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

Endpoint summary

Description of key information

In the table below the aquatic toxicity data are summarised

Species	Guideline	Result in mg/L	Remarks
Oncorhynchus mykiss	Read across	96h LC50 = 1.45 based on geometric mean measured concentrations	Key study, Rel. 2 based on read across from Decanal tested in   OECD TG 203
Daphnia magna	Read across	48h EC50 = 1.4, based on mean initial measured concentrations	Key study, Rel. 2 based on read across from Floral Super tested in   OECD TG 202
Pseudokirchneriella subcapitata	Read across	72h ErC50 = 1.6 72h ErC10 = 0.45, based on average measured exposure concentrations	Key study, Rel.2 based on read across from Floral Super tested in   OECD TG 201
Microorganisms	Read across	3 hr EC50 = 60 mg/L	Key study, Rel.2 based on read across from 10-Undecenal tested in OECD TG 209

 

No recalculation of the values from read across substances to Intreleven aldehyde was applied, as this would not result in an impact for the C&L. The original LC50 values of the source substances were therefore maintained.

Additional information

Intreleven aldehyde (CAS58296-81-4; Target) and its aquatic toxicity for freshwater algae and invertebrates 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 aquatic toxicity data (algae and Daphnia) 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 algae and Daphnia, the analogue approach is selected because for one closely related analogue, Floral Super, aquatic toxicity studies are available which can be used for read across.

Hypothesis: Intreleven aldehyde is expected to have similar algae and Daphnia toxicity as its analogue, Floral Super.

Available experimental information: For the structurally related source chemical, Floral Super, both an algae and Daphnia guideline toxicity test are available. The studies are considered reliable (K1) and can be used for assessment purposes. The 48h EC50 for Daphnia was 1.4 mg/L, and for algae the 72h ErC50 and 72h ErC10 were 1.6 and 0.45 mg/L, respectively.

Target and Source chemical(s):

Chemical structures of the target chemical (Intreleven aldehyde) and the source chemical (Floral Super) 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 algal or daphnid toxicity 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: 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 algae and daphnid toxicity are available.

Structural similarities and differences: The target chemical, Intreleven aldehyde (Undec-8-enal) and the source chemical, Floral Super (4,8-dimethyldeca-4,9-dienal) 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 an unsaturated carbon bond..

Bioavailability: The molecular weights of the target and source are very similar (168.28 and 180.29, 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).

Mode of Action and the prediction of the aquatic toxicity information: The target and source substances are expected to have the same mode of action, because they are both aldehydes.

Remaining uncertainties: There are no remaining uncertainties based on the reasoning presented above. Differences in log Kow and molecular weight values between target and source are insignificant.

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 freshwater algae and invertebrates

For assessing the acute toxicity for algae and Daphnia and the chronic toxicity for algae a read across is done for Intreleven aldehyde (target) from Floral Super (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 ecotoxicity of Intreleven aldehyde results in a 72h-ErC50 and ErC10 for algae of 1.6 mg/L and 0.45 mg/L respectively and the 48h EC50 for daphnids of 1.4 mg/L. These values can be directly used for Intreleven aldehyde because the differences in logKow and molecular weight are considered insignificant, soconversion is not considered necessary.

Final conclusion on hazard: For Intreleven aldehyde, the 72h-ErC50 and ErC10 for algae and the EC50 for daphnids are 1.6 mg/L, 0.45 mg/L and 1.4 mg/L, respectively.

 

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

CHEMICAL NAME	Intreleven aldehyde (Undec-8-enal)	Floral Super (4,8-dimethyl-4,9-decadienal)
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
Appearances	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)
Aquatic toxicity
Fish 96h LC50 (mg/L)	1.45 (read across from Decanal)	Not available
Daphnia 48h EC50 (mg/L)	1.4 (read across from Floral Super)	1.4
Algae 72h ErC50 (mg/L)	1.6 (read across from Floral Super)	1.6
Chronic toxicity
Algae 72h ErC10 (mg/L) (measured)	0.45 (read across from Floral Super)	0.45