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

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

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 microorganisms is presented in the Endpoint summary for Toxicity to microorganisms and the accompanying files are also attached there.

Reason / purpose for cross-reference:

read-across source

Water media type:

freshwater

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

60 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: linear regression was applied

Validity criteria fulfilled:

yes

Remarks:

adequate and reliable documentation on the read across is provided

Conclusions:

Intreleven aldehyde is concluded to have an 3h EC50 value of 60 mg/L, based on the result of the read across substance 10-Undecenal.

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 March 2012 - 25 May 2012

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 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

Version 4 April 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

The test substance is not soluble enough in water to allow the preparation of an aqueous stock solution in tap water. Different stock solutions were prepared by dissolution of Intreleven aldehyde Food Grade in ethanol in order to add always the same volume (i.e. 5 ml) of ethanol in each cylinder.

The following solutions were prepared:

A1: 10.00 g/I; prepared by dissolving of 1000 mg of Aldehyde C11 Undecylenic Food Grade in 100 ml ethanol.

A2: 3.16 g/I; prepared by dissolving of 316 mg of Aldehyde C11 Undecylenic Food Grade in 100 ml ethanol.

A3: 1.00 g/I; prepared by diluting 2 ml of stock solution A 1 to a total volume of 20 ml with ethanol

A4 : 0.32 g/I; prepared by diluting 2 ml of stock solution A2 to a total volume of 20 ml
with ethanol.

A5 : 0.10 g/I; prepared by diluting 2 ml of stock solution A3 to a total volume of 20 ml with ethanol.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge was obtained from a water treatment plant treating predominantly domestic sewage (Bois-de Bay, 1242 Satigny , Switzerland). The sludge was kept aerobic until being used on the same day. The pH was between 7 and 8. The suspended solids content was determined by drying and weighing 50 ml of the sludge: dry weight of suspended solids: 3.885 g/I. By adding 200 ml of sludge to the 500-ml test vessels, the final concentration of suspended solids was 1.55 g/I, i.e. in the range 0.8 to 1.6 g/I as recommended in ISO 8192-1986.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

The whole experiment was carried out at 20 ± 2°C (temperature controlled water bath).

pH:

After 3 hours:
Control: 8.02- 8.03
Test item: 8.01-8.05
Reference substance: 7.98-7.99

Dissolved oxygen:

After 3 hours (Initial-final):
control: 1.40-1.60 mg/L
test item: 0.90-2.80 mg/L
reference substance: 1.25-1.30 mg/L

Nominal and measured concentrations:

Test substance: Nominal: 1.0, 3.2, 10, 31.6, 100 mg/L
Reference substance: Nominal: 5 and 30 mg/L

Details on test conditions:

At time "0", in a 500-ml scaled cylinder, 16 ml of the synthetic sewage feed and 5 ml ethanol was made up to 300 ml with water. 200 ml of sludge were added and the mixture was aerated continuously for 3 hours by bubbling air into it (first control).

At time 15 minutes, the same was repeated except that 5ml of test substance stock solution was added in place of the ethanol. This process was repeated at 15 minute intervals with 5ml of the different test substance stock solution (see details on test solution). This was then followed by the reference vessels. In another 500-ml cylinder, 16 ml of the synthetic sewage feed + 5 ml or 30 ml of 3,5-dichlorophenol stock solution + 5 ml ethanol were made up to 300 ml with water. 200 ml of sludge were added and the mixture was aerated. Finally two further control vessels were prepared.

Measurements of the oxygen consumption: at time "3 hours", the pH of the first cylinder control was measured. The content was used to fill up the BOD flask which was closed with the 02-electrode and the measurement of the oxygen consumption was started for about 10 minutes. The same procedure was repeated every 15 minutes for each cylinder in the order they had been prepared, so that the contact time is three hours for each of them.

The whole experiment was carried out at 20 ± 2°C (temperature controlled water bath).

