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. 

A key reliable (Klimisch 2) Ames study was conducted with docosan-1-ol in S. typhimurium strains TA 98, TA100, TA1535, TA1537 and TA 1538. This study was conducted following a protocol similar to OECD 471 but with some deviations (e.g. No TA102 or E. coli WP2 uvrA; 2-aminoanthracene only positive control with metabolic activation). This study reported that docosan1-ol was negative in this bacterial mutation assay. Study data from this study was used as read-across data to support the equivalent icosan-1-ol endpoint.

A second key study reported on a reliable (Klimisch 2) in vitro mammalian chromosome aberration test conducted with a protocol very similar to OECD guideline 473 with docoasn-1-ol. Docosan-1-ol did not increase the incidence of chromosome aberrations in Chinese hamster V79 cells in the presence or absence of metabolising fraction at concentrations up to 20 µg/ml. There was no evidence of cytotoxicity at this dose level.Study data from this study was used as read-across data to support the equivalent icosan-1-ol endpoint.

In a reliable (Klimisch 2) micronucleus assay conducted according to a procotol similar to OECD 474 the in vivo mutagenicity of docosan-1-ol was assessed. In this study docosan-1-ol did not increase the incidence of micronuclei in mouse bone marrow cells after a single oral gavage dose of up to 500 mg/kg bw. Consequently docosan-1-ol was reported to be negative in this assay. Study data from this study was used as read-across data to support the equivalent icosan-1-ol endpoint.

On the basis of the genetic toxicity information included as part of this submission and in line with the read-across justification included, Ziegler Bottoms are considered not to be genotoxic.

Short description of key information:
In vitro:
Gene mutation (Bacterial reverse mutation assay / Ames test): Docosan-1-ol was negative with and without activation in S. typhimurium strains TA 98, TA100, TA1535, TA1537 and TA 1538 (OECD TG 471)
Cytogenicity in mammalian cells: Docosan-1-ol was negative with and without activation in Chinese hamster ovary cells (similar to OECD TG 473)
Mutagenicity in mammalian cells: Docosan-1-ol was negative with and without activation in Chinese hamster lung V79 cells (similar to OECD TG 476)

In vivo:
Mouse micronucleus study: Docosan-1-ol was negative in bone marrow (similar to OECD TG 474)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

These findings do not warrant the classification of Ziegler Bottoms as genotoxic under the new Regulation (EC) 1272/2008 on classification, labelling and packaging of substances and mixtures (CLP) and under the Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.