Alkenes, C11-12, hydroformylation products, low boiling

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.003 mg/L

Assessment factor:

5

Extrapolation method:

assessment factor

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0 mg/L

Assessment factor:

50

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

1.12 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:

no exposure of sediment expected

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no exposure of soil expected

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Alchisor TAL 123 is characterized by three constituents: Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), undecan-1-ol and dodecan-1-ol. In a conservative approach the most sensitive PNEC from across the three constituent/constituent categories has been identified and used to address each endpoint in question. The PNEC freshwater is based on the PNEC for dodecan-1-ol and is 0.0028 mg/L, using an AF of 5. The basis of the PNECmarine is the same study for dodecan-1 -ol with an AF of 50 (PNEC is 0.00028 mg/L). Due to the paucity of toxicity data for sediment and soil organisms across the three constituent categories of Alchisor TAL 123 substances, the PNECwater was extrapolated for undecan-1 -ol and dodecan-1 -ol to provide indicative PNECs for sediment and soil compartments based on the underpinning dossiers. PNEC sediment and soil were derived for Alchisor TAL 123 using the equilibium partitioning method in EUSES for the purposes of the CSA. As a similar extrapolation was not appropriate for the C9 -C14 aliphatics, a PNEC for Alchisor TAL 123 is not formally proposed. Experimental evidence for birds and mammals indicates that Alchisor TAL 123 and its constituents are unlikely to present a hazard to birds and a PNECoral is waived.

In summary, it can be seen that Alchisor TAL 123 is characterized by three constituents: Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), undecan-1-ol and dodecan-1-ol and where data exist, receptors in the environmental compartment are likely to be most sensitive to the dodecan-1 -ol constitutent.

Conclusion on classification

After the initial registration, the registrant sought to refine the approach to provide a more realistic assessment of the environmental toxicity of the substance. In light of this reassessment and based on the component results, The registrant proceeded to conduct aquatic toxicity studies on the two most sensitive trophic levels (Daphnia and algae) on the substance Alkenes, C11-12, hydroformylation products, low boiling, EC No 932-235-8 (tradename: Alchisor TAL 123). Results from these studies for Alchisor TAL 123 were used to determine its environmental classification under the 2nd ATP to the CLP Regulation.

Complex UVCB substances such as Alchisor TAL 123 are mixtures of different components (primarily hydrocarbons) exhibiting a variety of physico-chemical properties. When released in the environment, the components in these mixtures will behave differently according to their specific properties (e.g. water solubility, vapour pressure, logKow). This behavior will define their environmental fate and toxicity. To address this issue, CONCAWE (the oil producers’ trade organization) developed the Water Accommodated Fraction (WAF) methodology in the early 1990s. In this methodology, different loadings of the substance are added to the test medium and equilibrium between the water and the hydrocarbons is achieved according to their specific water solubility. The hydrocarbon concentrations at equilibrium will be characteristic of the loading of the substance, and therefore toxicity values from WAF studies are expressed as effect loadings or lethal loadings (EL or LL), not as concentrations. The WAF methodology is widely accepted for the testing of complex hydrocarbon substances and other UVCBs, and it has been incorporated in different guidance documents, including the REACH guidance:

• CONCAWE report 92/56 (1992): ecotoxicological testing of petroleum products https://www.concawe.eu/content/default.asp?PageID=569

• OECD Series on Testing and Assessment, no. 27 (2001): Guidance Document on the Use of the Harmonised System for the Classification of Chemicals which are Hazardous for the Aquatic Environment. Paragraph 71.

• International Maritime Organization GESAMP EHS 28 Document (1993) Guidelines for aquatic toxicity testing of mixtures containing compounds of low water solubility.

• REACH endpoint guidance, chapter 7b: considerations for substances with many components, Table 7-8-3, page 71. The REACH guidance specifically states “the acute lethal loading level (typically expressed as the E(L)L50) is comparable to L(E)C50 values determined for pure substances tested within their solubility range. It may therefore be used directly for classification.” http://echa.europa.eu/documents/10162/13632/information_requirements_r7b_en.pdf

• Globally Harmonized System of Classification and Labelling of Chemicals (GHS), fourth revised edition (2011): Annex 9 (Guidance on Hazards to the Aquatic Environment), Difficult to test substances. On page 484, it is stated that “Many substances covered by the classification scheme are in fact mixtures, for which measurement of exposure concentrations is difficult, and in some cases impossible. Substances such as petroleum distillate fractions, polymers, substances with significant levels of impurities, etc can pose special problems since the toxic concentration is difficult to define and impossible to verify. Typical testing procedures often rely on the formation of a Water Soluble Fraction (WSF) or Water Accommodated Fraction (WAF) and data are reported in terms of loading rates. These data may be used in applying the classification criteria.”

• ECHA Guidance on the Application of the CLP Criteria, version 3.0 (2012): Annex I Aquatic Toxicity, section 4.5 on Complex substances. The REACH guidance specifically states that “complex substances are characterized by a range of chemical structures, frequently in a homologous series, but covering a wide range of water solubilities and other physicochemical characteristics. On addition to water, equilibrium will be reached between the dissolved and undissolved fractions which will be characteristic of the loading of the substance. For this reason, such complex substances are usually tested as a WSF or WAF, and the L(E)C50 recorded based on the loading or nominal concentrations. Analytical support data are not normally available since the dissolved fraction will itself be a complex mixture of components. The toxicity parameter is sometimes referred to as LL50, related to the lethal loading level. This loading level from the WSF or WAF may be used directly in the classification criteria.”

Since Alchisor TAL 123 is a UVCB substance with low solubility, the aquatic studies were conducted using WAFs as recommended. The results were 48 hr Daphnia magna EL50 = 43.3 mg/L, 72 hr Pseudokirchneriella subcapitata EL50 = 14.6 mg/L and 72 hr Pseudokirchneriella subcapitata NOELR = 3.75 mg/L. These studies indicated that Alchisor TAL 123 is not toxic to Daphnia or algae at less than 1 mg/L; and we conclude that it requires no Aquatic Acute Hazard Category classification.