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

60 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: linear regression applied

Results with reference substance (positive control):

The EC50 (3 hours) of 3,5-dichlorophenol was 21.68 mg/L.

Reported statistics and error estimates:

For estimating the EC50 (3 hours) a linear relationship between % inhibition and the common logarithm of the test substance concentration was assumed for concentrations ranging from 31.6 mg/I to 100 mg/I (see attached graph). A linear regression was performed (least squares method) and parameters a and b were obtained:
% inhibition = a * log cone. + b
a = 103.269 b = -136.537

Nominal Concentration (mg/L)		pH	∆O2 (mg/L)	Time (min)	Rate	% inhibition
Control	0	8.03	1.60	2.50	0.64
	0	8.02	1.40	2.50	0.56
3,5-dichlorophenol	5.0	7.98	1.30	2.50	0.52	13.3
	30.0	7.99	1.25	5.00	0.25	58.3
Test item	100.0	8.05	0.90	5.00	0.18	70.0
	31.6	8.03	2.45	5.00	0.49	18.3
	10.0	8.01	2.80	5.00	0.56	6.7
	3.2	8.04	1.60	2.50	0.64	-6.7
	1.0	8.05	2.80	5.00	0.56	6.7

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were met: the difference between the initial control and the final control respiration rates was min. 15% (13.3%) and the EC50 (3 hours) of 3,5 - dichlorophenol was between 5 and 30 mg/L (21.68 mg/L).

Conclusions:

The effect of 10-Undecenal on the respiration of activated sewage sludge micro-organisms gave an EC50 (3 hours) value of 60 mg/L.

Executive summary:

A study was performed to assess the effect of 10-Undecenal on the respiration of activated sewage sludge. The study was performed according to OECD TG 209 guideline and GLP. The validity criteria for the 1984 guideline were all met. Activated sewage sludge was exposed to an aqueous dispersion of the test item at concentrations of 1.0, 3.2, 10, 31.6 and 100 mg/L for a period of 3 hours at measured temperatures of 20 ± 2°C with the addition of a synthetic sewage as a respiratory substrate. The rates of respiration were measured electrochemically for each culture. The effect of the test item on the respiration of activated sewage sludge gave a 3 hour EC50 value of 60 mg/L.

Description of key information

The 3h EC50 for micro-organisms for Intreleven aldehyde was 60 mg/L, based on the result of the read across substance 10-Undecenal.

Key value for chemical safety assessment

EC50 for microorganisms:

60 mg/L

Additional information

The microorganism toxicity information for Intreleven aldehyde is derived from 10 -Undecenal, a close analogue. First the microorganism study of 10 -Undecenal will be summarized below. Thereafter, the read-across justification is presented. The accompanying files are also attached here in the Endpoint summary.

The OECD 209 microorganism toxicity study with 10 -Undecenal used for read-across to Intreleven aldehyde:

A study was performed to assess the effect of 10-Undecenal on the respiration of activated sewage sludge. The study was performed according to OECD TG 209 guideline and GLP. The validity criteria for the 1984 guideline were all met. Activated sewage sludge was exposed to an aqueous dispersion of the test item at concentrations of 1.0, 3.2, 10, 31.6 and 100 mg/L for a period of 3 hours at measured temperatures of 20 ± 2°C with the addition of a synthetic sewage as a respiratory substrate. The rates of respiration were measured electrochemically for each culture. The effect of the test item on the respiration of activated sewage sludge gave a 3 hour EC50 value of 60 mg/L.

Intreleven aldehyde (CAS 58296-81-4; Target) and its toxicity for microorganisms using read across information from Undec-10-enal (CAS 112-45-8; 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 toxicity data for microorganisms are available. Therefore additional information is used in accordance with Article 13 of REACH where it is said that lacking information can be generated whenever possible by means of applying alternative methods such as in vitro tests, SARs, grouping and read-across. For assessing the aquatic toxicity of Intreleven aldehyde to microorganisms the analogue approach is selected because for one closely related analogue, Undec-10-enal, an aquatic toxicity study (sludge microorganisms) is available which can be used for read across.

