Alkenes, C11-12, hydroformylation products, low boiling

Endpoint summary

Additional information

Alchisor TAL 123 can be characterised according to three constituents: Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), undecan-1-ol and dodecan-1-ol. Study data, where available, for each constituents has been evaluated and considered together, except for the short-term toxicity to aquatic invertebrates endpoint, where Alchisor TAL 123 is used. In a protective approach the most sensitive study result from across the three constituents has been identified and used to address the endpoint in question. The Key study for each endpoint, which is the most sensitive study result from across the three Alchisor TAL 123 constituents, is summarized below. There was no reliable toxicity data for aquatic plants therefore a waiver is applied for that endpoint. 

 

Short-term Toxicity to Fish

The short-term toxicity in fish of constituents of Alchisor TAL 123 has been documented within this dossier. Adequate reliable measured data exists for short-term toxicity to fish of constituents of Alchisor TAL 123 (namely, Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecan-1-ol and dodecan-1-ol). The most sensitive study result across the three Alchisor TAL123 constituents for this endpoint has been identified in a reliable study with dodecan-1-ol (Veith et al., 1983) which reports an LC50 for short term toxicity in fish of 1.01mg/L. Consequently following the protective approach outlined above this value will be taken as the short-term toxicity in fish endpoint for Alchisor TAL 123.

 

Long-term Toxicity to Fish

Reliable (Klimisch 2) predicted data for Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) exists (Redman, 2010) and provides an estimated NOELR of 0.079 mg/L. Consequently following the protective approach as defined above this value will be taken as the long-term toxicity in fish endpoint for Alchisor TAL 123. Long-term testing with undecan-1-ol or dodecan-1-ol was deemed not necessary and has been waived.

 

Short-term Toxicity to Invertebrates

The short-term toxicity in invertebrates of Alchisor TAL 123 has been evaluated using experimental studies. Alchisor TAL 123 is of low water solubility and test solutions were prepared according to OECD water accommodated fractions (WAF) procedure to assess toxicity due to water soluble components of the test substance, yielding loading rates in lieu of concentrations. While loading rate studies can be used for classification they cannot, however, be used for PNEC derivation (REACH endpoint guidance, chapter 7b); therefore, the substance has been further evaluated using adequate reliable measured data for short-term toxicity to invertebrates for three constituents of TAL 123: Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecanol and dodecan-1 -ol. In a protective approach the most sensitive study result from across the three constituents has been identified and used to address the hazard endpoint in question. The most sensitive measured study result from across the three substances has been identified as a reliable study with dodecan-1 -ol (Laboratory of Pharmacology and Toxicology, 1997) which reports an EC50 for short-term toxicity in aquatic invertebrates of 0.765 mg/L. Consequently this value will be taken as the short-term toxicity in aquatic invertebrates endpoint for Alchisor TAL 123.

 

Long-term Toxicity to Invertebrates

The long-term toxicity to invertebrates of constituents of Alchisor TAL 123 has been documented within this dossier. Adequate reliable measured data exists for long-term toxicity to invertebrates to constituents of Alchisor TAL 123 (namely, Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) and dodecan-1 -ol). Reliable predicted data for the long-term toxicity to invertebrates to undecan-1-ol was also available. The most sensitive study result across the three Alchisor TAL 123 components for this endpoint has been identified in a reliable study with dodecan-1-ol (Schaefers, 2005) which reports a NOEC for long-term toxicity to aquatic invertebrates of 0.014 mg/L. Consequently, following the protective approach as defined above, this value will be taken as the long-term toxicity to aquatic invertebrate’s endpoint for Alchisor TAL 123.

 

Toxicity to Aquatic Algae

The toxicity to aquatic algae of Alchisor TAL 123 has been evaluated using experimental studies. Alchisor TAL 123 is of low water solubility and test solutions were prepared according to OECD water accommodated fractions (WAF) procedure to assess toxicity due to water soluble components of the test substance, yielding loading rates in lieu of concentrations. While loading rate studies can be used for classification they cannot, however, be used for PNEC derivation (REACH endpoint guidance, chapter 7b); therefore, the substance has been further evaluated using adequate reliable measured data for toxicity to algae for three constituents of Alchisor TAL 123 (namely, Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecan-1 -ol and dodecan-1 -ol). The most sensitive study result across the three Alchisor TAL 123 components for this endpoint has been identified in a reliable study with dodecan-1-ol (Huls 1997) which reports a nominal 72-hr NOEC based on growth of 0.085mg/L. Following the protective approach as defined above this value will be taken as the toxicity in aquatic algae endpoint for Alchisor TAL 123.

