       | 0.3073 | 2.0671

MolWt| * | Molecular Weight Parameter               |        | -0.4728

Const| * | Equation Constant                        |        | -1.5058

============+============================================+=========+=========

RESULT  |       LOG Bio Half-Life (days)           |        | 0.8818

RESULT  |           Bio Half-Life (days)           |        |  7.617

NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |

============+============================================+=========+=========

 

Biotransformation Rate Constant:

kM (Rate Constant): 0.09101 /day (10 gram fish)

kM (Rate Constant): 0.05118 /day (100 gram fish)

kM (Rate Constant): 0.02878 /day (1 kg fish)

kM (Rate Constant): 0.01618 /day (10 kg fish)

 

Note: For Arnot-Gobas BCF & BAF Methods, Experimental Km Half-Life Used:

Exp Km Half-Life = 1.031 days (Rate Constant = 0.06454/ day)

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

Estimated Log BCF (upper trophic) = 3.276 (BCF = 1889 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 4.601 (BAF = 3.993e+004 L/kg wet-wt)

Estimated Log BCF (mid trophic)  = 3.419 (BCF = 2625 L/kg wet-wt)

Estimated Log BAF (mid trophic)  = 4.890 (BAF = 7.756e+004 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 3.462 (BCF = 2897 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 5.064 (BAF = 1.158e+005 L/kg wet-wt)

 

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

Estimated Log BCF (upper trophic) = 4.198 (BCF = 1.577e+004 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 6.974 (BAF = 9.422e+006 L/kg wet-wt)

 

 

Executive summary:

QPRF: BCFBAF v3.01

 

1.	Substance	See “Test material identity”
2.	General information
2.1	Date of QPRF	See “Data Source (Reference)”
2.2	QPRF author and contact details	See “Data Source (Reference)”
3.	Prediction
3.1	Endpoint (OECD Principle 1)	Endpoint	Bioaccumulation (aquatic)
		Dependent variable	- Bioconcentration factor (BCF) - Bioaccumulation factor (BAF; 15 °C) - Biotransformation rate (kM) and half-life
3.2	Algorithm (OECD Principle 2)	Model or submodel name	BCFBAF Submodels: 1) Bioconcentration factor (BCF; Meylan et al., 1997/1999) 2) Biotransformation rate in fish (kM; Arnot et al., 2008a/b) 3) Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003)
		Model version	v. 3.01
		Reference to QMRF	Estimation of Bioconcentration, bioaccumulation and biotransformation in fish using BCFBAF v3.01 (EPI Suite v4.11)
		Predicted value (model result)	See “Results and discussion”
		Input for prediction	Chemical structure via CAS number or SMILES; log Kow (optional)
		Descriptor values	- SMILES: structure of the compound as SMILES notation - log Kow - Molecular weight
3.3	Applicability domain (OECD principle 3)	Domains:
		1) Bioconcentration factor (BCF; Meylan et al., 1997/1999)
		a) Ionic/non-Ionic	The substance is non-ionic.
		b) Molecular weight (range of test data set): - Ionic: 68.08 to 991.80 - Non-ionic: 68.08 to 959.17 (On-Line BCFBAF Help File, Ch. 7.1.3 Estimation Domain and Appendix G)	The substance is within range (184.37 g/mol).
		c) log Kow (range of test data set): - Ionic: -6.50 to 11.26 - Non-ionic: -1.37 to 11.26 (On-Line BCFBAF Help File, Ch. 7.1.3 Estimation Domain and Appendix G)	The substance is within range (6.73).
		d) Maximum number of instances of correction factor in any of the training set compounds (On-Line BCFBAF Help File, Appendix E)	Not exceeded.
		2) Biotransformation rate in fish (kM; Arnot et al., 2008a/b)
		a) The substance does not appreciably ionize at physiological pH. (On-Line BCFBAF Help File, Ch. 7.2.3)	fulfilled
		b) Molecular weight (range of test data set): 68.08 to 959.17 (On-Line BCFBAF Help File, Ch. 7.2.3)	The substance is within range (184.37 g/mol).
		c) The molecular weight is ≤ 600 g/mol. (On-Line BCFBAF Help File, Ch. 7.2.3)	fulfilled
		d) Log Kow: 0.31 to 8.70 (On-Line BCFBAF Help File, Ch. 7.2.3)	The substance is not within range (6.73).
		e) The substance is no metal or organometal, pigment or dye, or a perfluorinated substance. (On-Line BCFBAF Help File, Ch. 7.2.3)	fulfilled
		f) Maximum number of instances of biotransformation fragments in any of the training set compounds (On-Line BCFBAF Help File, Appendix F)	Not exceeded.
		3) Arnot & Gobas BAF and steady-state BCF Arnot & Gobas, 2003)
		a) Log Kow ≤ 9 (On-Line BCFBAF Help File, Ch. 7.3.1)	fulfilled
		b) The substance does not appreciably ionize. (On-Line BCFBAF Help File, Ch. 7.3.1)	fulfilled
		c) The substance is no pigment, dye, or perfluorinated substance. (On-Line BCFBAF Help File, Ch. 7.3.1)	fulfilled
3.4	The uncertainty of the prediction (OECD principle 4)	1. Bioconcentration factor (BCF; Meylan et al., 1997/1999) Statistical accuracy of the training data set (non-ionic plus ionic data): - Correlation coefficient (r^2) = 0.833 - Standard deviation = 0.502 log units - Absolute mean error = 0.382 log units   2. Biotransformation Rate in Fish (kM) Statistical accuracy (training set): - Correlation coefficient (r^2) = 0.821 - Correlation coefficient (Q^2) = 0.753 - Standard deviation = 0.494 log units - Absolute mean error = 0.383 log units   3. Arnot-Gobas BAF/BCF model No information on the statistical accuracy given in the documentation.
3.5	The chemical mechanisms according to the model underpinning the predicted result (OECD principle 5)	1. The BCF model is mainly based on the relationship between bioconcentration and hydrophobicity. The model also takes into account the chemical structure and the ionic/non-ionic character of the substance.   2. Bioaccumulation is the net result of relative rates of chemical inputs to an organism from multimedia exposures (e.g., air, food, and water) and chemical outputs (or elimination) from the organism.   3. The model includes mechanistic processes for bioconcentration and bioaccumulation such as chemical uptake from the water at the gill surface (BCFs and BAFs) and the diet (BAFs only), and chemical elimination at the gill surface, fecal egestion, growth dilution and metabolic biotransformation (Arnot and Gobas 2003). Other processes included in the calculations are bioavailability in the water column (only the freely dissolved fraction can bioconcentrate) and absorption efficiencies at the gill and in the gastrointestinal tract.

