(1α,2β,4β,6α)-2,2,7-trimethyl-3-oxatricyclo[4.1.1.02,4]octane

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

No biodegradation studies are available for alpha pinene epoxide dextro and no standard biodegradation studies are available for alpha pinene epoxide laevo. However, in a non-guideline study, batch-fed Pseudomonas fluorescens very rapidly (within 5 hrs) degraded (>60%) L-pinene alpha epoxide [removal of the epoxide group at least] under aerobic conditions. In another non-guideline study, by the same investigators, all of a 1.2 g/L dose of L-alpha pinene oxide was degraded within 20 minutes when added to a cell suspension of P. fluorescens under low oxygen conditions (Zorn et al. 2004). The main metabolite in these studies was isonovalal (Zorn et al. 2004). Comprehensive literature searches identified no relevant data on this metabolite. However, isonovalal was predicted to be readily biodegradable using the BIOWIN (V4.10) programme from EPI Suite (US EPA, 2011). As this species of microorganism is fairly ubiquitous in nature, it is reasonable to assume that alpha pinene epoxide laevo (and its main metabolite) and alpha pinene epoxide dextro would rapidly biodegrade in the environment and thus would not be persistent. Indeed, the tested substance in the Zorn et al. (2004) studies would likely contain some of the dextro quality. It is also worthy to note that both alpha- and beta-pinene are readily biodegradable.

No standard bioaccumulation data were identified. However, the predicted Log Kow value for alpha pinene epoxide dextro is below the PBT and vPvB assessment B-screening criterion, which is a log Kow greater than 4.5 (see ECHA guidance table R.11 -2 and Section R.11.1.3.2). Therefore, the substance is considered as not B and not vB.

No studies on toxicity to aquatic organisms were identified for alpha pinene epoxide dextro (or the laevo quality). Relevant studies on mammalian toxicity to assess evidence of CMR and chronic toxicity are also not available. Therefore, the T assessment can not be conducted. However, this assessment is not necessary for the purposes of the PBT assessment, since the substance has been screened as not (v)P and not (v)B.

Based on the above information, alpha pinene epoxide dextro should not be considered PBT or vPvB.

Likely routes of exposure:

Alpha pinene epoxide dextro is an isolated intermediate, the whole life cycle of which is maintained under strictly controlled conditions. As such, no exposure of the environment is expected.