Bis(isopropyl)naphthalene

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0 mg/L

Assessment factor:

50

Extrapolation method:

assessment factor

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0 mg/L

Assessment factor:

500

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

0.15 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.853 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.085 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:

0.171 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

25 mg/kg food

Assessment factor:

68

Additional information

PNEC aqua (freshwater)

PNEC derivation following procedures of TGD (R.10):

For diisopropylnaphthalene, short-term toxicity tests have been performed for three trophic levels: fish, invertebrates (Daphnia magna), and green algae (Pseudokirchnerella subcapitata). In older studies, no relevant lethal or inhibitory effects were observed within the water solubility of DIPN. A recent study (Aniol et al 2012) demonstrated that acute toxic effects emerged under closed conditions of the test system with an effect loading EL50 of 1.7 mg/L.

Based on slight effects on the immobilization of daphnia within the water solubility of DIPN (EC0 = 0.066 mg/L), daphnia proved to be the most sensitive species. In tests using solubilising vehicles, daphnia also showed the lowest L/EC50 values.

For DIPN a long-term toxicity study with Daphnia is available (21 d reproduction test according to OECD 211). The determined NOEC was 0.0118 mg/L (meas. TWA). The result is confirmed by a second chronic toxicity study (21 d reproduction and immobilisation study according to OECD TG 202 part 2, adopted 1984) reporting a NOEC of 0.013 mg/L (nominal). In a 72-h growth inhibition test with green algae (Scenedesmus subspicatus), a 72-h NOEC of ca. 0.15 mg/L was determined (highest concentration tested, 80% of a saturated solution/water-accommodated fraction with a measured concentration of 0.19 mg/L).

Derivation of PNEC aqua freshwater can be based on results of long-term tests with organisms of two different trophic levels (Daphnia and algae). A test with the most sensitive species in short-term toxicity tests is included (Daphnia). The PNEC aqua freshwater will be calculated using the NOEC determined in this test (NOEC = 0.0118 mg/L) applying an assessment factor of 50 according to table R.10-4 in TGD "Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment".

 

PNEC aqua (marine water)

PNEC derivation following procedures TGD (R.10):

In addition to tests with freshwater, one study is available using the marine copepod Arcatia tonsa in a semi-static reproduction and mortality test with natural salt water. A NOEC of 0.02 mg/L was determined in this study.

As the long-term NOEC for daphnia is lower (0.0118 mg/L), the derivation of PNEC aqua (marine water) will be based on this value. With regard to a wider diversity of taxonomic groups in saltwater, an assessment factor of 500 will be used to allow for a broader distribution of sensitivities in the marine environment.

 

PNEC STP

In two growth inhibition tests using Pseudomonas putida and Tetrahymena pyriformis as test organisms, no toxicity was observed within the range of water solubility of diisopropylnaphthalene (EC10 > 0.16 mg/L, UBA/KBwS 1999a; EC0 > 0.15 mg/L, Yoshioka 1985). According to chapter R.10.4.2 and table R.10-6 in TGD "Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment", an assessment factor of 1 is applied to NOEC / EC10 values from growth inhibition tests withPseudomonas putida or Tetrahymena pyriformis.

 

PNEC sediment (freshwater)

According to chapter R10.5.2.1 of TGD "Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment",the PNEC sediment can provisionally be calculated in the absence of data for sediment-dwelling organisms using the equilibrium partitioning method (EPM).

PNEC derivation following procedures of TGD (R.10 and R.16):

PNEC water (freshwater): 0.000236 mg/L,

Koc: 36108 (EPA EPI Suite estimate, program KOCWIN v2.00, IUCLID sect. 5.4.1);

The PNEC sediment freshwater was calculated to 0.1854 mg/kg ww. This value was converted to dry weight (conversion factor of 4.6).

 

PNEC sediment (marine water)

According to chapter R10.5.3.1 of TGD "Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment", the PNEC sediment can provisionally be calculated in the absence of data for sediment-dwelling organisms using the equilibrium partitioning method (EPM).

PNEC derivation following procedures of TGD (R.10 and R.16):

PNEC water (marine water): 0.0000236 mg/L,

Koc: 36108 (EPA EPI Suite estimate, program KOCWIN v2.00, IUCLID sect. 5.4.1);

The PNEC sediment marine water was calculated to 0.01854 mg/kg ww. This value was converted to dry weight (conversion factor of 4.6).

 

PNEC soil

According to chapter R10.6.1 of TGD "Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment", the PNEC soil can provisionally be calculated in the absence of data for soil organisms using the equilibrium partitioning method (EPM).

PNEC derivation following procedures of TGD (R.10 and R.16):

PNEC water (freshwater): 0.000236 mg/L,

Koc: 36108 (EPA EPI Suite estimate, program KOCWIN v2.00, IUCLID sect. 5.4.1),

Vapour pressure: 1.422 Pa (OECD 104, IUCLID sect. 4.6)

Water solubility: 0.125 mg/L (EU Method A.6, IUCLID sect. 4.8)

Molecular weight: 212.33 g/mol

The PNEC soil was calculated to 0.1504 mg/kg ww. This value was converted to dry weight (conversion factor of 1.13).

Conclusion on classification

Diisopropylnaphthalene shows acute aquatic toxicity at loading range between 1 - 10 mg/L. Furthermore, the chronic toxicity is between 0.01 - 0.1 mg/L with a NOEC at 0.0118 mg/L. The latter triggers classification for chronic environmental hazards based on experimental evidence along with "non-rapid degradability", hence according to Regulation (EC) No 1272/2008 to be labelled with H410, Category Aquatic Chronic 1.