Ethene, homopolymer, oxidized, hydrolyzed, distn. residues, from C16-18 alcs. manuf.

Endpoint summary

Additional information

Ziegler Bottoms are characterized as comprising of two primary constituents; icosan-1-ol and docosan-1-ol. Together these constituents represent a structural class of components (alcohols) that constitute approximately 82% of the composition of Ziegler Bottoms. Study data, where available, for each of these primary constituents has been evaluated and considered together. In a conservative approach the most sensitive study result from across the two 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 two Ziegler Bottoms 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 components of Ziegler Bottoms has been documented within this dossier. Adequate reliable measured data exists for short-term toxicity to fish to components of Ziegler Bottoms (namely, icosan-1-ol and docosan-1-ol). In a conservative approach the most sensitive study result from across the two constituents has been identified and used to address the hazard endpoint in question. The most sensitive study result from across the two substances has been identified as a reliable study with octadecan-1-ol (Wetton 1996), with read-across applied to icosan-1-ol, which reports an LC50for short term toxicity in fish of >0.0011 mg/L, which is at the limit of solubility. Consequently this value will be taken as the short-term toxicity in fish endpoint for Ziegler Bottoms.

Long-term Toxicity to Fish

In accordance with REACH Annex XI, section 1, testing does not appear scientifically necessary for Annex endpoint 9.1.6. Sufficient information is available to predict an absence of toxicity at the limit of solubility for linear alcohols with carbon chain lengths ¿C15. Moreover, from experience gained in tests that have been conducted with substances in this category, considerable technical difficulties would be expected in the conduct of such a test, due to the very rapid biotic removal of the substance from the test system. Therefore, long-term toxicity to fish requirements are waived based on technical testing difficulties, ready biodegradation and low to no short-term toxicity to aquatic organisms at the limit of solubility. No reliable measured or predicted long-term toxicity data to fish for constituents of Ziegler Bottoms is available.

Short-term Toxicity to Invertebrates

The short-term toxicity in invertebrates of components of Ziegler Bottoms has been documented within this dossier. In a conservative approach the most sensitive study result from across the two constituents has been identified and used to address the hazard endpoint in question. The most sensitive study result from across the two substances has been identified as a reliable study with docosan-1-ol (Fisk et al., 2009) where the 96 hr LC50 was predicted at >100 mg/L. However, the predicted LC50 is greater than the limit of solubility (>LoS, which is 0.1 mg/L). It is concluded that under circumstances when the predicted LC50 is greater than the LoS, the substance is not considered to be toxic.

Long-term Toxicity to Invertebrates

In accordance with REACH Annex XI, section 1, testing does not appear scientifically necessary for Annex endpoint 9.1.5. Sufficient information is available to predict an absence of toxicity at the limit of solubility for linear alcohols with carbon chain lengths ¿C15. Moreover, from experience gained in tests that have been conducted with substances in this category, considerable technical difficulties would be expected in the conduct of such a test, due to the very rapid biotic removal of the substance from the test system. Therefore, long-term toxicity to invertebrate requirements are waived based on technical testing difficulties, ready biodegradation and low to no short-term toxicity to aquatic organisms at the limit of solubility. No reliable measured or predicted long-term toxicity data to fish for constituents of Ziegler Bottoms is available.

Toxicity to Aquatic Algae

The toxicity to algae of components of Ziegler Bottoms has been documented within this dossier. Adequate reliable predicted data exists for toxicity to algae to components of Ziegler Bottoms (namely, icosan-1-ol and docosan-1-ol). In a conservative approach the most sensitive study result from across the two constituents has been identified and used to address the hazard endpoint in question. Both constituents are considered non-toxic at the limit of solubility. Therefore, the value used as key in the assessment is the EC50 of >0.001 mg/L which is at the limit of solubility for both docosan-1-ol and icosan-1-ol. 

Toxicity to Microorganisms

Ziegler Bottoms are characterized as comprising of two primary constituents; icosan-1-ol and docosan-1-ol. Together these primary constituents represent a structural class of components (alcohols) that constitute approximately 82% of the composition of Ziegler Bottoms. Study data, where available, for each of these primary constituents has been evaluated and considered together. In a conservative approach the most sensitive study result from across the two constituents has been identified and used to adequately address the Ziegler Bottoms endpoint in question. 

In accordance with Column 2 of REACH Annex VIII, the activated sludge respiration inhibition study (required in Section 9.1.4) does not need to be conducted as the substance is readily biodegradable and the applied test concentrations are in the range that can be expected in the influent to a sewage treatment plant. 

Since the most sensitive study result across the two Ziegler Bottoms constituents was used to represent the toxicity of Ziegler Bottoms, it is deemed that this approach would be protective of the environment.