Hypothesis: Intreleven aldehyde is expected to have similar toxicity to sludge microorganism as its analogue, Undec-10-enal. 

Available experimental information: For the structurally related source chemical, Undec-10-enal, a microorganism guideline toxicity test (OECDTG209, GLP) is available. The study is considered reliable (K1) and can be used for assessment purposes. The 3h EC50 for micro-organisms was 60 mg/L. 

Target and Source chemical(s):

Chemical structures of the target chemical (Intreleven aldehyde) and the source chemical (Undec-10-enal) are shown in the data matrix below, including physico-chemical properties and toxicological information, considered relevant for the aquatic toxicity.

Purity / Impurities:

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

Analogue 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: Undec-10-enal was selected as analogue because it is one of the main constituents of Intreleven aldehyde for which sludge microorganism toxicity data is available.

Structural similarities and differences: The target chemical, Intreleven aldehyde and the source chemical, Undec-10-enal have a similar linear carbon backbone with a C=C double bond, the same number of carbons and the same functional aldehyde group. The only structural difference is the position of the double bond in the carbon chain of the substances. Some of the constituents of Intreleven aldehyde have the double bond in the chain, while the source substance has it at the end of its chain.

Bioavailability: The target and the source chemical have similar bioavailability. The molecular weights of the target and source are identical (168.28). Both the measured water solubility (26 and 21.5 mg/L for target and source, respectively) and measured log Kow (4.5 and 4.67, respectively) are highly similar.

Mode of Action and the prediction of the aquatic toxicity information: The target and source substance are expected to have the same mode of action, because they are both aldehydes (same linearity and length). In addition, both are shown to be readily biodegradable, showing that the toxicity of the substance does not hinder its biodegaradability.

Remaining uncertainties: There are no remaining uncertainties based on the reasoning presented above. 

Data matrix

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

Final conclusions for aquatic toxicity to sludge microorganisms

For assessing the toxicity for sludge microorganisms a read across is done for Intreleven aldehyde (target) from Undec-10-enal (source). When using read across the result derived should be applicable for C&L and/or risk assessment and be presented with adequate and reliable documentation, which is shown in the present document. The 3h EC50 of Undec-10-enal for microorganisms was found to be 60 mg/L and can be used directly for Intreleven aldehyde. 

Final conclusion on hazard: For Intreleven aldehyde the 3h EC50 for microorganisms is 60 mg/L.

 

Data matrix for the read across from Undec-10-enal to Intreleven aldehyde

CHEMICAL NAME	Intreleven aldehyde (Undec-8-enal)	Undec-10-enal
Molecular structure
CAS	58296-81-4	112-45-8
REACH registration	To be registered (Annex VIII)	Registered (2016)
Einecs/EC number	261-202-4	203-973-1
Molecular formula	C11H20O	C11H20O
Molecular weight	168.28	168.28
Physico-chemical properties
Appearance	Liquid	Colorless liquid
Melting point (°C)	<-20 (IFF, 2016)	<-16.6 (ECHA disseminated)
Boiling point (°C)	239.1 (IFF, 2016)	179 (ECHA disseminated)
Vapour pressure (Pa)	6.04 (IFF, 2016)	8.71(ECHA disseminated)
Water solubility (mg/L)	26.1 (IFF, 2016)	21.52 (ECHA disseminated)
LogKow	4.47 (IFF, 2017)	4.67 (ECHA disseminated)
Environmental fate
Biodegradability	Readily biodegradable (read across from Floral Super)	Readily biodegradable (ECHA disseminated)
Ecotoxicological information
Acute aquatic toxicity
OECD TG209 Micro-organisms (3h EC50) (mg/L)	60 (read across from Undec-10-enal)	60