2-pentylcyclopentan-1-one

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

13 µg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.13 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

1.3 µg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

2.57 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.613 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.061 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.115 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

45.5 mg/kg food

Assessment factor:

300

Additional information

Aquatic toxicity:

To assess the aquatic toxicity of the registered substance, 2 -pentylcyclopentan-1-one, three valid acute studies based on international guidelines are available for the three aquatic trophic levels (algae, aquatic invertebrate and fish) on a read-across substance, 2 -pentylcyclopentan-1-ol, which has the same mode of action and very similar solubility, log Kow and vapour pressure to the reference substance.

Among all data available, a toxic effect was observed for the three aquatic trophic levels and these all occurred at similar levels. The fish Brachydanio rerio (now Danio rerio) is the most sensitive species with a 96h-LC50 at 13 mg/L. For the algae Pseudokirchneriella subcapitata, the 72h-ErC50 was determined to be 14 mg/L, and for the aquatic invertebrates Daphnia magna, the 48h-EC50 was determined to be 18 mg/L.

Both compounds (the registered substance and the read-across substance) are structurally related, in that each has an alkyl chain with five carbon (pentyl) with a cyclopentane ring. Both compounds contain a 2 -pentylcyclopentane skeleton. The cyclopentane ring is associated with a ketone functional group for the registered substance and with an alcohol functional group for the read-across substance. This supporting substance is considered adequate for read-across purposes based on structural similarity, on similar basic physico-chemical properties and similar environmental profile, as well as the same mode of action (MOA 1), between the registered substance and the analogue material used. Indeed, physico-chemical properties directly govern the toxicity of MOA 1 substances. If basic physico-chemical properties are very similar, the toxicity will also be because MOA 1 substances are on the same regression, governed by the solubility. In addition, as the log Kow value of the analogue material is slightly greater than the registered substance, the read-across approach is considered as a worst case scenario (see IUCLID section 13 for justification).

Sediment, terrestrial toxicity and hazard for predators

In the absence of any ecotoxicological data for sediment-dwelling/soil organisms, the PNECs sediment and soil were calculated using the Equilibrium Partitioning Method (EPM). Furthermore, no toxicity studies reporting the secondary poisoning effects on bird were available, therefore the combined 28 -day repeated dose toxicity study performed on the read-across substance was used to derive the PNECoral.

Environmental fate and pathways:

The registered substance is readily biodegradable (76% biodegradation after 28d and satisfied the 10 -d window validation criterion in an OECD Guideline 310 study), therefore it's considered not persistent. In addition, the registered substance has a medium mobility in soils (according to P.J. McCall et al., 1980) with a predicted Koc value at 435.3 L/kg (log Koc = 2.64) and is not considered to be bioaccumulative according to PBT criteria (log Kow < 4.5).

Conclusion on classification

No harmonised classification is available on the registered substance.

10 < lowest E(L)C50 value < 100 mg/L; EC10 or NOEC algae > 1 mg/L; readily biodegradable; log Kow = 3.28.

Classification according to the Annex VI of the Regulation (EC) No 1272/2008 (CLP): The registered substance is not classified for the environment.