1-(2,6-bis(4-tolyl)-1,3-dioxano(5,4-d)-1,3-dioxan-4-yl)ethane-1,2-diol

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.003 mg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.001 mg/L

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:

100 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

no hazard identified

Sediment (marine water)

Hazard assessment conclusion:

no hazard identified

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

1 mg/kg soil dw

Assessment factor:

1 000

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

See justification of PNECs.

As the algae study can be considered to provide a chronic endpoint, it was considered applicable to use the algal NOEC as a chronic endpoint (along with the Daphnia reproduction study), in assigning assessment factors for aquatic PNECs.

Conclusion on classification

The substance has been evaluated for environmental classification against the current CLP criteria (Regulation (EC) No 1272/2008)

It is considered that a classification of Chronic Category 2 is appropriate based on the available data.

Based on the results of acute testing in fish, daphnia and algae no acute aquatic classification is required, as no effects were observed at the limit of solubility (i.e. the highest obtainable test concentration) in these studies.

Based on the results of the acute toxicity testing, ready biodegradation and log Pow the 'safey net' classification of Chronic Category 4 is not required, as although the substance is poorly soluble and no effects were seen at the limit of solubility in the acute studies and the substance is not readily biodegradable, the log Pow of 2.51 is below the classification criteria for log Pow ( ≥ 4).

However, adequate chronic toxicity data is available from a 21 -day Daphnia reproduction study.

In this study Daphnia magna were exposed to an aqueous solution of the test material over a range of test concentrations of 0.0040, 0.013, 0.040, 0.13 and 0.40 mg/l for a period of 21 days. The test material solutions were prepared by producing a saturated solution with a nominal concentration of 0.40 mg/l. The remaining test concentrations were prepared by dilution of the saturated solution.

The "Lowest Observed Effect Concentration" was considered to be 0.40 mg/l on the basis that at this test concentration significantly fewer live young per adult were produced when compared to the control.

The "No Observed Effect Concentration" was considered to be 0.13 mg/l on the basis that at this test concentration there were no significant mortalities (immobilisation) observed in the parental generation (P₁) and that there were no significant differences between the control and the 0.13 mg/l test group in terms of numbers of live young produced per adult by Day 21.

The NOEC of 0.13 mg/l is sufficient for classification based on the CLP criteria given in Table 4.1.0, b) i) of the CLP regulation, which states that:

Non-rapidly degradable substances for which there are adequate chronic toxicity data available, Chronic Category 2 is applicable when the chronic NOEC for crustecea is >0.1 to ≤1 mg/l.

Therefore, the NOEC of 0.13 mg/l obtained from the Daphnia reproduction study means the substance should be classified as Aquatic Chronic Category 2 (H411: Toxic to aquatic life with long lasting effects).

EC₁₀ values from chronic studies can also be used for classification instead of the NOEC value. No EC₁₀ value was stated in the Daphnia reproduction study, but have been calculated based on the study data.

The EC₁₀ has been based on the number of juveniles per adult. This endpoint was used for the NOEC and is considered the most relevant effect.

 

The EC₁₀ was calculated to be 0.29 mg/l.

 

As EC₁₀ or NOEC should be used for chronic classification, based on the calculated EC₁₀ of 0.29 mg/l, classification in Chronic Category 2 would still apply. As the EC₁₀ is also below the water solubility of the substance, it should be considered as a relevant result for classification.