Cumene

Endpoint summary

Additional information

Information on effects of cumene on terrestrial organisms are available from a plant growth inhibition test with three plant species and a publication on effects of cumene applied via food to birds.

In the 21 d OECD 208 plant growth test with Sorghum bicolor, Helianthus annuus, Phaseolus aureus toxicity was not detected even at the highest concentration of 1000 mg/kg. Results can be summarised by expressing both toxicity parameters, 21 d EC50 and NOEC as higher than 1000 mg/kg soil.

In the bird study on acute toxicity cumene was applied via food over a test period of 18 hours. The LC50 was found to be > 98.0 mg/kg body weight estimated from the food consumption. The data are imported from IUCLID4 and is therefore assumed to be reliable. Basic data given in the publication, however, no guideline is mentioned and the number of birds is not reported. However, the information is assumed to be sufficient and no further experiments with animals are considered to be necessary

 

Calculation of PNECsoil

Following the "Guidance on information requirements and chemical safety assessment, Chapter R.10: Characterisation of dose [concentration]-response for environment" (ECHA, May 2008), section R.10.6: If no hazard information is available for the soil compartment, the equilibrium partitioning method can be applied to aquatic data to identify a PNEC for soil organisms.

Three situations can be distinguished for deriving a PNECsoil:

• when no toxicity data are available for soil organisms, the equilibrium partitioning method is applied to identify a potential risk to soil organisms. This method is regarded as a “screening approach”.

• when toxicity data are available for a producer, a consumer and/or a decomposer the PNECsoil is calculated using assessment factors.

• when only one test result with soil dwelling organisms is available the risk assessment is

performed both on the basis of this result using assessment factors and on the basis of the

equilibrium partition method (EPM). From both PECsoil/PNECsoil ratios the highest one is

chosen for the risk characterisation.

 

For cumene, only test results for a producer are available and test results with soil dwelling organism are not available. Concerning soil dwelling organisms, the data base is equivalent to the above described situation "no toxicity data available" and the PNECsoil is calculated using the equilibrium partitioning method to identify a potential risk to soil dwelling organisms.

PNECsoil derivation from the equilibrium partitioning method: 0.347 mg cumene/kg soil wet weight

 

PNECsoil derivation from the plant toxicity test using assessment factors:

The reported EC50 value of > 1000 mg/kg soil corresponds to the highest test concentration showing no effect and the use of the assessment factor of 1000 is not appropriate. The PNECsoil can be calculated applying a factor of 100 to the 21 day NOEC of ≥ 1000 mg/kg soil:

PNECsoil= 1000 mg cumene/kg soil / 100 = 10 mg cumene/kg soil.

 

Due to the low sensitivity of plants the PNECsoil calculated using the equilibrium partitioning method will become the essential instrument in the risk characterisation of cumene for soil organism.