Resin acids and Rosin acids, calcium zinc salts

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

The category rosin, hydrogenated rosin and their salts contains rosin and monovalent and divalent salts of rosin, as well as hydrogenated variants of these. Rosin and rosin salts are UVCB substances and the main constituents for all category members are resin acids. Oligomers of resin acids (mainly dimers) can also be present in rosin and rosin salts substances.

Ready biodegradation studies are available for a number of different category members, covering rosin, monovalent and divalent salts of rosin and hydrogenated variants. Although there is some variation in the amount of degradation demonstrated in these studies, likely to be due to the low solubility of the test items and difficulties with ensuring bioavailability of the test item, the weight of evidence demonstrates that substances in this category are readily biodegradable and therefore not persistent or very persistent. An enhanced ready biodegradation study and an inherent biodegradation study are also available for category members, and also indicate that these substances are unlikely to be persistent. Based on measured biodegradation data, substances in the category rosin, hydrogenated rosin and their salts are not considered to be persistent.

Measured BCF values are available for nine resin acids, with values ranging from 23 to 129. Resin acids are the main constituents in rosin and rosin salts, and these BCF values are far below the bioaccumulation threshold, therefore rosin and rosin salts are not considered to be bioaccumulative. In addition, QSAR predictions have been conducted for a representative structure of rosin dimers and based on the predictions these constituents are considered to have a low potential for bioaccumulation due to their large molecular size and very high log Kow (log Kow >10), meaning that they are unlikely to be taken up by organisms. Overall, members of the category rosin and rosin salts are not considered to be bioaccumulative.

Acute ecotoxicity results are available for members of the rosin and rosin salts category, covering rosin, monovalent and divalent salts of rosin and hydrogenated variants. The lowest LC50 value is 1.6 mg/L forDaphnia magna(Eastman 2005), for category member resin acids and rosin acids, hydrogenated, potassium salts. Members of this category have not been classified as Carcinogenic Cat 1A or 1B, mutagenic Cat 1A or 1B, Toxic to reproduction cat 1A, 1B or 2 or STOT-RE cat 1, Cat 2. Based on the toxicity data available for category members, members of the category rosin and rosin salts are not considered to be toxic.

PACT assessments were conducted by the Finnish competent authority for category members rosin, rosin, hydrogenated and resin acids and rosin acids, sodium salts (Tukes 2015). The assessments state that the conclusions can, in principle, be applied to all members of the category. Tukes based their assessment on the available measured data and EPISuite predictions conducted based on abietic, isopimaric and neoabietic acids, as representative structures. The assessments conclude that “the substance is not considered to meet the PBT/vPvB criteria based on the available, mainly screening level, information. This conclusion covers the relevant constituents.”

Overall, members of the category rosin, hydrogenated rosin and their salts are not considered to be PBT or vPvB.