 

Toxicity to Microorganisms

The most sensitive study result from across the constituents has been identified as a reliable predicted study with Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%). CONCAWE (2010) provided predicted results of a 48-hr NOELR of 1.12 mg/L based on growth inhibition. As documented in this dossier, it is not expected that microorganisms will be exposed to undecan-1-ol and dodecan-1-ol during sewage treatment processes. The need for further testing is waived based on the evidence ofpredicted ready biodegradability at test concentrations in the range that can be expected in the influent to a sewage treatment plant.Consequently, following the protective approach as defined above, the NOELR value of 1.12 mg/L will be taken as the toxicity microorganisms endpoint for Alchisor TAL 123.

 

Alchisor TAL 123 was characterised according to three constituents: Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecan-1-ol and dodecan-1-ol for the aquatic toxicity endpoints.  In a protective approach, the most sensitive study result from across the three constituents was identified and used to address the hazard endpoint in question. Since the most sensitive study result across the three Alchisor TAL 123 constituents was used to represent the toxicity of Alchisor TAL 123, it is deemed that the this approach would be protective of the environment.

The WAF Procedure

A complex UVCB substance such as Alchisor TAL 123 is a mixture 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 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.

Summary of Constituent/Constituent Category and Read-Across Approach

The chemical substances Alchisor TAL 123 and Alchisor TAL 145 were registered according to Article 10 of the REACH Regulation prior to December 2010. Both substances are currently manufactured or imported in quantities exceeding 1,000 tonnes per annum per manufacturer or importer and, as such, the data requirements of Annexes VII to X apply. The Read-Across Justification Document (Section 13) provides supporting information for the registration of Alchisor TAL 123 and Alchisor TAL 145, in particular justification of read-across argumentations, through:

• explanation of the chemical composition of the substances and setting out the justification for use of read-across to its primary constituents, i.e. two well defined analogue substances and one category of substances; and

• justification for use of Alchisor TAL 123 as a source for read across to Alchisor Tal 145 (target). The read-across approach for the Alchisor TAL 123 and Alchisor TAL 145 REACH Registration dossiers includes the following elements:

• Read-across from the constituents of Alchisor TAL 123, as elaborated in Table 1, to Alchisor TAL 123 itself;

• Read-across from the constituents of Alchisor TAL 145, as elaborated in Table 2, to Alchisor TAL 145 itself;

• Read-across from Alchisor TAL 123 to Alchisor TAL 145. From a comparison of the physico-chemical properties, environmental fate and (eco)toxicological endpoints, the following concluding statements can be made:

• The constituents of Alchisor TAL 123 and Alchisor TAL 145 are structurally similar. Alchisor TAL 123 and 145 are predominantly comprised of Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, 2-25% aromatics. Data for other main constituent substances of Alchisor TAL 123 and Alchisor TAL 145, in both cases residual alcohol of a defined chain length, have also been used to develop a complete and reliable data set for Alchisor TAL 123 and TAL 145. Together these constituents account for 95% (w/w) of the composition of Alchisor TAL 123 and TAL 145;

• Physico-chemical properties for Alchisor TAL 123 and TAL 145 are in good agreement with each other, particularly in relation to composition, melting point, boiling point, relative density, solubility, partition coefficient and ignition temperature. The substances both have low solubility in water;

• Recently conducted Alchisor TAL 123 studies provide evidence that the use of the many-to-one read-across approach used to fill data endpoints for Alchisor TAL 123 is both protective and technically valid:

o The constituent/constituent category approach was compared with existing biodegradation data for Alchisor TAL 123 and it was concluded that Alchisor TAL 123 (and TAL 145) and their constituents are not considered to be persistent in the environment, as they are readily biodegradable;

o The constituent/constituent category approach for environmental hazards was compared with new experimental ecotoxicological for an acute aquatic invertebrate and algal exposure using Alchisor TAL 123 and concluded that Alchisor TAL 123 is less toxic than its constituents when tested individually.

o The constituent/constituent category approach for human health hazards was compared with new experimental toxicological for acute oral and 28 -Day repeated dose exposures using Alchisor TAL 123. Results of these studies for Alchisor TAL 123 were generally consistent with observations for the constituents when tested individually, thus strengthening the read-across argument.

• Alchisor TAL 123 and TAL 145 are not considered to be PBT substances; and

• Alchisor TAL 123 and TAL 145 are not classified for environmental hazards under DSD.

• Alchisor TAL 123 is classified Chronic Category 2, and Alchisor TAL 145 is classified as Chronic Category 1 for environmental hazards under GHS classification and labeling regulations.