References

- Arnot JA, Gobas FAPC. 2003. A generic QSAR for assessing the bioaccumulation potential of organic chemicals in aquatic food webs. QSAR and Combinatorial Science 22: 337-345.

- Arnot JA, Mackay D, Parkerton TF, Bonnell M. 2008a. A database of fish biotransformation rates for organic chemicals. Environmental Toxicology and Chemistry 27(11), 2263-2270.

- Arnot JA, Mackay D, Bonnell M. 2008b.Estimating metabolic biotransformation rates in fish from laboratory data. Environmental Toxicology and Chemistry 27: 341-351.

- Meylan, W.M., Howard, P.H, Aronson, D., Printup, H. and S. Gouchie. 1997. "Improved Method for Estimating Bioconcentration Factor (BCF) from Octanol-Water Partition Coefficient", SRC TR-97-006 (2nd Update), July 22, 1997; prepared for: Robert S. Boethling, EPA-OPPT, Washington, DC; Contract No. 68-D5-0012; prepared by: ; Syracuse Research Corp., Environmental Science Center, 6225 Running Ridge Road, North Syracuse, NY 13212.

- Meylan, WM, Howard, PH, Boethling, RS et al. 1999. Improved Method for Estimating Bioconcentration / Bioaccumulation Factor from Octanol/Water Partition Coefficient. Environ. Toxicol. Chem. 18(4): 664-672 (1999). 

- US EPA (2012). On-Line BCFBAF Help File.

