(trans(trans))-4'-vinyl-4-(4-methylphenyl)bicyclohexyl

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

There are no data information requirements for long term toxicity in aquatic invertebrates with the registered substance.
However, the available data on acute aquatic toxicity in all three trophic levels revealed that there are no effects observed in any of the tested species and under the conditions of the studies when tested up to the water solubility of the test item.
Since the test item has a very low water solubility and a logPow > 8.6 it is shown that long term effects in aquatic organisms should are be excluded for the test item.

There are no data available on long term toxicity in aquatic invertebrates with the test item. However, data with a structural analogue substance are available and are applied following REACH Annex XI Section 1.5 Read-Across.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The test item and the structural analogue substance share same cyclic chemical key structures with only some modifications in their degree of derivatisation. Where the target substance has vinyl- and methyl substituents, the source substances is substituted with fluor and in addition the middle structure is a oxigenated heterocycle instead of cyclohexane structure. Both modifications contribute to an increased water solubility of the source substance and are further expected to inhance their toxicological activity due to more potential functionialities within the molecular structure. Thus, and based on its structure the source substance is considered to reflect a worst case compared to the target substance in regards to its aquatic toxicity.

2. DATA MATRIX

Target substance:
Water solubility: 0.005 mg/L
logPoW: 8.6 (at 20 °C)

Source substance:
Water Solubility: n. a. (> target substance based on oxygenated heterocycle and halogenation degree)
logPow: 7.3 (at 25 °C)

For more details please refer to the disseminated REACH registration dossier of the source substance.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Description of key information

Long-term toxicity to aquatic invertebrates (read-across): NOEC > 100 mg/L (reference 6.1.4 -1).

Additional information

The toxic effects of the test item on the survival and reproduction rate of Daphnia magna were determined during an exposure period of 21 days. The Daphnia were exposed in a semi static test to an aqueous test medium containing the test item at the highest concentration, which could be dissolved in test water. The mortality rate, the reproduction rate and symptoms of intoxication were compared with corresponding parameters in the control. The GLP compliant study was performed according to OECD TG 211.

In the control and in the test solution (a filtrate of a supersaturated stock suspension of nominal 100 mg/L) all Daphnia survived until the end of the test. The first young Daphnia released from their parent animals were recorded in the control and in the only test concentration at the observation on day 8. The mean reproduction rate of those Daphnia in the control was 105.1 + 16.2 (mean ± SD) alive off-spring per adult. In the test solution, the mean reproduction rate was 111.5 ± 12.9 (mean ± SD) alive off-spring per adult. Thus, no significant toxic effect of the test item on the mean reproduction rate was determined.

Taking into account the survival rates and the reproduction rates of the test animals, the test material showed no toxic effects up to its solubility limit after the exposure period of 21 days. Therefore, the 21-days NOEC was determined to be at least up to the solubility limit of the test substance in test water. The NOEC might even be higher than the solubility limit of the test item in test water. The 21-days LOEC is clearly higher than the solubility limit of the test material in water.