Resin acids and Rosin acids, fumarated, compds. with triethanolamine

Endpoint summary

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

10

Absorption rate - inhalation (%):

10

Additional information

General

There were no studies available where the toxicokinetic behavior of resin acids and rosin acids, fumarated, compds. with triethanolamine was evaluated.

Resin acids and rosin acids, fumarated, compds. with triethanolamine is an orange, amber solid, with a molecular weight of about 532 g/mol (ranging from 302.5 – 1118.6 g/mol). The substance exhibits a water solubility of <1 mg/L and the partition coefficient logPo/w was estimated to be of > 5.875. The vapor pressure was calculated to be between 2.04 and 15.4 Pa.

The substance is a reaction product of rosin with fumaric acid and triethanolamine (CAS 102-71-6) resulting in esters of rosin, fumarated (CAS 65997-04-8). Since rosin, fumarated is a derivate of the UVCB rosin consisting of gum rosin, wood rosin and tall oil rosin, the substance resin acids and rosin acids, fumarated, compds. with triethanolamine is also a UVCB. Therefore, various components will attribute to the overall substance properties.

Components of Resin acids and Rosin acids, fumarated, compds. with triethanolamine(Average MW 532)

	Rosin acid	Rosin acid fumarated	Mono-Ester	Di-Ester	Tri-Ester
Mw	302	418	434	834	1119
%	52	6	8	23	11
logPow	3.1-6.2*	2.8
WS mg/L	0.9	9

*         Value at neutral pH, at pH 2 main peaks at 5.8 and 6.4

Toxicokinetics

Oral

In general, molecular weight < 500 is favorable for absorption by the gastrointestinal tract (GI). For substances with logPow >4 and low water solubility (< 1 mg/L) uptake via the GI tract is in general low, but some micellular solubilisation by bile salts in the gastro-intestinal tract may allow crossing of lipid biomembranes.

Based on molecular weight and logPow (where available) oral absorption of the components rosin acid, the di-ester and the tri-ester is expected to be very low.

Rosin acid fumarated is expected to be absorbed easily in view of its molecular weight and logPow. In addition, the molecular weight of the mono-ester may be favorable for absorption.

The low pH of the stomach is likely to initiate hydrolysis of the ester bonds inResin acids and Rosin acids, fumarated, compds. with triethanolamine. In addition, gastric esterases are expected to contribute to this process. The hydrolysis products of the esters, i.e. rosin acids fumarated and triethanol amine (TEA) are well absorbed, TEA 63% (data from IARC) and rosin fumarated 100% (default value, see above). When hydrolysis would be complete, 100% absorption by default of 48% of the components as indicated above could be expected. The main absorbed component is expected to be rosin fumarated (in the UVCB the maximum amount of TEA would be 4%).

 

Dermal

As is the case for oral absorption, dermal absorption depends on molecular size, water solubility and logPow. No or very limited hydrolysis in the skin is expected before absorption. With an average molecular size of 532 g/mol and a water solubility below 1 mg/L, the absorption of resin acids and rosin acids, fumarated, compds. with triethanolamine is anticipated to be low (ECHA, 2008). In addition, with the logPow >5.875 (see table 1) the rate of penetration may be limited by the rate of transfer between the stratum corneum and the epidermis.

 

Inhalation

Uptake by inhalation of resin acids and rosin acids, fumarated, compds. with triethanolamine is not expected, as the substance is a solid having a low vapor pressure of 2.04 – 15.4 Pa. Although the substance’s main use is within solution and thus inhalation via aerosols could occur, the uses during the whole life cycle are not expected to lead to release of vapors or mists containing respirable and/or inhalable particles/droplets. Therefore exposure and concomitant uptake via inhalation can be excluded. Based on the logPow and water solubility respiratory absorption is expected to be low (set at 10% as default value). No hydrolysis of the ester components in the test substance is expected.

 

Conclusion

The uptake of resin acids and rosin acids, fumarated, compds. with triethanolamine via the dermal and inhalation route is expected to be limited. A certain amount of hydrolysis is expected after oral exposure. The hydrolysis products rosin acid fumarated and TEA are expected to be rapidly absorbed. The hazard assessment shows low toxicity of either degradation product. TEA (at a maximum present at 4%, the original loading rate) will be excreted unchanged rapidly. Therefore this document will concentrate on the read-across towards rosin acid fumarated.

No hydrolysis of the ester bonds is expected under environmental conditions. Therefore for e-fate and environmental toxicity, read-across to rosin fumarated is only considered in a weight of evidence approach. Aquatic and terrestrial organisms will be exposed to all components. Uptake if any, however, is expected mainly for the components rosin fumarated and the mono ester in view of similar considerations as were expressed under oral uptake.