Registration Dossier

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.327 mg/L
Assessment factor:
1
Extrapolation method:
sensitivity distribution
PNEC freshwater (intermittent releases):
0.327 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.327 mg/L
Assessment factor:
1
Extrapolation method:
sensitivity distribution

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
6.58 mg/L
Assessment factor:
1
Extrapolation method:
sensitivity distribution

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
12.46 mg/kg sediment dw
Assessment factor:
1
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
12.46 mg/kg sediment dw
Assessment factor:
1
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:
2.31 mg/kg soil dw
Assessment factor:
1
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

PNECs were derived for freshwater, saltwater, sediment, and soil using the Petrotox model or equilibrium partitioning calculations.

Conclusion on classification

The lowest 96hr LC50 for fish is 2.6 mg/l. The lowest 48hr EC50 forDaphnia magnais 3.62 mg/l. The lowest 72 or 96hr ErC50 for algae is 3.2 mg/l. However, a 24hr EC50 forDaphnia magnaof 1 mg/l is reported for o-xylene. A second study with o-xylene reports a 48hr EC50 of 3.82 mg/l forDaphnia magna. Both these studies with the same test organism are considered valid. None of the LC or EC50 from the acute ecotoxicity tests conducted with the xylene isomersor ethylbenzeneare less than 1 mg/L.

Data on the xylene isomers and ethylbenzene indicates that biodegradation is rapid, and that they will partition to the air from water, further reducing their potential for exposure. An experimentally determined BCF for mixed xylenes in fish gave a result of 29, indicating a low potential for bioaccumulation. Taken together with the acute toxicity results, these results would not result in a classification for acute or chronic hazard to the environment for the streams in this category.

However, on 10thMarch 2011 Commission Regulation (EC) No 1272/2008 [CLP Regulations] was amended. The new criteria for environmental classification state that if chronic data is available this should be used to determine the chronic classification. This category has a complete chronic data set, read across from the xylene isomers and ethyl benzene. The lowest chronic effect is a 72 hour NOEC of 0.44 mg/Lfor algae.This results in a chronic Category 3 classification under the CLP Regulations. This has been added as a self classification to the dossier.