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Description of key information

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

Oxooil LS9 is a complex mixture (UVBC) of C8 saturated hydrocarbons. The significant water solubility (283 mg/L), moderate molecular weight (112-114) and high n-octanol/water partition coefficient (Log Kow 5.4 to 6.2) indicate that Oxooil LS9 has potential for bioavailability. 

Although there were no systemic signs of reaction to treatment following acute oral exposure in rats (Section 7.2.1), the absorption of Oxooil LS9 via the gastro-intestinal tract, possibly involving the lymphatic system, was clearly demonstrated following subacute administration in this species (Section 7.5.1). The minimal hepatic centrilobular hypertrophy observed in all male and high dose female treated groups indicated a metabolic adaptation to the absorption of Oxooil LS9, and the dose-relate increase in hyaline droplets in the renal cortical tubular cytoplasm of treated male rats indicates that the kidney is likely to be the primary route of excretion of these short chain hydrocarbons and their metabolites. The primary metabolic pathways would probably involve carbon oxidation to give first alcohols and then carboxylic acids. This could occur at the terminal chain carbons, the branch methyl groups, the unsaturated carbon atoms and at more than one carbon to give diols, dicarboxylic acids or combinations of the two. The alcohols and carboxylic acids could be conjugated with glucuronic acid to give hydrophilic metaboiltes that would be readily excreted in humans.

 

Evidence of general distribution to the tissues and organs was revealed in the subacute study by the macroscopically abnormal pink discolouration in the sciatic nerve, adipose tissue, seminal vesicles, prostate and urinary bladder of animals treated at 300 or 1000 mg/kg/day. The pink colour was probably a metabolite of one of the constituents of Oxooil LS9, but its identity is otherwise unknown. There was no toxicological or otherwise visible evidence of distribution to the central nervous system.

 

 The delayed contact hypersensitivity observed in the murine local lymph node assay (Section 7.4.1) shows that absorption of Oxooil LS9 occurs through the skin, although the weakness of the response (EC3, 37%) and the absence of systemic effects following acute dermal exposure (Section 7.2.3) indicate that it may be fairly limited. A degree of absorption would be expected via the lung, although toxicological evidence indicates that it is unlikely to be any greater than by the oral route.