3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-3-en-2-one

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.002 mg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.019 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0 mg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

1 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.067 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.007 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:

0.053 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

33.3 mg/kg food

Assessment factor:

300

Additional information

An appropriate structural analogue (3-methyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol, tradename Ebanol) was used as read-across to address the data requirements for the aquatic toxicity of MTCP Crude. Short-term aquatic toxicity data are available for each of the three freshwater trophic levels (fish, Daphnia and algae) for ebanol. The observed L(E)C50 values are:

96-hour LC50 for freshwater fish fathead minnow (Pimephales promelas) = 2.3mg/l

48-hour EC50 for freshwater invertebrate Daphnia magna = 1.9mg/l

72-hour growth rate EC50 (ECr50) for freshwater algae Pseudokirchneriella subcapitata = 24mg/l

The toxicity to STP microorganisms has been assessed using the activated sludge respiration test. The observed 3-hour EC50 and EC10 were 52.5mg/l and 10.0mg/l respectively.

The aquatic toxicity data of the target substance (MTCP Crude) and source substance (Ebanol) are anticipated to be similar because they are expected to exhibit the same mode of action, non-polar narcosis, and have similar physical-chemical properties (see read-across justification document in section 13 for more details).

In the absence of toxicity data for soil organisms, the PNECsoil has been calculated from the PNECwater using the Equilibrium Partitioning Method (EPM) and incorporated into the CSA to assess indirect exposure to soil organisms.

Conclusion on classification

Environmental classification and labelling of a substance is generally based on data from short-term aquatic toxicity results, the ready biodegradability of the substance and the measured octanol/water partition coefficient.

 

The estimated log Kow for MTCP crude is 4.42 to 4.84 using the calculation software KOWWIN v. 1.68 (EPISuite v 4.1). MTCP crude is expected to be readily biodegradable and to have a lowest acute L(E)C50 value in the range of >1 to ≤ 10 mg/L, based on read-across from the structurally related analogue, Ebanol.

 

Based on the above information, MTCP Crude is considered to be classified as R51/53 according to Directive 67/548/EEC (DSD) and Aquatic Chronic 2 (H411) according to Regulation 1272/2008/EC (CLP). The read-across substance, Ebanol, has the same environmental classification.