Registration Dossier

Environmental fate & pathways

Endpoint summary

Currently viewing:

Administrative data

Description of key information

Additional information

The Rosin adducts and rosin adduct salts category is a UVCB category and includes rosin or rosin salts that have been chemically reacted with either fumaric acid or maleic anhydride, including:

- Rosin, maleated

- Rosin, fumarated

- Resin acids and rosin acids, maleated calcium salts

- Resin acids and rosin acids, maleated sodium salt.

 

Resin acids are the predominant components of rosin (>85%). Resin acids are composed of three skeletal classes of tricyclic carboxylic acids which share similar structures, but vary in the position of the double bonds and methyl groups.

 

As substances in this category are UVCBs, the proportion of the different resin acids will vary between substances and between samples of the same substance. However, biodegradation potential of different resin acids is similar and therefore this variation is not considered to affect biodegradation potential. The presence of a metal cation will not alter the structure of the organic component of the molecule, and therefore will not impact on the biodegradation potential. Although differences in ecotoxicity have been observed between maleated and fumarated substances within the category, the structural differences between maleated and fumarated category members are not considered to affect biodegradation potential and it is considered to be appropriate to read across biodegradation data between all members of the category.

 

Biodegradation data are available for both maleated and fumarated members of the category and results from all studies indicate that the substances are not readily biodegradable. The similarity of results between maleated and fumarated substances supports the use of read across between category members for this endpoint.

 

Bioaccumulation studies have not been conducted for any category member due to the analytical difficulties with conducting such a study with UVCB substances containing constituents with differing, and often low, solubility. However, literature data are available for individual resin acids. Rosin, the starting material for preparing rosin adduct substances, is made up of resin acids and therefore data on the individual resin acids provides an indication of the bioaccumulation potential of rosin adduct substances. Resin acids have been shown not to bioaccumulate and it is therefore considered likely that rosin adduct substances will also not bioaccumulate.

 

A hydrolysis study has not been conducted for any category member. Conducting a hydrolysis study would be incredibly challenging analytically due to the nature of the substances as they contain many constituents, many of which are poorly soluble.

 

Due to the UVCB nature of the substances, adsorption / desorption is also difficult to assess experimentally. However, calculated Koc values have been determined for category members and these range from log Koc 1.315 – 6.256. The range in values is considered to be due to different constituents within the UVCB having different adsorption potential.