 

 

Identified Correction Factors (Appendix E), Biotransformation Fragments and Coefficient values (Appendix F)

 

Appendix E: BCF Non-Ionic Correction Factors Used by BCFBAF
The Training Set used to derive the BCF Correction Factors listed below contained a total of 431 compounds (see Appendix G for the compound list).  The number of compounds in the training set with logKow values of 1.0 to 7.0 total 396 compounds ... 35 training set compounds have a logKow value greater than 7.0 ... Compounds with logKow less than 1.0 were not used to derive correction factors.
Correction Factor	BCFBAF	No. compounds containing factor in training set	Maximum number of each fragment in any individual compound	No. of instances of each fragment for the current substance
Appendix F: kM Biotransformation Fragments & Coefficient Values				.
The Training Set used to derive the Coefficient Values listed below contained a total of 421 compounds (see Appendix I for the compound list).				.
Fragment Description	Coefficient value	No. compounds containing fragment in total training set	Maximum number of each fragment in any individual compound	No. of instances of each fragment for the current substance
Linear C4 terminal chain  [CCC-CH3]	0,03412373	43	3	2
Methyl  [-CH3]	0,24510529	170	12	2
-CH2-  [linear]	0,02418707	109	28	11
Assessment of applicability domain based on molecular weight and log Kow				.
1. Bioconcentration Factor (BCF; Meylan et al., 1997/1999)				.
Training set: Molecular weights	Ionic	Non-ionic		.
Minimum	68,08	68,08		.
Maximum	991,80	959,17		.
Average	244,00	244,00		.
Assessment of molecular weight	Molecular weight within range of training set.			.
				.
Training set: Log Kow	Ionic	Non-ionic		.
Minimum	-6,50	-1,37		.
Maximum	11,26	11,26		.
Assessment of log Kow	Log Kow within range of training set.			.
				.
2. Biotransformation Rate in Fish (kM; Arnot et al., 2008a/b)				.
Training set: Molecular weights				.
Minimum	68,08			.
Maximum	959,17			.
Average	259,75			.
Assessment of molecular weight	Molecular weight within range of training set.			.
				.
Training set: Log Kow				.
Minimum	0,31			.
Maximum	8,70			.
Assessment of log Kow	Log Kow within range of training set.			.
				.

Description of key information

Hydrocarbons, C11-C13 (odd numbered), n-alkanes is considered to potentially bioaccumulate in organisms.

Additional information

No studies investigating the bioaccumulation potential of Hydrocarbons, C11-C13 (odd numbered), n-alkanes is available. Based on the available data combined in a Weight-of-Evidence (WoE) approach it can be concluded that at least the n-tridecane component of Hydrocarbons, C11-C13 (odd numbered), n-alkanes can be considered as bioaccumulative according to REACh criteria.

Bioaccumulation via aqueous exposure

Based on data for both main components, Hydrocarbons, C11-C13 (odd numbered), n-alkanes is poorly soluble in water (undecane/tridecane: < 0.1 mg/L) and readily biodegradable (see chapter 5.2). According to the Guidance on information requirements and chemical safety assessment, Chapter R.7b, readily biodegradable substances can be expected to undergo rapid and ultimate degradation in most environments, including biological Sewage Treatment Plants (STPs; ECHA 2012a). Thus, after passing through conventional STPs, only a very low concentration of the test substance is likely to be (if at all) released into the environment. The Guidance on information requirements and chemical safety assessment, Chapter R.7b (ECHA 2012a) states that once insoluble chemicals enter a standard STP, they will be extensively removed in the primary settling tank and fat trap and thus, only limited amounts will get in contact with activated sludge organisms. Nevertheless, once this contact takes place, these substances are expected to be removed from the water column to a significant degree by adsorption to sewage sludge based on its high adsorption potential (undecane: log Koc = 3.42, tridecane: log Koc = 3.94) and the rest will be extensively biodegraded (Guidance on information requirements and chemical safety assessment, Chapter R.7a, (ECHA 2012b). Degradation is also expected in the environment since numerous microorganisms showed to be able to metabolize long-chained n-alkanes (e.g., Wentzel et al. 2007) as well as based on numerous studies investigating the biodegradation of crude oil components (e.g., Walker et al. 1976, Leahy and Colwell 1990, Del'Arco et al. 1999). Based on relatively high Henry’s law constants for both components the test substance is expected to volatilize rapidly from water surfaces. 

Considering this one can assume that the availability of the substance in the aquatic environment will be extremely low, which reduces the probability of adsorption and uptake from the surrounding medium into organisms (e. g., see Björk 1995). 

