Bis[(2-ethyl-1-oxohexyl)oxy]dioctylstannane

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

no hazard identified

Marine water

Hazard assessment conclusion:

no hazard identified

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

no hazard identified

Sediment (marine water)

Hazard assessment conclusion:

no hazard identified

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Read-across Justification

The target substance bis[(2-ethyl-1-oxohexyl)oxy]dioctylstannane (DOT EHA CAS: 24577-34-2, EC: 246-325-3) is a mono-constituent organotin substance that consists of a tin as central metal element with two octyl-ligands. The source substance dioctyltin oxide (Public name: DOTO, CAS: 870-08-6, EC: 212-791-1) is also an organotin compound and has the identical structure elements as the target substance in respect of the tin-alkyl moiety.

According to WHO IPCS CIRCAD (2006) organotin compounds are characterized by a tin–carbon bond and have the general formula RxSn(L)(4−x), where R is an organic alkyl or aryl group and L is an organic (or sometimes inorganic) ligand. The organotin moiety is significant toxicologically. The anionic ligand influences physicochemical properties but generally has little or no effect on the toxicology.

Since the target substance and the source substances share the identical organotin moiety, and the organotin moiety is generally recognized as the relevant toxophore of organotins and the toxicity estimates (AE) respectively toxicity limits for organotins are expressed as tin, the overall ecotoxicity/systemic toxicity of the target can be interpolated by assessing the (eco-)toxicity of the source (WHO IPCS CIRCAD, 2006, BAUA AGS TRGS 900, 2014, Summer KH, Klein D and Greim H, 2003). As the source has a higher relative amount of tin based on molecular weight (source 32.87%, target 18.80%) the read-across approach to DOTO can be assessed as conservative (worst case).

The purity of the source and target substance are expected to be high, based on the manufacturing method. The impurity profile is not expected to have strong effects on substance properties and any impurity of (eco-)toxicological relevance of the source substances is expected to be present in the target substance. Consequently, the hazard profiles of the source substances, including those of their impurities, are intrinsically covered. Differences in impurities are not expected and thus do not have an impact on the (eco-)toxic properties.

The bioavailability of both substances varies in a predictable manner and is assumed to be dependent on the water solubility. The prediction of the effects of the target substance is based on the relationship between solubility and (eco-)toxicity or on a worst-case basis.

 

References

BAUA (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (Federal Institute for Occupational Safety and Health)) AGS (Ausschuss für Gefahrstoffe (Committee on Hazardous Substances)) TRGS (Technical Rules for Hazardous Substances) 900 (2014). Begründung zu n-Octylzinnverbindungen, April 2014.

Summer KH, Klein D, Griem H (2003). Ecological and toxicological aspects of mono- and disubstituted methyl-, butyl-, octyl-, and dodecyltin compounds - Update 2002. GSF National Research Center for Environment and Health, Neuherberg, for the Organotin Environmental Programme (ORTEP) Association.

World Health Organization (WHO) International Programme on Chemical Safety (IPCS) Concise International Chemical Assessment Document (CICAD) 73 Mono- and disubstituted methyltin, butyltin, and octyltin compounds (2006). Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization, and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals. World Health Organization ISBN 978 92 4 153073.

Conclusion on classification

Short-term toxicity testing on fish: Hooftman & de Wolf (2004), OECD 203 and EU method C.1; LC50>water solubility

Short-term toxicity on invertebrates: Hooftman & de Wolf (2004), OECD 202 and EU method C.2; EC50>water solubility

Growth Inhibition Study on Aquatic Plants: Rufli (1988), OECD 201; ErC50 > water solubility

The substance is not readily biodegradable

In accordance with the criteria outlined in Regulation EC No. 1272/2008 (CLP) and Directive 67/548/EEC (DSD), the substance does not meet the critieria for classification as dangerous to the environment.