Reaction mass of undec-8-enal and undec-9-enal and undec-10-enal

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The result derived from read across is sufficiently reliable because all Annex XI criteria are met.

Justification for type of information:

The read across justification for biodegradation is presented in the Endpoint summary Biodegradation in water: screening tests and the accompanying files are also attached there.

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (O2 consumption)

Value:

84

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

81

Sampling time:

21 d

Parameter:

% degradation (O2 consumption)

Value:

81

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

55

Sampling time:

7 d

Details on results:

The substance is biodegraded by 84% on day 28 in the Closed Bottle test. Over 60% biodegradation was achieved in a period of 7 days immediately following the attainment of 10% biodegradation. The test item therefore fulfilled the 14-day time window criterion for ready biodegradable compounds and hence the substance should be classified as readily biodegradable.

Validity criteria fulfilled:

yes

Remarks:

adequate and reliable documentation on the read across is provided

Interpretation of results:

readily biodegradable

Conclusions:

Based on the results of the study for the read-across substance Floral Super, Intreleven aldehyde is concluded readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8th of April 2015 until 7th of May 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The information is used for read across to Intreleven aldehyde.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

natural water

Details on inoculum:

River water was sampled from the Rhine near Heveadorp, The Netherlands. The river water was aerated for 7 days to reduce the endogenous respiration. River water without particles was used as inoculum. The particles were removed by sedimentation after 1 day while moderately aerating. The river water was spiked with mineral salts. Ammonium chloride wasa not added to the river water to prevent nitrification.

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

as a percentage of ThOD

Details on study design:

Test bottles:
The test was performed in 0.30 L BOD (biological oxygen demand) bottles with glass stoppers.

Nutrients, stocks and administration:
The nutrient medium of the Closed Bottle test contained per liter of deionized water; 8.5 mg KH2PO4, 21.75 mg K2HPO4, 33.3 mg Na2HPO4·2H2O, 22.5 mg MgSO4·7H2O, 27.5 mg CaCl2, 0.25 mg FeCl3·6H2O. Accurate administering of the test substance was accomplished by preparing a solid stock of 3.0 mg of the test substance per g of silica gel in a 50-mL serum flask. Only part of the top layer of the silica gel was brought into contact with the test substance. The serum flask was closed with a screw top with aluminium foil and the content was mixed vigorously. Subsequently 0.2 g of silica gel with the test substance was added to the test bottles. The resulting concentration of test substance in the bottles was 2.0 mg/L. Next the bottles were filled with nutrient medium with inoculum and closed. Sodium acetate was added to the bottles using a stock solution of 1.0 g/L.

Test procedure:
Use was made of 10 bottles containing only river water, 10 bottles containing river water and silica gel, 10 bottles containing river water and silica gel with test substance, 6 bottles with river water and sodium acetate. The concentrations of the test substance, and sodium acetate in the bottles were 2.0 and 6.7 mg/L, respectively. Each of the prepared solutions was dispensed into the respective group of BOD bottles so that all bottles were completely filled without air bubbles. The zero time bottles were immediately analyzed for dissolved oxygen using an oxygen electrode. The remaining bottles were closed and incubated in the dark. Two duplicate bottles of all series were withdrawn for analyses of the dissolved oxygen concentration at day 7, 14, 21, and 28.

Test conditions:
The pH of the media was 8.0 at the start of the test. The pH of the medium at day 28 was 7.9 (test) and 8.0 (controls). Temperatures were within the prescribed temperature range of 22 to 24°C.

Reference substance:

acetic acid, sodium salt

Remarks:

purity > 99%

Test performance:

The test is valid as shown by an endogenous respiration of 1.2 mg/L on day 28. Furthermore, the differences of the replicate values on day 28 were less than 20%. Sodium acetate was degraded by 88% of its theoretical oxygen demand after 14 days. Degradation of sodium acetate was not inhibited by the test substance. Finally, the most important criterion was met by oxygen concentrations >0.5 mg/L in all bottles during the test period.