In addition, a bioconcentration study with the structurally very similar substance dodecane is available. A read across from dodecane to undecane and tridecane is considered to be acceptable, since the source and the target substances structurally differ in only one C-atom at the carbon chain, which is not expected to significantly alter the environmental behavior and ecotoxicity profile of the substances. The bioconcentration potential of dodecane was investigated in a study according to OECD guideline 305 using Pimephales promelas as test organism (Tolls et al. 2002). The median concentration of the test substance in the test water was measured to be 0.25 µg/L. The concentration of the test substance in fish did not exceed the method limit of detection of 60 µg/kg. Thus, the upper limit of the BCF is estimated by dividing the method LOD by the exposure concentration and a BCF value of 240 L/kg is derived. This result is interpreted as evidence that bioconcentration from the aqueous phase is negligible.

 

Bioaccumulation via oral uptake

If released into the water phase, however, the substance may to some degree bind to particulate organic matter or biota, and therefore, the main route of exposure for aquatic organisms such as fish or mussels will be via food ingestion or contact with suspended solids.

In absence of a reliable dietary exposure bioaccumulation test the bioaccumulation potential after oral uptake was assessed in a study (CEFIC LRI project) focusing on critical body burden of decane and tridecane in a marine mussel as well as literature data of animal metabolism. In the study, mussels were exposed in a flow-through system to decane and tridecane via the aqueous route (Panter et al. 2008). A solvent was used, which facilitate bioavailability and thus enable an assessment of accumulation in case the substances are taken up by living organisms. Radiolabeled and non-radiolabeled test substance were mixed to obtain the required nominal concentrations of 5 to 80 µg/L for decane and 50 µg/L for tridecane. Test substances were prepared in either dimethylformamide (decane) or acetone (tridecane), such that the final solvent concentration did not exceed 11 µL/L. Mean measured concentrations of decane and tridecane were approximately half and a quarter of the nominal values, respectively. As mean measured concentrations of less than 80 % of nominal, were recorded, mean measured concentrations have been used for BCF calculation (ratio of the measured tissue and water concentrations at the end of the exposure). Decane accumulated in the tissues of the mussels over time, and as the exposure concentration in the water increased there was a concomitant increase in the body residue concentration. Upon transfer of the mussels exposed to the 50.6 µg/L to clean water (depuration), there was minimal elimination of decane over this five day depuration period, with body residue concentrations only decreasing from 0.731 ± 0.092 mM/kg ww on day 6 to 0.702 ± 0.058 mM/kg ww on day 11. The higher BCF was obtained from the lower exposure concentrations but was at all concentrations above 2000. Only one concentration of tridecane was tested, 12.2 µg/L, which was considered to be the maximum that could be tested due to its limit of aqueous solubility. The body residue concentration of the mussels increased continuously throughout the 14 days of exposure, reaching a value of 1.86 ± 0.326 mM/kg ww, with a corresponding measured BCF of 28100.

Since body residues were monitored only by radiolabel, the body concentrations represent parent compound plus any metabolites/transformation products retaining the 14C marker. Thus, the BCF values calculated may be biased and overestimate the bioaccumulation potential. However, the low depuration rate suggests little transformation of accumulated decane to more polar metabolites and tridecane was still accumulating in the tissues of the mussels at the end of the study. Available literature on the metabolism of medium-chained alkanes support this assumption. One study reports that decane is metabolised by mouse liver microsomes in the presence of NADPH and oxygen to decanol, decanoic acid and decamethylene glycol, with the rate of metabolism being very low (Kosuke et al. 1969). This low rate of metabolism is also highlighted in a rat liver microsome study in which metabolic clearance, as assessed by intrinsic clearance, was 4-fold higher for nonane (C9) than decane (C10), and illustrated a negative correlation between metabolic clearance and chain length. No metabolic clearance was observed for tetradecane (Anand et al. 2007). It is likely that the rate of metabolism of decane and similar medium-chained n-alkanes in mussels would be even slower than in mammalian systems (Seibel 2007). Metabolism studies in rainbow trout showed that paraffins in the C13 -C22 range reached a steady equilibrium value in the range of 700 - 900 ppm (Cravedi and Tullez 1983). The most pronounced deposition occurred in the adipose tissue. The significant enhancement of odd- and even-chain saturated fatty acids from C14 to C18 in treated fish, shows that n-alkanes were metabolized by terminal oxidation of the carbon chain. This biotransformation has been previously observed in fish by Roubal (1974) and Whittle et al. (1977). Results of the depuration period study indicated that the n-alkanes longer than C16 were well retained, while the shorter-chained alkane concentration decreased (Cravedi and Tullez 1983). Corner et al. (1976) also demonstrated that in cod, the loss of n-alkanes from the liver, following withdrawal of the hydrocarbons, decreased when the chain length increased. According to these findings it seems that the n-alkanes preferentially accumulated were also the most easily mobilized when the hydrocarbon ingestion ceased.

