1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

2.6 µg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

18 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.26 µg/L

Assessment factor:

500

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

5.83 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

5 mg/kg sediment dw

Assessment factor:

50

Extrapolation method:

assessment factor

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.5 mg/kg sediment dw

Assessment factor:

500

Extrapolation method:

assessment factor

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

10.4 mg/kg soil dw

Assessment factor:

10

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

3.3 mg/kg food

Assessment factor:

300

Additional information

Based on the available data for the aquatic compartment, Octopirox is most toxic to daphnia with an acute EC50 (48h) river water of 1.8 mg/L and a chronic NOEC reproduction (21d) river water of 0.13 mg/L.

Based on the available data for the freshwater sediment compartment Octopirox is equally toxic to the endobenthic worm Lumbriculus variegatus and the nematode Caenorhabditis elegans both with an NOEC reproduction (28d) of 250 mg/kg dw.

Based on the available data for the terrestrial compartment Octopirox is most toxic to soil microorganisms with an EC10 of 104 mg/L soil dw.

Conclusion on classification

Short-term effects

The Environmental classification with respect to short-term effects has to take into account the lowest acute value for aquatic species which is the Daphnia EC50 (48h) of 1.8 mg/L (see Section 6.1.5). This study was carried out in river water because a test in reconstituted water is technically not feasible as Octopirox reduces the nutrient ions. This means that the classification has to be based on the river water results.

In addition Octopirox is not readily biodegradable but is rapidly degraded by direct photolysis in water (DT50 0.9d, complete desintegration of the pyridine ring). In addition Octopirox an octanol water partitioning coefficient of 3.86 was measured (see Section 4.7) and therefore bioaccumulation is not expected. Although the bioconcentration criteria of DSD 67/548/EECis formally fulfilled (Log Kow >=3) it is scientifically not justified to assign a R53 especially as the more modern bioconcentration criteria of CLP2011/286/EU(log Kow >= 4) is not fulfilled and the substance Octopirox is rapidly photolyzed in water. From a scientific point of view it makes not much sense to classify Octopirox according 67/548/EEC as a substance with long-term effects (R51/53) and under CLP2011/286/EU assign no classification. This would also confuse the down-stream user of Octopirox.

Based on these facts an environmental classification should be based on the ecotoxicity only as the criteria for long-term effects are not fulfilled.

Proposed classification according DSD 67/548/EEC for Short-term effects:

formally R51/53, from a scientific point of view: NO CLASSIFICATION

Proposed classification according CLP2011/286/EU for Short-term effects:

NO CLASSIFICATION

 

Long-term (chronic) effects

According to the 2^ndATP of CLP (286/2011/EU) there are different approaches for the environmental classification of Long-term effects depending on the number of available chronic ecotoxicity data. As two chronic ecotoxicity data for Octopirox are available two approaches have to be checked: a) the approach based on acute data only and b) the approach using the chronic ecotoxicity data. The more stringent result has to be used for the Environmental classification of Long-term effects. In this case the classification on the chronic data is based on the NOEC Daphnia( 21d) 0.13 mg/L (see Chapter 7.1.1.2.2) which leads for substances which are rapidly degraded to Chronic Category 3 Classification. In Summary

Proposed classification according DSD 67/548/EEC for Long-term effects:

formally R51/53, from a scientific point of view: NO CLASSIFICATION

Proposed classification according CLP2011/286/EU for Long-term effects:

Chronic Category 3, H412

OVERALL ENIVIRONMENTAL CLASSIFICATION

Proposed classification according DSD 67/548/EEC for Short-term & Long-term effects:

formally R51/53, from a scientific point of view: NO CLASSIFICATION

Proposed classification according CLP2011/286/EU for Short-term & Long-term effects:

Chronic Category 3, H412