Key result

Parameter:

% degradation (O2 consumption)

Value:

84

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

81

Sampling time:

21 d

Parameter:

% degradation (O2 consumption)

Value:

81

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

55

Sampling time:

7 d

Details on results:

The substance is biodegraded by 84% on day 28 in the Closed Bottle test. Over 60% biodegradation was achieved in a period of 7 days immediately following the attainment of 10% biodegradation. The test item therefore fulfilled the 14-day time window criterion for ready biodegradable compounds and hence the substance should be classified as readily biodegradable.

Results with reference substance:

The biodegradation percentage of the reference compound, sodium acetate, on day 14 was 88.

Toxicity to inoculum:

Inhibition of the degradation of a well degradable compound e.g. sodium acetate by the test compound in the Closed Bottle test was not determined because possible toxicity of the test substance to microorganisms degrading acetate is not relevant. Inhibition of the endogenous respiration of the inoculum by the test substance tested was not detected. Therefore, no inhibition of the biodegradation due to the high initial concentration of the test compound is expected.

Validity criteria fulfilled:

yes

Remarks:

Endogenous respiration of 1.2 mg/L on day 28; differences of the replicate values on day 28 were < 20%; reference was degraded by 88% after 14 days; oxygen concentrations >0.5 mg/L in all bottles during the test period.

Interpretation of results:

readily biodegradable

Conclusions:

The substance was biodegraded by 84% on day 28 in the Closed Bottle test, meeting the 14-day window, and should therefore be classified as readily biodegradable.

Executive summary:

In order to assess the biodegradation of Floral Super, a screening test was performed according to OECD TG 301D (Closed Bottle test) and under GLP conditions. In this study river water was exposed to 2 mg/L of the substance for 28 days. Floral Super did not cause a reduction in the endogenous respiration. Furthermore, the validity criteria of the test were met. Floral Super was biodegraded by 84% on day 28 in the standard Closed Bottle screening test, meeting the 14-day window, and should therefore be classified as readily biodegradable.

Description of key information

Biodegradation: readily biodegradable (read-across from Floral Super (CAS number 71077-31-1) tested in OECD TG 301D).

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The biodegradation information for Intreleven aldehyde is derived from Floral Super (CAS# 71077-31 -1), a close analogue. First the biodegradation study of Floral Super will be summarized below. Thereafter, the read-across justification is presented. The accompanying files are attached in the study record.

Based on the results of the study for the read-across substance Floral Super, Intreleven aldehyde is concluded readily biodegradable.

The OECD 301D biodegradation study with Floral Super used for read-across to Intreleven aldehyde:

In order to assess the biodegradation of Floral Super, a screening test was performed according to OECD TG 301D (Closed Bottle test) and under GLP conditions. In this study river water was exposed to 2 mg/L of the substance for 28 days. Floral Super did not cause a reduction in the endogenous respiration. Furthermore, the validity criteria of the test were met. Floral Super was biodegraded by 84% on day 28 in the standard Closed Bottle screening test, meeting the 14-day window, and should therefore be classified as readily biodegradable.

Intreleven aldehyde (CAS 58296-81-4; Target) and its biodegradability in water using read across information from Floral Super (CAS 71077-31-1; Source)

 

Introduction and hypothesis for the read across

Intreleven aldehyde is a multi-constituent which consists of the following main constituents: Undec-10-enal, (9E) Undec-9-enal, (9Z) Undec-9-enal and (8E) Undec-8-enal. These constituents are aldehydes with a linear carbon backbone and contain one C=C double bond at various positions ranging from C 8 to 10. For this substance no experimental data on biodegradation in water are available. Therefore additional information is used in accordance with Article 13 of REACH where it is said that lacking information can be generated by applying alternative methods such as in vitro tests, SARs, grouping and read-across. For assessing the biodegradation of Intreleven aldehyde (target) in water the analogue approach is selected because for one closely related analogue, Floral Super, reliable data on biodegradation in water are available which can be used for read across.

Hypothesis: Intreleven aldehyde is expected to have similar biodegradability in water as its analogue Floral Super.

