Reaction mass of (3aR*,5aS*,9aS*,9bR*)-3a,6,6,9a-Tetramethyldodecahydronaphtho[2,1-b]furan and (3aR*,5aS*,9aS*,9bS*)-3a,6,6,9a-Tetramethyldodecahydronaphtho[2,1-b]furan

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.027 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

27 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

2.7 µg/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

2.7 µg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

14.27 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

1.43 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:

2.84 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

53.33 mg/kg food

Assessment factor:

300

Additional information

Reliable calculation method results are available to assess the aquatic toxicity of the registered substance, on aquatic invertebrates, algae and fish, for acute and chronic exposure. 

The algorithm is based on a QSAR model which has been validated to be compliant with the OECD recommandations for QSAR modeling (OECD, 2004b, 2007).  The ecotoxicological predictions were determined using iSafeRat® calculation method adapted for a mixture of compounds with the Mechanism of Action (MechoA) in question (MechoA 1.1, i.e.non-polar narcosis). QSAR models are based on validated data for training sets for which the concentrations of the test substance had been determined by chemical analyses over the test period.

No toxic effects were observed up to the attainable limit of solubility of the substance in experimental acute studies for the three trophic levels (fish, aquatic invertebrates and algae). Maximal solubility of the test item in water, is the loading rate of 2.73 mg/L

According to these predictions and the experimental study:

- The acute 48-EL50 value for aquatic invertebrates, based on mobility, was predicted to be >solubility limit 2.73 mg/L ;

- The acute 72h-ErL50 and NOELr value for algae, based on growth rate, was predicted to be > solubility limit = 2.73 mg/L ;

- The acute 96h-LL50 value for fish, based on mortality, was predicted to be > solubility limit = 2.73 mg/L ;

-The chronic 21d-EL10 value for aquatic invertebrates, based on reproduction, was predicted to be 0.23 mg/L 

- The chronic 32d-EL10 value for fish, based on growth or reproduction, was predicted to be 0.46 mg/L 

 

In addition, an experimental acute Daphnia study (NOACK, 2015) is available. In this study, two non GLP range-finding tests were performed on the registered substance according to OECD Guideline 202 and EU Method C.2. The biological effects of the first and the second range-finding tests are consistent at 0.7 mg/L (5% immobilisation) and 1 mg/L (10% immobilisation). Therefore, the 48h-EC50 value is expected to be greater than 1 mg/L based on analytically confirmed nominal concentrations. As this value strongly supports the acute iSafeRat® prediction obtained on aquatic invertebrates, and the substance falls under the definition of "difficult to test" according to OECD guidance No. 23, the definitive study was not considered necessary.

 

One experimental long term toxicity study to aquatic invertebrates is avalaible. - The chronic 21d-EC10 value for aquatic invertebrates, based on reproduction, was determined to be 0.268 mg/L (95% CL: 0.194 - 0.371 mg/L).

Finally, an experimental study is available to assess the toxicity of the registered substance to microorganisms. In this study (Envigo, 2017), performed according to OECD Guideline 209, no statistically significant toxic effects were observed on the respiration of activated sludge microorganisms after a contact time of 3 hours at all of the test concentrations employed (10, 100 and 1000 mg/L). The 3h-EC50 value was determined to be greater than 1000 mg/L and the 3h-NOEC was 1000 mg/L.

 

Environmental fate and pathways

With only 32% biodegradation after 28 days of incubation (OECD Guideline 301D), the registered substance is considered as not readily biodegradable.However, in the prolonged Close Bottle test, the substance was biodegraded by 62% at day 60. This indicated that the registered substance undergoes a biodegradation and should be considered as non-persistent following the EU PBT/vPvB criteria. Regarding hydrolysis potential, the study is technically not feasible based on the poor water solubility of the substance.

The average bioconcentration factor (BCF) of the registered substance determined, by read-across, at 373 L/kg indicate that the substance did not bioaccumulate in the rainbow trout (in vivo OECD Guideline 305 and in vitro biotransformation assay). Finally, the adsorption coefficient (log Koc) of the registered substance determined, by read-across also, at 3.72 (OECD Guideline 121), indicate that the substance is immobile in soil (according to Mc Call et al., 1980).

Conclusion on classification

No harmonised classification is available.

 

Data available:

- not readily biodegradable;

- average BCF value of 373 L/kg on a read-across substance (in vivo OECD Guideline 305 and in vitro biotransformation assay using liver S9 fractions and hepatocytes from rainbow trout)

- acute data:  no acute toxic effects were observed on all trophics levels at or even close to the water solubility of the substance. 

- chronic data:  Chronic effets were observed at 0.268 mg/L for daphnid. 

Classification according to the Annex I of the Regulation (EC) No 1272/2008 (CLP): The test substance is classified as Aquatic Chronic 2 for the environment, based on acute toxicity data and the non ready biodegradability.

 

* Ahlers J, Riedhammer C, Vogliano M, Kühne R-U and Schüürmann G (2006) Acute to Chronic Ratios in Aquatic Toxicity – Variation across Throphic Levels and Relationship with Chemical Structure. Environmental Toxicology and Chemistry 25:2937-45.