9-Octadecenoic acid (Z)-, monoester with 1,2,3-propanetriol ester with boric acid (H3BO3)

Endpoint summary

Key value for chemical safety assessment

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

10

Absorption rate - inhalation (%):

100

Additional information

Introduction

No experimental studies of the absorption, metabolism, distribution, or elimination of 9-Octadecenoic acid (Z) -, monoester with 1,2,3-propanetriol ester with boric acid in mammals are available. However, information is utilized from the physical chemical properties and the existing toxicology studies to infer as far as possible, the potential toxicokinetics of the substance.

Physicochemical properties

The substance 9-Octadecenoic acid (Z) -, monoester with 1,2,3-propanetriol ester with boric acid is an organic substance of Unknown or Variable composition, Complex reaction product (UVCB substance). It is a yellow liquid at 20 °C and has a molecular weight of 442.39 g/mol. It is moderately water soluble (water solubility approximately 10 mg/L, determined using an optical turbidity measurement) with a log Pow value of 4.4 at 25°C. The substance was considered as readily biodegradable, as evidence of >70% degradation was shown over a 28-day period in a standard biodegradation study.

Absorption

Oral absorption

The relatively high molecular weight, together with the moderate water solubility and high log Pow would indicate a moderate oral absorption. In the available acute oral toxicity studies, treatment at 5000 mg/kg bw did not produce any mortality, or clinical signs, or effects on body weight. In the absence of any quantitative data, oral absorption is assumed at a default of 50% for risk assessment purposes.

Dermal absorption

Although the physical state (liquid) is more favourable for dermal absorption, the high molecular weight, high log Pow value and moderate water solubility suggest that dermal absorption would be low to moderate. This is supported by results of a 28-day dermal toxicity study in rats, where only minimal local effects but no systemic effects were observed at the limit dose of 1000 mg/kg bw/day (Duke, Cisson & Wong, 1982). As the molecular weight is very close to 500 g/mol and the Log Pow is greater than 4, 10% dermal absorption is assumed for risk assessment purposes.

Inhalation absorption

In the absence of any quantitative data, absorption of the compound following inhalation is assumed to be 100%.

Distribution

No information is available to describe the distribution of the substance following dermal absorption. As under hydrolytic conditions, including aqueous environments, it is expected that the borated ester will quickly (<30 seconds) convert to boric acid (CAS RN 10043-35-3) and glycerol monooleate (CASRN 25496-72-4), which can be further converted to yield glycerol (CASRN 56-81-5) and 9Z-octadecenoic acid (CASRN 112-80-1), following oral administration the fatty acids will be will be distributed via chylomicrons and/or lipoproteins to reach tissues and organs.

Metabolism

The generated fatty acids are expected to be used a source of energy by the cells. Elimination Boric acid will be promptly excreted via the urine. Since the boron component might be expected to be rapidly eliminated, and glycerol and fatty acids extensively metabolised, bioaccumulation is not predicted.

Conclusion

For risk assessment purposes, oral absorption is assumed at 50%, dermal absorption at 10% and absorption following inhalation at 100%.