Available experimental information: The source chemical Floral Super has biodegradability information from a reliable OECDTG301D screening test (K1). The biodegradation reached 84% after 28 days, meeting the 14-day window. The substance is therefore readily biodegradable.

Target and Source chemical(s):

Chemical structures of the target chemical (Intreleven aldehyde) and the source chemical (Floral Super) are shown in data matrix, including physico-chemical properties and other information, considered relevant for the biodegradability of both substances.

Purity / Impurities:

The known constituents and purity of the target chemical do not indicate properties with regard to biodegradation other than indicated by the source substance.

Analogue approach justification

According to REACH Annex XI, an analogue approach can be used to replace testing when information from different sources provides sufficient evidence. The result derived should be applicable for C&L and/or risk assessment and be presented with adequate and reliable documentation.

Analogue selection: Floral Super was selected as an analogue, because it has just one carbon more than Intreleven aldehyde and the same functional group. It is a substance from IFF‘s portfolio, for which adequate data on biodegradation are available.

Structural similarities and differences: The target chemical, Intreleven aldehyde, and the source chemical, Floral Super, have a similar carbon backbone and have the same functional aldehyde group. The main central backbone of Floral Super is one carbon shorter, but it has one additional methyl group and one additional ethyl group with unsaturated carbon bond. The source substance is expected to be slightly more difficult to biodegrade than the target substance because of the branching of Floral Super.

Bioavailability: The molecular weights of the target and source are very similar (168.28and180.29, respectively). Also the physico-chemical properties of Intreleven aldehyde and Floral Super are very similar: the measured water solubility (26 and 29 mg/L, respectively) and the measured log Kow (both 4.5).

Biodegradability: Because of the similarity in structure, it is expected that both substances will present similar biodegradability behavior.

Remaining uncertainties: There are no remaining uncertainties because Intreleven aldehyde (target) is a structurally close analogue to Floral Super (source). This is additionally supported by comparable EPISuite predictions for the substances - BIOWIN5: 0.98 vs 0.76; BIOWIN6: 0.97 vs 0.86 for Intreleven aldehyde and Floral Super, respectively.

Data matrix

The relevant information on physico-chemical properties and toxicological characteristics are presented in the data matrix below.

Conclusions for biodegradation

When using read across the result derived should be applicable for the PBT assessment, C&L and/or risk assessment and be presented with adequate and reliable documentation, which is shown in the present document. The source substance Floral Super is readily biodegradable (OECD TG 301D) and therefore the target substance Intreleven aldehyde is also readily biodegradable.

Final conclusion on ready biodegradability: Intreleven aldehyde is ‘readily biodegradable’.

Data matrix for the read across from Floral Super to Intreleven aldehyde

CHEMICAL NAME	Intreleven aldehyde, (Undec-8-enal)	Floral Super 4,8-dimethyldeca-4,9-dienal
Molecular structure
CAS	58296-81-4	71077-31-1
REACH registration	To be registered (Annex VIII)	Registered (2016)
Einecs/EC-number	261-202-4	275-174-6
Molecular formula	C11H20O	C12H20O
Molecular weight	168.28	180.29
Physico-chemical properties
Appearance	Liquid	Liquid
Melting point (°C)	<-20 (IFF, 2016)	<-20 (IFF, 2014)
Boiling point (°C)	239.1 (IFF, 2016)	242.9 (IFF, 2014)
Vapour pressure (Pa)	6.04 (IFF, 2016)	1.66 (IFF, 2014)
Water solubility (mg/L)	26.1 (at 24°C) (IFF, 2016)	29 (at 22°C) (IFF, 2014)
LogKow	4.47 (IFF 2017)	4.5 (IFF, 2014)
Biodegradation
OECD TG 301D 28 d (% biodeg)	readily biodegradable (read across from Floral Super)	84 (readily biodegradable)
EpiSuite BIOWIN5	0.98 (readily biodegradable)	0.76 (readily biodegradable)
EpiSuite BIOWIN6	0.97   (readily biodegradable)	0.86  (readily biodegradable)