2-Propenoic acid, 2-cyano-3-(4-methoxyphenyl)-3-phenyl-, 2-ethylhexyl ester

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0 mg/L

Assessment factor:

50

PNEC freshwater (intermittent releases):

0 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0 mg/L

Assessment factor:

500

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 mg/L

Assessment factor:

10

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.962 mg/kg sediment dw

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.096 mg/kg sediment dw

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.192 mg/kg soil dw

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

66 700 mg/kg food

Assessment factor:

300

Additional information

Reliable test data are available for the three principle trophic levels: primary producers, represented by algae; plant eating animals, represented by daphnids; and predators, represented by fish. In the case of the current chemical, long-term studies are represented by an algal study and by a 21 -day study in Daphnia magna (see Guidance on Information Requirements and Chemical Safety Assessment. Chapter R.10, May 2008). All of these studies represent freshwater species. For the purpose of setting a PNEC value for freshwater aquatic organisms, the most appropriate starting value is the NOEL of 0.0048 mg/L obtained in the study with daphnids. Given that two trophic levels are represented with long-term study results (algae and daphnids), an assessment factor of 50 is applied. Similarly, an assessment factor of 500 is applied to the NOEL from daphnids to obtain the PNEC value for marine aquatic organisms.

Given the lack of a measured LC50 value in an aquatic species, the PNEC vlaue for intermittent releases was set as 1/10 of the NOEC value from the daphnid study.

Based on the NOEC of 1000 mg/L (nominal) from an activated sludge inhibition test, a PNEC STP value of 100 mg/L was determined.

No reliable test data for sediment organisms have been identified for the subject chemical. PNEC values for this environmental compartment are calculated using the Equilibrium Partitioning Method (EPM) that uses both PNEC values for aquatic organisms and estimations of environmental partitioning based on physico-chemical properties. The following equation is recommended for the estimation of a PNEC value for sediment organisms (see Guidance on Information Requirements and Chemical Safety Assessment. Chapter R.10, Section R.10.5.2.1 and Equation R.10-2, May 2008):

 

PNEC_{freshwater sediment}= K_{susp. solids-water}/RHO_{susp solids}x PNEC_freshwaterX 1000

 

Where, K is the partition coefficient for suspended solids and water (units of m³/m³), RHO is the bulk density of wet suspended solids (1150 kg/m³in this case), and PNEC_freshwater is as calculated previously.

The partition coefficient, K, and the PNEC_{freshwater sediment} value wereobtained from the EUSES Program (Ver. 2.1) with the following inputs:

 

Molecular Weight = 391.51 g/mole

Vapor Pressure = 2.0E-05 Pa (at 25 °C)

Water Solubility = 0.04 mg/L

Octanol-Water Partition Coefficient (log, estimated) = 6.05

The EUSES program provided the following values:

 

PNEC_{freshwater sediment}= 0.962 mg/kg of dry wt.

 

PNEC_{marine-water sediment}= 0.0962 mg/kg of dry wt

There are no available terrestrial effects testing results for the subject chemical for any soil-dwelling organism. Based on the safety assessment guidance for this endpoint (Chapter R.7c, R.7.11.5.3), extrapolating aquatic toxicity data using the Equilibrium Partitioning Method is recommended. In the same way as the above PNEC values for sediment were obtained, a PNEC_soil value was calculated using the EUSES program (see Guidance on Information Requirements and Chemical Safety Assessment. Chapter R.10, Section R.10.6.1 and Equation R.10-5, May 2008). The EUSES program gave the following:

 

PNEC_soil= 0.192 mg/kg dry wt.

There is no available information on the long-term or reproductive toxicity of the subject chemical to birds (see REACH, Annex X). However, appropriate information is available from repeated-dose studies in mammalian species. For the calculation of an environmental PNEC_oral value for the subject chemical, an NOAEL value of 1000 mg/kg bwt/day, obtained in a sub-chronic rat oral gavage study (OECD Guideline 422), served as the starting point. This was used to calculate a PNEC_oral value (see Guidance on Information Requirements and Chemical Safety Assessment. Chapter R.10, Section R.10.8.2).

 

A NOEC_rat,food(kg/kg_food) is obtained from the following equation:

 

NOEC_rat,food= NOAEL_ratx CONV_rat

 

(NOAEL_ratin units of kg/kg bwt/d)

 

CONV_rat= 20 (g body wt / g daily food intake)

 

(for rat > 6 weeks of age)

 

Therefore,

 

NOEC_rat,food= 1.0 x 10 ^-3kg/kg bwt/d x 20 = 20 x 10 ^-3 kg/kg_food

An assessment factor of 300 (for the sub-chronic rat study) was applied to this NOEC value to give the final PNEC_oral (see Guidance on Information Requirements and Chemical Safety Assessment. Chapter R.10, Section R.10.8.2 and Table R.10-13).

 

PNEC_oral= 20 x 10 ^-3/ 300 = 0.0667 x 10 ^-3 kg/kg_food

 

or 66,700 mg/kg_food

Conclusion on classification

Based on the lack of a measured acute (LC50/EC50) value for the subject chemical, it is not classifiable for acute aquatic toxicity hazard in accordance with Directive 67/548/EEC and EU CLP (Regulation (EC) No. 1272/2008).

Category 1 is the only classification for acute toxic hazard, aquatic toxicity adopted by the EU CLP (Regulation (EC) No. 1272/2008), and the subject chemical does not meet this criterion for classification. UN GHS adopts additional categories of acute aquatic toxicity. However, these are all based on LC50/EC50 values at or below the water solubility. Therefore, in non-EU countries that adopt UN GHS, the subject chemical would not meet the criteria to be classified as an Acute Aquatic Hazard.

Similarly, the subject chemical is not subject to classification under the EU CLP criterion for Chronic categories 1, 2 or 3, based on the lack of a measured LC50/EC50 value in an aquatic species. Also, given the subject chemical's presumed low potential for bioaccumulation, it is not classified as Chronic Category 4 under the EU CLP criterion or under the UN GHS classification system.