The assumed accumulation after uptake into organisms is supported by QSAR calculations using BCFBAF v3.01 performed for undecane and tridecane. Whereas BCF values (using the regression method as well as the Arnot-Gobas method) showed to be < 2000 L/kg (undecane: 121 – 1420 L/kg; tridecane: 537 – 1889 L/kg), the BAF values indicated a higher bioaccumulation potential via oral uptake (undecane: 2014 L/kg; tridecane: 39900 L/kg)

Hence, based on the data comprised in this Weight-of-evidence approach, it is reasonable to conclude that at least the n-tridecane component of Hydrocarbons, C11-C13 (odd numbered), n-alkanes has a potential for bioaccumulation via oral uptake as indicated by the high log Kow value. Based on a sound assessment of calculated and experimental data for various n-paraffins done by Lampi et al. (2010, report attached in chapter 13) it can be concluded that Hydrocarbons, C11-C13 (odd numbered), n-alkanes might fulfill the B criterion but not the vB criterion.

References

Anand SS, Campbell JL, Fisher JW. 2007. In vitro rat hepatic metabolism of n-alkanes: Nonane, decane and tetradecane. Intern J Toxicol 26: 325-329

Björk M (1995) Bioavailability and uptake of hydrophobic organic contaminants in bivalve filter-feeders. Ann Zool Fenn 32(2): 237-245

Corner EDS, Harris RP, Whittle KJ, Mackie PR. 1976. Hydrocarbons in marine zooplankton and fish, in: Lockwood APM (ed.).Effects of pollutants on aquatic organisms, Society for Experimental Biology Seminar Series Vol 2, pp.71-105, Cambridge University Press

Cravedi JP, Tullez JE. 1983. Hydrocarbons disposition, lipid content and fatty acid composition in trout after long-term dietary exposure to n-alkanes. Environ Res 32: 398 -413

Del'Arco JP, de Franca FP. 1999. Biodegradation of crude oil in sandy sediments. Int Biodet Biodeg 44: 87-92

ECHA (2012a) Guidance on information requirements and chemical safety assessment, Chapter R.7b: Endpoint specific guidance, version 2.2 (August 2013), Helsinki, Finland

ECHA (2012b) Guidance on information requirements and chemical safety assessment, Chapter R.7a: Endpoint specific guidance, version 1.2 (November 2012), Helsinki, Finland#

Kosuke I, Emi K, Masamichi K. 1969. Microsomal hydroxylation of decane.Biochimica et Biophysica Acta (BBA)-Lipids and Lipid Metabolism 176(4): 713-719

Leahy JG, Colwell RR. 1990. Microbial degradation of hydrocarbons in the environment. Microbiol Rev 54(3): 305-315

Panter GH, Gillings E, Sharpe, AD, Thompson RS. 2008.Report No BL8547/A Copy number Critical body burden of decane, tridecane, and chlorinated tridecane in the marine mussel, Mytilus edulis. CEFIC LRI project No. BL8547/A

Roubal WT. 1974. In vivo and in vitro spin-labeling studies of pollutants host interaction. in: Hague R and Biros FJ (eds.), Mass spectrometry and NMR spectroscopy in pesticide chemistry, pp. 303 -323, Plenum, New York

Seibel BA. 2007. On the depth and scale of metabolic rate variation: scaling of oxygen consumption rates and enzymatic activity in the class Cephalopoda (Mollusca). J Experiment Biol 210: 1-11

Tolls J, van Dijk J. 2002. Bioconcentration of n-dodecane and its branched isomer 2,2,4,6,6-pentamethylheptane in fathead minnows. Chemosphere 47: 1049-1057

Walker JD, Colwell RR, Petrakis L. 1976. Biodegradation rates of components of petroleum. Can J Microbiol 22(8): 1209-1213

Wenzel A, Ellingsen TE, Kotlar HK, Totchev SB, Throne-Holst M. 2007. Bacterial metabolism of long-chained n-alkanes. Appl Microbiol Biotechnol 76: 1209-1221

Whittle KJ, Murray J, Mackie PR, Hardy R, Farmer J. 1977. Fate of hydrocarbons in fish. in: Petroleum hydrocarbons in the marine environment, Rapp P V Reun Cons Int Explor Mer 171: 139 -142